Noncontact Atomic Force Microscopy - Yale School of Engineering ...

12 th International Conference on 

Noncontact Atomic Force Microscopy 

and 

Casimir 2009 Workshop 

CONFERENCE PROGRAM 

August 10-14, 2009 � Yale University, New Haven, CT, USA

Institutional Sponsors 

Yale Center for Research 

on Interface Structures 

and Phenomena 

Past Conferences 

Osaka, Japan (1998) 

Pontresina, Switzerland (1999) 

Hamburg, Germany (2000) 

Kyoto, Japan (2001) 

Montreal, Canada (2002) 

Dingle, Ireland (2003) 

Seattle, USA (2004) 

Osnabrück, Germany (2005) 

Kobe, Japan (2006) 

Antalya, Turkey (2007) 

Madrid, Spain (2008) 

Forthcoming Conference 

Kanazawa, Japan (2010) 

Udo D. Schwarz 

Dept. of Mechanical Engineering 

Yale University 

New Haven, CT 06515, USA 

udo.schwarz@yale.edu 

Cover Page: Banner of Yale 

University (1.8 µm � 1.8 µm), 

written into a PMMA film by 

dynamic force microscopy. 

Image by M. Heyde & 

U. D. Schwarz 

Left: Harkness Tower on 

Yale Campus. 

• Yale School of Engineering 

• Departments of Mechanical, Electrical, 

and Chemical Engineering 

• Department of Physics 

Endorsed 

Topical 

Conference 

www.avs.org

Welcome 

Dear conference participant: 

Welcome to the 12th International Conference on Non-Contact Atomic Force Microscopy 

(NC-AFM 2009), which is held on historic Yale University campus in New Haven, CT, USA. 

It continues a series of international conferences constituted 1998 in Osaka, Japan. Since 

then, the annual NC-AFM conferences have been established as the leading events for 

NC-AFM related topics. This year’s meeting has again attracted a large number of 

participants (over 130 attendees from 17 countries), who are contributing 43 oral and 71 

poster presentations. 15 additional talks are provided by the Satellite Workshop on Casimir 

Forces and Their Measurement, and seven companies feature their newest products in an 

exhibition. 

Like in other years, the scientific program showcases the rapid development that NC-AFM 

enjoys. Various experimental improvements such as high-stability measurements 

performed at low temperatures, novel stiff self-sensing oscillators with atomically controlled 

tips that allow chemical identification and tunneling current collection, drift compensation by 

forward-feedbacking, atom tracking, and post-acquisition drift correction, and all-digital 

high-speed, low-noise electronics enable a new level of sophistication in imaging, analysis, 

and atom manipulation. Progress is particularly remarkable for high-resolution data 

acquisition in liquids, demonstrating that NC-AFM is leaving its ultrahigh vacuum niche. 

The main conference is complemented by a Satellite Workshop on Casimir Forces and 

Their Measurement (Casimir 2009). Designed to stimulate discussion between the Casimir 

and the NC-AFM communities, the Casimir 2009 workshop has been well received (87 

participants). Credit for initiating this event goes to Woo-Joong Kim, who was aided in its 

organization by Alex Sushkov and Steven K. Lamoreaux. 

Contributions by many key players were indispensable in realizing this conference, among 

them the ones by the members of the Local Organizing Committee (Eric I. Altman, Hong X. 

Tang, and Woo-Joong Kim) and by the team of the Yale Conference Service under the 

supervision of Susan Adler. Special thanks go to Mehmet Baykara for his help with various 

practical aspects such as the design of this abstract booklet. We were also fortunate to 

receive significant support from numerous Yale entities, whose generous financial 

assistance made this conference possible, from the European Science Foundation through 

its “New Trends and Applications of the Casimir Effect” program, and from the American 

Vacuum Society, which arranged for the publication of the conference proceedings. The 

complete list of institutional sponsors can be found opposite to this page; corporative 

sponsors and exhibitors are listed on page 9. 

We hope that you will enjoy the conference and have a wonderful time in New Haven. 

Udo D. Schwarz, Conference Chair 

1

2 

Contents 

Welcome 1 

Topics 3 

Committees 4 

General Information 6 

Local Maps 8 

Exhibitors 9 

Proceedings 10 

Conference Program 13 

Oral Presentations 28 

Poster Presentations 91 

Author Index 164 

List of Participants 169 

Advertisement 174

Topics 

• Atomic resolution imaging of surfaces, thin films, and molecular 

systems 

• Measuring tip-sample interaction potentials and mapping force fields 

• High-resolution imaging of clusters, biomolecules, and biological 

systems 

• High-resolution imaging and spectroscopy in liquid environments 

• Novel instrumentation and measurement techniques in dynamic AFM 

• Small amplitude measurements 

• Lateral force measurements using dynamic methods 

• Atomic- and molecular-scale manipulation 

• Theoretical analysis of contrast mechanisms; forces & tunnelling 

phenomena 

• Simulation of images and virtual AFM systems 

• Mechanisms for damping and energy dissipation 

• Amplitude modulation versus frequency modulation imaging 

• Measuring nanoscale charges, work functions, and magnetic 

properties 

• Characterization and modification of force microscopy tips at the 

atomic scale 

3

Committees 

Conference Chairman 

Udo Schwarz Yale University (USA) 

Local Organizing Committee 

Eric I. Altman Yale University (USA) 

Hong X. Tang Yale University (USA) 

Woo-Joong Kim Yale University (USA) 

Satellite Workshop Organization 

Woo-Joong Kim Yale University (USA) 


Alex Sushkov Yale University (USA) 

Steven K. Lamoreaux Yale University (USA) 

International Steering Committee 

Franz Giessibl University of Regensburg (Germany) 

Peter Grütter McGill University (Canada) 

Ernst Meyer University of Basel (Switzerland) 

Seizo Morita Osaka University (Japan) 

Hiroshi Onishi Kobe University (Japan) 

Ahmet Oral Sabanci University (Turkey) 

Rubén Peréz Universidad Autonoma de Madrid (Spain) 

Michael Reichling University of Osnabrück (Germany) 

Alexander Schwarz University of Hamburg (Germany) 


Alexander Shluger University College London (UK) 

4

Committees 

Program Committee 

Jaime Colchero Universidad de Murcia (Spain) 

Oscar Custance National Institute for Material Science (Japan) 

Takeshi Fukuma Kanazawa University (Japan) 

Hendrik Hölscher Karlsruhe Research Laboratory (Germany) 

Sascha Sadewasser Helmholtz Institute Berlin (Germany) 

André Schirmeisen University of Münster (Germany) 

Santiago Solares University of Maryland (USA) 

Yasuhiro Sugawara Osaka University (Japan) 

Masaru Tsukada Waseda University (Japan) 

Hirofumi Yamada Kyoto University (Japan) 

Conference Proceedings Editors 

Hendrik Hölscher Karlsruhe Research Laboratory (Germany) 

Udo D. Schwarz Yale University (USA) 

Conference Organization 

Tara Schule, Joanne Dupee, Roberta Hudson, and Susan Adler, Yale Conference 

Services 

5

General Information 

Conference Venue: 

Talks will be held in Davies Auditorium in the basement of Yale University’s Becton Center, 

15 Prospect Street, New Haven, CT 06511 (see the maps page 8 for the exact location). 

For easiest access, follow the signs around the building to the lower courtyard located 

between Becton Center and the rear building (Dunham Laboratory, 10 Hillhouse Avenue). 

There, you will find the main entrance to the conference area, which is indicated by the red 

arrow in the satellite picture. For the auditorium, please turn left after entering the doors. In 

contrast, turning right twice will lead you to the J. Robert Mann Jr. Engineering Student 

Center, where coffee breaks and parts of the exhibition are taking place. Poster sessions 

and luncheons will be held in Commons Hall at the corner of Grove and College Streets 

(the building with the dome opposite Becton Center). Please keep in mind that smoking is 

not allowed in any Yale University building, including Davies Auditorium, the Mann Student 

Center, and Commons Hall. 

Registration: 

The registration desk in the foyer of Davies Auditorium (see above) will be staffed 07:45- 

18:00 (Monday), 08:00-12:00 (Tuesday), and 08:30-09:00 (Wednesday through Friday). 

Welcome Party: 

We invite all conference participants to a casual welcome party with reception and dinner 

(barbeque) on Monday, August 10, 2009, between 18:30 and 20:30. The exact location will 

be announced ahead of time via email and on the web. 

Conference Banquet: 

Conference banquet will be held on Thursday, Aug. 13 th , 2009, 18:30-22:00 at Sterling 

Memorial Library (SML) on Yale campus. Please see the maps on page 8 for the location of 

SML. 

6

General Information (cont.) 

Oral Presentations: 

Oral presentations will be scheduled for 20 minutes each including a 5-minute discussion 

for sessions during the NC-AFM conference (August 11-14). For the specialized Casimir 

workshop sessions on August 10, talks will be 25 minutes each. An LCD projector is 

available in the conference room, but all speakers are required to bring their own laptops. 

Poster Presentations: 

Two Poster sessions will be held during the conference on Tuesday, August 11, and 

Wednesday, August 12, 2009. The available size for posters will be 1.2 m x 1.2 m. Pins for 

mounting the poster on the board will be provided. 

Internet Access: 

Wireless internet access will be available in Davies Auditorium and the exhibition areas. 

Detailed instructions for connecting to the internet will be distributed with your conference 

material. Also, a number of desktop computers will be available in the exhibition area and a 

nearby computer cluster room. A guest login ID and a personal password, which allows you 

to connect to the internet from these computers, will be handed to each participant at the 

registration desk. 

7

Local Maps 

8

Exhibitors 

9

Proceedings 

Both NC-AFM Conference and Casimir Workshop participants are invited to contribute an 

article to the conference proceedings, which will be published in the Journal of Vacuum 

Science and Technology B (JVST B). Publishing your work in the conference proceedings 

represents an excellent opportunity to promote your work, as NC-AFM proceedings have in 

the past always been highly visible and widely cited. This is in particular the case as every 

conference participant (main conference AND Casimir Workshop) will receive a bound 

complementary copy of the proceedings via mail. 

The proceedings will be edited by Hendrik Hölscher, Karlsruhe Research Laboratory, 

Germany, and Udo D. Schwarz, Yale University. Submission deadline is October 16, 

2009, but please contact us at your earliest convenience to let us know about your plans to 

submit a contribution so that we can plan ahead. Publication of the proceedings is 

scheduled for the May/June issue of JVST B in 2010. 

Instructions for preparing manuscripts for the proceedings of the NC-AFM 2009 

Conference: 

1. Submission: Papers will be reviewed according to criteria set by the JVST and must 

meet JVST standards for both technical content and written English. All manuscripts 

for the proceedings must be submitted as a PDF file along with a cover letter 

containing your complete address to the guest editor via email 

(Hendrik.Hoelscher@imt.fzk.de). 

2. Program number: It is important that the submitted manuscript has the program 

number of your contribution to the NC-AFM conference or the satellite conference 

entered in the top-right corner of the title page. 

10

Proceedings (cont.) 

3. Length: Papers can contain up to a nominal total of 20-25 pages of double-spaced 

text, tables, figures, references, abstract, etc. if the submitted paper is longer than 

25 pages, the final decision on acceptance for publication will be made by the JVST 

editors based on the recommendations of the reviewers. 

4. Format: The text should be double-spaced; the font recommended by JVST is 

Times New Roman 12pt. Pages should have one-inch margins on all sides. 

5. Figures and Tables: Each figure and table should be displayed on a separate 

page. Table and figure captions should be listed on a separate page and NOT below 

the table or figure; only the figure/table number must appear with the figure/table. 

6. Footnotes: Authors may include their e-mail addresses along with all other footnotes 

in the following format: Electronic mail: smith@yale.edu 

7. Costs: JVST publishes articles authored by members of the American Vacuum 

Society (AVS) free of charge. Therefore, let us know when submitting whether any of 

the authors is presently AVS member. For submissions where no author is AVS 

member, we will provide a complementary 1-year membership for the paper's 

corresponding author paid for form conference funds. As a result, there will be no 

page charges or other costs for your submission. 

8. Color: Your figures can appear online in color for free. To take advantage of this 

offer, you will need to send the electronic file(s) of your figure(s) within 24 hours of 

receiving your acceptance email from JVST directly to the publisher (the American 

Institute of Physics, AIP). Please do not send anything until you receive notice the 

paper is accepted and has a 9 digit AIP number. Sending color figures in the pdf file 

11

Proceedings (cont.) 

used for the review process does not allow for color reproduction (either online or 

print) at the publishing stage. Only sending AIP the files directly will enable this. A 

“Publisher’s Announcements” email with more details will be sent to you once your 

paper has been accepted. 

9. Materials Index Entries: If applicable, please provide us with at least three material 

terms, which should indicate what materials (i.e., chemical species) are discussed in 

the article. These terms are needed as entries for the JVST Materials Index. 

For more details, please refer to: 

JVST author instructions: www.avs.org/literature.information.aspx 

JVST Word template: www.avs.org/pdf/JVST/eC.doc 

Instructions for this template: www.avs.org/pdf/JVST/eCEinstructions.pdf 

Manuscript deadline: October 16, 2009 

Please submit your manuscript as PDF together with a cover letter containing your 

complete address and information whether or not one of the authors is presently AVS 

member via email to guest editor Dr. Hendrik Hölscher at Hendrik.Hoelscher@imt.fzk.de 

12

Conference 

Program 

13

NC-AFM 2009 

Sessions 

Monday 

August 10 

• Liquids I 

Tuesday 9:20-10:40 

• Force Spectroscopy I 

Tuesday 11:20-12:40 

• Electronic, photonic, & Casimir forces 

Tuesday 14:30-15:50 

• Oxides 

Wednesday 9:00-10:40 

• Carbon-based materials 


Tuesday 

August 11 

14 

Wednesday 

August 12 

• Molecules on insulators 


• Force spectroscopy II 

Thursday 9:00-10:40 

• Forces & charges 

Thursday 11:20-13:00 

• Method development 

Friday 9:00-10:40 

• Liquids II 

Friday 11:20-12:40 

Thursday 

August 13 

Friday 

August 14 

8:30 Registration Registration Registration Registration 

9:00 Opening Remarks M. Heyde A. Campbellova Y. Naitoh 

9:20 T. Fukuma A. Yurtsever F. J. Giessibl S. Torbrügge 

9:40 H. Asakawa R. Pérez G. Langewisch Y. Hosokawa 

10:00 N. Oyabu R. Bechstein A. Baratoff E. Tsunemi 

10:20 M. Tsukada S. Sadewasser S. Kawai U. Zerweck 

10:40 Coffee Break Coffee Break Coffee Break Coffee Break 

11:20 D. Ebeling U. D. Schwarz A. Sweetman S. Nishida 

11:40 A. Schirmeisen P. Jelínek L. Gross S. Ido 

12:00 Y. Sugimoto M. Ashino Y. Miyahara E. T. Herruzo 

12:20 Y. Sugawara P. Pou T. Trevethan K. Fukui 

12:40 A. Bettac Closing Remarks 

13:00 

Lunch 

110 min. 

(12:40-14:30) 

Lunch 

110 min. 

(12:40-14:30) 

14:30 

A. Parsegian 

A. Kühnle 

14:50 

(invited) 

A. Schwarz 

15:10 Th. Glatzel Ch. Loppacher 

15:30 H. Hölscher C. J. Gómez 

15:50 

| 

18:00 

C 

A 

S 

I 

M 

I 

R 

W 

O 

R 

K 

S 

H 

O 

P 

18:30-20:30 

Welcome 

Reception/Dinner 

Poster Session I Poster Session II 

Lunch 

90 min. 

(13:00-14:30) 

18:30-22:00 

Conference 

Banquet

Program Summary of the NC-AFM 2009 Satellite Workshop on 

Casimir Forces and Their Measurement 

Monday sessions only; Tuesday sessions are joint with the NC-AFM Conference (see the main 

conference program for listing). Note in particular that the Casimir workshop’s second invited talk, 

given by Adrian Parsegian (NIH, USA), will take place Tuesday 14:30-15:10. 

Monday, August 10 

7:45 Registration 

8:50 Opening Remarks 

9:00 Rudi Porgornik (University of Ljubljana, Slovenia), invited 

9:30 Noah Graham (Middlebury College, USA) 

9:55 Kimball Milton (University Oklahoma, USA) 

10:20 

Coffee Break 

10:50 Raul Esquivel-Sirvent (Universidad Nacional Autónoma, Mexico) 

11:15 Diego Dalvit (Los Alamos National Laboratory, USA) 

11:40 Rick Rajter (MIT, USA) 

12:05 Maarten de Boer (Sandia National Laboratory, USA) 

12:30 

Lunch (12:30-14:30) 

14:30 Hong Tang (Yale University, USA) 

14:55 Alessandro Siria (CNRS, France) 

15:20 Arvind Narayanaswamy (Columbia University, USA) 

15:45 


16:15 Sven de Man (VU University Amsterdam, Netherlands) 

16:40 Gauthier Torricelli (University of Leicester, UK) 

17:05 Ho Bun Chan (University of Florida, USA) 

17:30 Peter van Zwol (University of Groningen, Netherlands) 

17:55 Woo-Joong Kim (Yale University, USA) 

18:30-20:30 

Welcome Reception with Dinner 

15


Satellite Workshop on Casimir Forces and 

Their Measurement 


Session I Chair: W.-J. Kim 

9:00 Non-retarded and retarded interactions between dielectric cylinders 

Rudi Podgornik 

9:30 Casimir Forces from Scattering Theory 

Noah Graham 

9:55 Multiple Scattering Casimir Force Calculations between Layered and Corrugated Materials 

Kimball Milton 

10:20 Coffee Break 

Session II Chair: R. Podgornik 

10:50 Drude corrections to Casimir force calculations in liquids 

Raul Esquivel-Sirvent 

11:15 Dispersive Casimir interactions between atoms and surfaces 

Diego Dalvit 

11:40 Van der Waals with a twist: how nanotube chirality impacts interaction strength 

Rick Rajter 

12:05 Using Casimir and capillary forces to model adhesion of MEMS cantilevers 

Maarten de Boer 

12:30 Lunch Break 

Session III Chair: A. Parsegian 

14:30 Measuring “Virtual Photon” Forces with “Real Photon” Forces 

Hong Tang 

14:55 Near-field radiative heat transfer 

Alessandro Siria 

15:20 Near-field radiative transfer measurements and implications for Casimir force 

measurements 

Arvind Narayanaswamy 


16


Satellite Workshop on Casimir Forces and Their Measurement (cont.) 

Session IV 

17 

Chair: D. Dalvit 

16:15 Tricks and facts in a high precision measurement of the Casimir force with transparent 

conductors 

Sven de Man 

16:40 Measurements of the Casimir force gradient by AFM for Different Materials 

Gauthier Torricelli 

17:05 Measuring the topological dependence of the Casimir force on nanostructured silicon 

surfaces 

Ho Bun Chan 

17:30 Short range Casimir force measurements under ambient conditions and liquid 

environments 

Peter van Zwol 

17:55 Contact potential difference in a Casimir force measurement: How do we deal with it? 

Woo-Joong Kim 

Welcome Reception with Dinner (18:30-20:30)

Tuesday, August 11 


Liquids I 

9:20 3D Scanning Force Microscopy at Solid/Liquid Interface 

T. Fukuma, Y. Ueda 

18 

Chair: H. Hölscher 

9:40 Anisotropic Hydration of Biological Molecules Visualized by Three-Dimensional Scanning 

Force Microscopy 

H. Asakawa,Y. Ueda, T. Fukuma 

10:00 Experimental and Theoretical Studies on 3D Hydration Structures on Muscovite Mica 

Surfaces in Aqueos Solution 

N. Oyabu, K. Kimura, S. Ido, K. Suzuki, K. Kobayashi, T. Imai, H. Yamada 

10:20 Theory of Tip-Sample Interaction Force Mediated by Water 

M. Tsukada, M.Harada, K.Tagami 


Force Spectroscopy I 

11:20 Dynamic Force Spectroscopy of Single Chain-like Molecules 

D. Ebeling, H. Fuchs, F. Oesterhelt, H. Hölscher 

11:40 Spatial force fields above a single atom defect 

A. Schirmeisen, D. Weiner 

12:00 Simultaneous measurement of force and tunneling current 

D. Sawada, Y. Sugimoto, K.-I. Morita, M. Abe, S. Morita 

12:20 Atom Manipulation on Cu(110)-O Surface with LT-AFM 

Y. Sugawara, Y. Kinoshita, Y. J. Li, Y. Naitoh, M. Kageshima 


Chair: F. J. Giessibl 

Electronic, Photonic, & Casimir Forces Chair: S. Morita 

14:30 Water, Ions, Membranes, Real Metals, Finite Temperature: Is there ever a pure Casimir 

force? (Invited) 

Adrian Parsegian 

15:10 Short and medium range electrostatic forces analyzed by Kelvin probe force microscopy 

Th. Glatzel, S. Kawai, S. Koch, A. Baratoff, E. Meyer 

15:30 The Effective Quality Factor in Dynamic Force Microscopes with Fabry-Perot 

Interferometer Detection 

H. Hölscher, P. Milde, U. Zerweck, L. M. Eng, R. Hoffmann 

Poster Session I (15:50 – 18:00) 

Chair: A. Oral

Wednesday, August 12 

Oxides Chair: A. Schwarz 

9:00 Imaging Single Atoms on Oxide Surfaces – Gold on Alumina/NiAl(110) 

M. Heyde, G. H. Simon, Th. König, H.-J. Freund 

9:20 Site-specific force spectroscopy on TiO2 (110) surface at low-temperature 

A. Yurtsever, A. Pratama, Y. Sugimoto, M. Abe, S. Morita 

9:40 Character of the short-range interaction between a silicon based tip and the TiO2(110) 

surface: a DFT study 

C. Gozalez, P. Jelínek, R. Pérez 

10:00 True atomic resolution imaging on an application-oriented system: Understanding 

photocatalytic reactivity of transition-metal doped TiO2 

R. Bechstein, M. Kitta, J. Schütte, H. Onishi, A. Kühnle 

10:20 Local surface photovoltage spectroscopy of molecular clusters using Kelvin probe force 

microscopy 

S. Sadewasser, M. Ch. Lux-Steiner 


Carbon-based Materials Chair: M. Reichling 

11:20 Why is Graphite so Slippery? Gathering Clues from Three-Dimensional Lateral Forces 

Measurements 

U. D. Schwarz, M. Z. Baykara, T. C. Schwendemann, B. J. Albers, N. Pilet, E. I. Altman 

11:40 Theoretical DFT simulations of the STM/AFM atomic scale imaging on graphite 

V. Rozsíval, M. Ondráček, P. Jelínek 

12:00 Atomic-Resolution Damping Force Spectroscopy on Nanotube Peapods with Different 

Tube Diameters 

M. Ashino, R. Wiesendanger, A. N. Khlobystov, S. Berber, D. Tománek 

12:20 Theoretical study of the forces and atomic configurations of NC-AFM experiments on lowdimension 

carbon materials 

P. Pou, R. Perez 


Molecules on Insulators Chair: R. Perez 

14:30 Anchoring highly polar molecules onto an ionic crystal 

J. Schütte, R. Bechstein, M. Rohlfing, M. Reichling, A. Kühnle 

14:50 Steering the formation of molecular nanowires and compact nanocrystallites on NaCl(001) 

S. Fremy, A. Schwarz, K. Laemmle, R. Wiesendanger, M. Prosenc 

15:10 2-Dimensional growth of phenylenediboronic acid assisted by H-bonding 

R. Pawlak, L. Nony, F. Bocquet, M. Sassi, V. Oison, J.-M. Debierre, Ch. Loppacher, L. 

Porte 

15:30 Molecular scale dissipation in oligothiophene monolayers measured by dynamic force 

microscopy 

C. J. Gómez, N. F. Martínez, W. Kamiński, C. Albonetti, F. Biscarini, R. Perez, R. Garcia 

Poster Session II (15:50 – 18:00) Chair: Y. Sugawara 

19

Thursday, August 13 

Force Spectroscopy II 

20 

Chair: P. Grütter 

9:00 Dependence of the atomic scale image of a Si adatom on the tip apex termination: a DFT 

study 

A. Campbellova, P. Pou , R. Pérez, P. Klapetek, P. Jelínek 

9:20 AFM probe tips with a small front atom 

T. Hofmann, J. Welker, M. Ternes, C. P. Lutz, A. J. Heinrich, F. J. Giessibl 

9:40 Intramolecular features of organic molecules characterized by force field spectroscopy: 

The case of PTCDA on Cu and Ag 

G. Langewisch, D.-A. Braun, D. Weiner, B. Such, H. Fuchs, A. Schirmeisen 

10:00 Analysis of bimodal and higher mode small-amplitude near-contact AFM and energy 

dissipation 

S. Kawai, A. Baratoff, Th. Glatzel, S. Koch, B. Such, E. Meyer 

10:20 Adhesion-induced energy dissipation and atom-tracked tip changes 

S. Kawai, Th. Glatzel, S. Koch, B. Such, A. Baratoff, E. Meyer 


Forces & Charges 

Chair: H. Onishi 

11:20 Combined Qplus-AFM and STM imaging of the Si(100) surface: Activating the c(4x2) to 

p(2x1) transition with subnanometre oscillation amplitudes 

A. Sweetman, S. Gangopadhyay, R. Danza, P. Moriarty 

11:40 Measuring Atomic Charge States by nc-AFM 

L. Gross, F. Mohn, P. Liljeroth, J. Repp, F. J. Giessibl, G. Meyer 

12:00 Mechanism of Dissipative Interaction by Tunneling Single-Electrons 

Y. Miyahara, L. Cockins, S. D. Bennett, A. A. Clerk, S. A. Studenikin, P. Poole, A. 

Sachrajda, P. Grütter 

12:20 Controlling electron transfer processes on insulating surfaces with the NC-AFM 

Th. Trevethan, A. Shluger 

12:40 NC-AFM imaging with atomic resolution in a temperature range between 5 K and 1083 K 

A. Bettac, A. Feltz 


Guided Yale Campus Walking Tour (16:00-17:30) 

Conference Banquet (18:30 – 22:00)

Friday, August 14 

Method Development Chair: A. Schirmeisen 

9:00 Atomic scale elasticity mapping of Ge(001) surface by multifrequency FM-AFM 

Y. Naitoh, Z. Ma, Y. Li, M. Kageshima, Y. Sugawara 

9:20 Small amplitude atomic resolution NC-AFM imaging and force spectroscopy experiments 

using a stiff piezoelectric force sensor 

S. Torbrügge, J. Rychen, O. Schaff 

9:40 Determination of the Optimum Spring Constant and Oscillation Amplitude for 

Atomic/Molecular-Resolution FM-AFM 

Y. Hosokawa, K. Kobayashi, H. Yamada, K. Matsushige 

10:00 Visualization of Anisotropic Conductance in Polydiacetylene Crystal by Two-probe FM- 

AFM/KFM 

E. Tsunemi, K. Kobayashi, K. Matsushige, H. Yamada 

10:20 Scattering Scanning Near-Field Optical Microscopy performed by NC-AFM 

U. Zerweck, S. C. Schneider, M. T. Wenzel, H.-G. von Ribbeck, S. Grafström, R. Jacob, S. 

Winnerl, M. Helm, L. M. Eng 


Liquids II Chair: T. Fukuma 

11:20 Atomic resolution dynamic lateral force microscopy in liquid 

S. Nishida, D. Kobayashi, N. Okabe, H. Kawakatsu 

11:40 Molecular-scale Investigations of Biomolecules in Liquids by FM-AFM 

S. Ido, N. Oyabu, K. Kobayashi, Y. Hirata, M. Tsukada, K. Matsushige, H. Yamada 

12:00 Bimodal AFM imaging of antibodies and chaperonins in liquids 

E. T. Herruzo, C. Dietz, J. R. Lozano, R.Garcia 

12:20 Redox-state Dependent Reversible Change of Molecular Ensembles in Water Solution by 

Electrochemical FM-AFM 

K.-I. Umeda, Y. Yokota, K.-I. Fukui 

12:40 Closing Remarks 

21

POSTER Session I (Tuesday) 

Force Spectroscopy 

P.I-01 Force and Tunneling Current Measurements on the Semiconductor Surface 

D. Sawada, Y. Sugimoto, K.-I. Morita, M. Abe, S. Morita 

P.I-02 Force Map of Atomic Force Microscopy on Si(111)-(5x5)-DAS Surface 

A. Masago, M. Tsukada 

22 

Chair: A. Oral 

P.I-03 From non-contact to atomic scale contact between a Si tip and a Si surface analyzed using 

an nc-AFM and nc-AFS based instrument 

T. Arai, K. Kiyohara, T. Sato, S. Kushida, M. Tomitori 

P.I-04 Improved atomic-scale contrast via bimodal dynamic force microscopy 


P.I-05 Static cantilever deflection in dynamic force microscopy 


P.I-06 Resonance frequency shift due to tip-sample interaction in the thermal oscillations regime 

G. Malegori, G. Ferrini 

P.I-07 Influence of thermal noise on measurements of chemical bonds in UHV-AFM 

P. M. Hoffmann 

P.I-08 Atomic force microscope cantilever resonance frequency shift based thermal metrology 

A. Narayanaswamy, C. Canetta, N. Gu 

Kelvin Probe Microscopy 

P.I-09 Contact potential difference on the atomic-scale probed by Kelvin Probe Force Microscopy: 

an imaging scenario 

L. Nony, A. Foster, F. Bocquet, Ch. Loppacher 

P.I-10 Self-assembled Boronitride Nanomesh on Rh(111) Investigated by Means of Kelvin Probe 


S. Koch, M. Langer, J. Lobo-Checa, Th. Brugger, S. Kawai, B. Such, E. Meyer, Th. Glatzel 

P.I-11 Kelvin probe force microscopy in application to organic thin films: frequency modulation, 

amplitude modulation, and hover mode KPFM 

B. Moores, F. Hane, L. M. Eng, Z. Leonenko 

P.I-12 Resolution enhanced multifrequency electrostatic force microscopy under ambient 

conditions 

X. D. Ding, J. B. Xu, J. X. Zhang 

P.I-13 Deconvolution and Tip Geometry Effects in Atomic- and Nanoscale Kelvin probe Force 

Microscopy 

G. Elias, Y. Rosenwaks, A. Boag, E. Meyer, Th. Glatzel 

P.I-14 Kelvin Force Microscopy Dynamic Behavior and Noise Propagation 

H. Diesinger, D. Deresmes, J.-P. Nys, Th. Mélin 

P.I-15 Charge transfer from doped silicon nanocrystals 

Ł. Borowik, Th. Nguyen-Tran, P. Roca i Cabarrocas, K. Kusiaku, D. Theron, H. Diesinger, 

D. Deremes, Th. Mélin

Poster Session I cont. (Tuesday) 

Instrumentation 

P.I-16 Open source scanning probe microscopy control and data analysis software package 

Gxsm 

P. Zahl 

P.I-17 2 nd generation Dynamic Nanostencil AFM/DFM/STM for in-situ (UHV) resistless patterning 

of nanostructures 

P. Zahl, P. Sutter 

P.I-18 Design of a Variable Temperature Variable Magnetic Field Noncontact Scanning Force 

Microscope for the Characterization of Nanoscale Electronic and Magnetic Phenomena 

P. Staffier, M. Liebmann, J. Falter, N. Pilet, Ch. Ahn, U. D. Schwarz 

P.I-19 An Active Q Control System in Scanning Force Microscopy 

J. Kim, M. Zech, J. E. Hoffman 

P.I-20 Besocke style quartz tuning fork FM-AFM/STM for use in UHV and low temperatures 

S. M. Huston, R. T. Port, K. M. Andrews, Th. P. Pearl 

P.I-21 Design of a Low Temperature Noncontact Atomic Force Microscope Combined with a Field 

Ion Microscope 

J. Falter, D.-A. Braun, H. Hölscher, U. D. Schwarz, A. Schirmeisen, H. Fuchs 

P.I-22 A homebuilt low-temperature STM / tuning fork AFM combination 

M. Lange, J. Schaffert, N. Wintjes, R. Möller 

P.I-23 Development of quartz force sensors for noncontact atomic force microscopy/spectroscopy 

K. Hori, T. Arai, M. Tomitori 

P.I-24 High-Speed Frequency Modulation Atomic Force Microscopy using Wideband Digital 

Phase-Locked Loop Detector 

T. Fukuma, Y. Mitan 

Method Development 

P.I-25 Recent Advances in Multi-Spectral Atomic Force Microscopy 

S. Jesse, N. Balke, P. Maksymovych, O. Ovchinnikov, A.P. Baddorf, S.V. Kalinin 

P.I-26 Deciphering Nanoscale Interactions: Artificial Neural Networks and Scanning Probe 


M. Nikiforov, S. Jesse, O. Ovchinnikov, S. V. Kalinin 

P.I-27 NC-AFM study of a cleaved InAs (110) surface using modified Si probes under ambient 

atmospheric pressure 

Y. Jeong, M. Hirade, R. Kokawa, H. Yamada, K. Kobayashi, N. Oyabu, H. Yamatani, T. 

Arai, A. Sasahara, M. Tomitori 

P.I-28 Dual-Frequency-Modulation AFM Spectroscopy 

G. Chawla, C. A. Wright, S. D. Solares 

P.I-29 Theory of Multifrequency Method in FM-AFM 

Z. Ma, Y. Naitoh, Y. Li, M. Kageshima, Y. Sugawara 

P.I-30 Internal Resonances and Spatio-Temporal Instabilities in Nonlinear Multi-mode NC-AFM 

Dynamics 

O. Gottlieb, S. Hornstein, W. Wu, A. Shavit 

23

Poster Session I cont. (Tuesday) 

P.I-31 Frequency Noise in Frequency Modulation Atomic Force Microscopy 

K. Kobayashi, H. Yamada, K. Matsushige 

P.I-32 Relation between lateral forces and dissipation in FM-AFM 

M. Klocke, D. E. Wolf 

P.I-33 Experimental Study of Dissipation Mechanisms in AFM Cantilevers 

F. Zypman 

Nanolithography 

P.I-34 Ultrasonic Nanolithography on Hard Substrates 

M. T. Cuberes 

P.I-35 Silicon nanowire transistors with a channel width of 4 nm fabricated by atomic force 

microscope nanolithography 

J. Martinez, R. V. Martinez, R. Garcia 

P.I-36 Contacting self-ordered molecular wires by nanostencil lithography 

L. Gross, R. R. Schlittler, G. Meyer, Th. Glatzel, S. Kawai, S. Koch, E. Meyer 

24

POSTER Session II (Wednesday) 

Molecules 

25 

Chair: Y. Sugawara 

P.II-01 Molecular Structures of Organic Single Crystals Investigated by Frequency Modulation 

Atomic Force Microscopes 

T. Minato, H. Aoki, T. Wagner, K. Itaya 

P.II-02 Imaging of aromatic molecules by tuning-fork based LT-NC-AFM 

B. Such, Th. Glatzel, S. Kawai, S. Koch, A. Baratoff, E. Meyer, C. H. M. Amijs, P. de 

Mendoza, A. M. Echavarren 

P.II-03 One and Two Dimensional Structure of Water on Cu(110) and O/Cu(110)-(2x1) Surface 

B. Y. Choi, Y. Shi, T. Duden, M. Salmeron 

P.II-04 Dynamical simulations of truxene molecules adsorbed on the KBr (001) surface 

T. Trevethan, A. Shluger 

P.II-05 Temperature-dependent growth of C60 on CaF2(111) 

F. Loske, P. Maaß, J. Schütte, A. Kühnle 

P.II-06 Creating 1D nanostructures: Heptahelicene-carboxylic acid on Calcite 

P. Rahe, M. Nimmrich, J. Schütte, I. G. Stara, A. Kühnle 

P.II-07 Atomic Force Microscopy Study of Cross-Linked C32H66 Monolayer by Low-Energy (10eV) 

Hyperthermal Bombardment 

Y. Liu, H.Y. Nie, D.Q. Yang, M.W. Lau, J. Yang 

P.II-08 Towards a molecule-based Ferroelectric-OFET: surface modification of PZT mediated 

through functionalized thiophene derivates 

P. Milde, K. Haubner, E. Jaehne, D. Köhler, U. Zerweck, L. M. Eng 

P.II-09 Imaging and Detection of Single Molecule Recognition Events on Organic Semiconductor 

Surfaces 

N. S. Losilla, J. Preiner, A. Ebner, P. Annibale, F. Biscarini, R. Garcia, P. Hinterdorfer 

P.II-10 Transverse conductance image of DNA probed by current-feedback noncontact AFM 

T. Matsumoto, Y. Maeda, T. Kawai 

P.II-11 Imaging Schwann Cell NGF Receptors using Atomic Force Microscopy 

R. Williamson, Cheryl Miller 

Liquids 

P.II-12 Comparative Studies on Water Structures on Hydrophilic and Hydrophobic Surfaces by 

FM-AFM 

K. Suzuki, N. Oyabu, K. Kobayashi, K. Matsushige, H. Yamada 

P.II-13 Molecular Resolution Investigation of Lysozyme Crystal in Liquid by Frequency-Modulation 

AFM 

K. Nagashima, M. Abe, S. Morita, N. Oyabu, K. Kobayashi, H. Yamada, R. Murai, H. 

Adachi, K. Takano, H. Matsumura, S. Murakami, T. Inoue, Y. Mori, M. Ohta, R. Kokawa 

P.II-14 Noncontact Atomic Force Microscope Observation of TiO2(110) Surface in Pure Water 

A. Sasahara, Y. Jeong, M. Tomitori 

P.II-15 Development of Multifrequency High-speed NC-AFM in Liquid 

Y. J. Li, K. Takahashi, N. Kobayashi, Y. Naitoh, M. Kageshima, Y. Sugawara

Poster Session II cont. (Wednesday) 

P.II-16 Frequency-Domain and Time-Domain Analyses of Soft-Matter Dynamics Using Wide-Band 

Magnetic Excitation AFM 

M. Kageshima, T. Ogawa, S. Kurachi, Y. Naitoh, Y. J. Li, Y. Sugawara 

P.II-17 Noncontact observation in liquid with van der Pol-type FM-AFM 

M. Kuroda, H. Yabuno, T. Someya, R. Kokawa, M. Ohta 

P.II-18 Development of a NC – AFM for Ambient and Liquid Environments 

H. I. Rasool, S. Sharma, J. K. Gimzewski 

P.II-19 Cantilever Holder Design for Spurious-Free Cantilever Excitation in Liquid by Piezoactuator 

H. Asakawa, T. Fukuma 

Oxides and Insulators 

P.II-20 The different faces of the calcite (10-14) surface 

J. Schütte, L. Tröger, P. Rahe, R. Bechstein, A. Kühnle 

P.II-21 Manipulation Mechanism of Single Cu Atoms on Cu(110)-O Surface with Low Temperature 

Non-Contact AFM 

Y. Kinoshita, T. Satoh, Y. J. Li, Y. Naitoh, M. Kageshima, Y. Sugawara 

P.II-22 Simultaneous NC-AFM/STM Imaging of the Surface Oxide Layer on Cu(100) and 

Identification of Lattice Sites 

M. Z. Baykara, T. C. Schwendemann, E. I. Altman, U. D. Schwarz 

P.II-23 nc-AFM Investigations of Metal Nanoclusters on α-alumina 

K. Venkataramani, M. C. R. Jensen, M. Reichling, F. Besenbacher, J. V. Lauritsen 

P.II-24 Atom-resolved AFM studies of the polar MgAl2O4 (001) surface 

M. K. Rasmussen, J. V. Lauritsen, F. Besenbacher 

P.II-25 Contrast formation on cross-linked (1x2) reconstructed titania (110) 

H. H. Pieper, S. Torbrügge, S. Bahr, K. Venkataramani, A. Kühnle, M. Reichling 

P.II-26 Nano volcanoes – the surface structure of antimony-doped TiO2(110) 

R. Bechstein, M. Kitta, J. Schütte, H. Onishi, A. Kühnle 

Electronic and Magnetic Properties 

P.II-27 Non-contact scanning nonlinear dielectric microscopy imaging of TiO2 (110) surfaces 

N. Kin, Y. Cho 

P.II-28 Characterizations of Carbon Material by Non-contact Scanning Non-linear Dielectric 


S. Kobayashi, Y. Cho 

P.II-29 Local Dielectric Spectroscopy of Nanocomposite Materials Interfaces 

M. Labardi, D. Prevosto, S. Capaccioli, M. Lucchesi, P.A. Rolla 

P.II-30 Probing Local Bias-Induced Phase Transitions on the Single Defect Level: from Imaging to 

Deterministic Mechanisms 

N. Balke, S. Jesse, P. Maksymovych, Y.H. Chu, R. Ramesh, S. Choudhury, L.Q. Chen, 

S.V. Kalinin 

P.II-31 Polarization-dependent electron tunneling into ferroelectric surfaces 

P. Maksymovych, S. Jesse, P. Yu, R. Ramesh, A. P. Baddorf, S. V. Kalinin 

P.II-32 Local ferroelectric and magnetic investigations on multiferroic thin films 

U. Zerweck, D. Köhler, P. Milde, Ch. Loppacher, S. Geprägs, S.T.B. Goennenwein, R. 

Gross, L.M. Eng 

26

Poster Session II cont. (Wednesday) 

P.II-33 Magnetic Resonance Force Microscopy in Anisotropic Systems 

T. Fan, V. I. Tsifrinovich 

P.II-34 Sub-10 nm resolution in Magnetic Force Microscopy (MFM) at ambient conditions 

Ö. Karcı, H. Atalan, M. Dede, Ü. Çelik, A.Oral 

P.II-35 Enhancement of the Exchange-bias Effect based on Quantitative Magnetic Force 

Microscopy Results 

N. Pilet, M.A. Marioni, S. Romer, N. Joshi, S. Özer, H.J. Hug 

27

Oral 

Presentations 

Monday, 10 August 

28

Non-retarded and retarded interactions between dielectric cylinders 

Mo-0900 

R. Podgornik 1,2 , Antonio Šiber 3 , Rick Rajter 4 , Roger H. French 5 , W.Y. Ching 6 , and V. 

Adrian Parsegian 2 

1 Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia and Department 

of Theoretical Physics, J. Stefan Institute, SI-1000 Ljubljana, Slovenia 

2 Laboratory of Physical and Structural Biology, NICHD, National Institutes of Health, Bldg. 9, 

Room 1E116, Bethesda, Maryland 20892-0924, USA. 

3 Institute of Physics, P.O. Box 304, 10001 Zagreb, Croatia 

4 Department of Materials Science and Engineering, Massachusetts Institute of Technology, Room 13- 

5046 Cambridge, Massachusetts 02139, USA 

5 DuPont Co. Central Research, Experimental Station, E400-5207 Wilmington, Delaware 19880, USA 

6 Department of Physics, University of Missouri-Kansas City, Kansas City, Missouri, 64110, USA 

I will present a complete theory of non-retarded and retarded van der Waals 

interactions between dielectric cylinders. It is based on the Lifshitz formulation of the 

interactions between two anisotropic semiinfinite media as was worked out by Yu. 

Barash [1] in the complete retarded case. One then recasts the two semiinfinite media 

problem into two anisotropic cylinders problem by expanding the dielectric response 

function as a function of the density of the dielectric cylinders that constitute the two 

media. The first order in the density expansion yields the semiinfinite plane-cylinder 

interaction and the second order term the cylinder-cylinder interaction. Explicit formulae 

are obtained for this interaction and the interaction is evaluated for different examples of 

ab initio carbon nanotube dielectric response functions. The non-retarded case has 

already been discussed in our previous publications [2,3]. I will thus concentrate on the 

features of the van der Waals interaction that are introduced by the retardation and 

orientation effects. 

[1] Yu. S. Barash, Izv. Vyssh. Uchebn. Zaved. Radiofiz. 21 163 (1978). J. N. Munday, D. Iannuzzi, Y. 

Barash and F. Capasso, Phys. Rev. A 71, 042102 (2005). Erratum of the paper J. N. Munday, D. 

Iannuzzi, Y. Barash and F. Capasso, Phys. Rev. A 71, 042102 (2005). 

[2] Rick F. Rajter, Rudi Podgornik, V. Adrian Parsegian, Roger H. French, and W. Y. Ching: van der 

Waals-London dispersion interactions for optically anisotropic cylinders: Metallic and 

semiconducting single-wall carbon nanotubes, Phys. Rev B 76, 045417 (2007). 

[3] Rick Rajter, Roger H. French, Rudi Podgornik, W. Y. Ching, and V. Adrian Parsegian, Spectral mixing 

formulations for van der Waals–London dispersion interactions between multicomponent carbon 

nanotubes, Journal of Applied Physucs 104, 053513 (2008). 

29

Noah Graham 1 

Casimir Forces from Scattering Theory 

1 Department of Physics, Middlebury College, Middlebury, VT USA 

Mo-0930 

Because the parallel-plate geometry of Casimir's original calculation is one of the most 

difficult configurations in which to study the Casimir force experimentally, it is important 

to be able to extend this calculation to other situations. I will describe a general set of 

techniques that allow one to obtain precise theoretical predictions of the Casimir force for 

a wide range of geometries and materials. It applies to any situation where the scattering 

matrix of each individual object can be calculated (or measured), in any basis for which 

the decomposition of a plane wave is known. Although this approach is simplest at large 

distances, it also yields precise results at any separation, as long as the objects do not 

overlap in the radial coordinates of the bases used for each object. In addition to the 

usual situation where the objects are outside of each other, these results extend to the case 

of one object inside another. 

The work I will report on has been done in collaboration with Thorsten Emig 

(Paris/Cologne) Robert L. Jaffe (MIT), Mehran Kardar (MIT), S. Jamal Rahi (MIT), and 

Saad Zaheer (MIT). 

30

Mo-0955 

Multiple Scattering Casimir Force Calculations between Layered and 

Corrugated Materials 

Kimball A. Milton 1 , Inés Cavero-Peláez 2 , Prachi Parashar 1 , K.V. Shajesh 3 , 

and Jef Wagner 1 

1 H.L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019, USA 

2 Laboratoire Kastler Brossel, Université Pierre et Marie Curie, F-75252 Paris, France 

3 St Edward's School, Vero Beach, FL 32963, USA 

Multiple scattering methods have recently proven useful in calculating quantum vacuum 

forces between distinct bodies. In fact, 40 years ago such an approach was used to derive 

the Lifshitz formula for the force between parallel dielectric slabs. More generally, 

numerical results can be readily obtained in many cases, but more remarkably, for weak 

coupling (e.g., for dilute dielectrics), closed-form exact expressions can be derived, 

reflecting the summation of Casimir-Polder forces or their analogues. We have recently 

used such methods to derive forces between corrugated planar and cylindrical surfaces. 

(See Fig. 1.) For scalar fields with Dirichlet boundary conditions, the forces can be 

computed perturbatively in the corrugation amplitudes; 4 th order perturbative results 

agree closely with the exact results for weak coupling. We are now extending such 

calculations to electromagnetism and to general multilayered surfaces (see Fig. 2), where 

again exact results can be obtained in many cases. These results will have important 

applications to experimentally accessible situations, and to nanomachinery. The 

extension to finite temperature will be explored in the near future. 

Fig. 1 Fig. 2 

Figure 1: Concentric corrugated gears. The corrugations have equal spatial frequency. The stable 

equilibrium configuration occurs when the outer troughs align with the inner peaks. If the gears 

are misaligned, a torque is exerted on one cylinder due to the other. 

Figure 2: Multilayered surface. The Casimir energy between two such layered potentials can be 

calculated in closed form. 

31

Drude corrections to Casimir force calculations in liquids 

Raul Esquivel-Sirvent 1 

1 Instituto de Física, Universidad Nacioanl Autónoma de México, México D.F. 01000. 

Mo-1050 

The Casimir force for metals immersed in different fluids has been measured recently 

[1,2,3]. The comparison with theory is based on the Lifshitz formula and the knowledge 

of the dielectric function of the involved materials. In the case of the reported 

experiments, Au is a common metal used in the force measurements. The data for the 

dielectric function of Au can be obtained from tabulated data with a low frequency 

interpolation using the Drude model. The data for the optical properties of Au are usually 

measured in air or partial vacuum. However, changes in the Drude parameters of metals 

when immersed in fluids have been reported in the literature. Gugger [4] using the 

method of total attenuated internal reflection measured the dielectric function of Ag films 

in contact with different liquids. The measurements showed a change in the dielectric 

function of the Ag film depending on the index of refraction of the fluids. The same 

conclusion was reached in the work of Chen [5] that by means of spectroscopic 

ellipsometry measured the Drude parameters for Au and Ag films immersed in liquids, 

confirming the change in the Drude parameters of the metals. 

In this paper we examine the change in the Casimir force between two Au surfaces 

immersed in different fluids and how the change in the Drude parameters affects the 

Casimir force calculations. In particular, we show that variations of the order of 8% are 

possible and observed discrepancies between theory and experiment can be explained 

by this effect. The change of the Drude parameters of a metal immersed in a fluid are 

described by a Bruggeman effective medium theory. Finally, we discuss the possible 

applications of effective medium theories within the Lifshitz formalism. 

[1] J. N. Munday and F. Capasso, Phys. Rev. A 75, 060102(R) (2007). 

[2] J. N. Munday, F. Capasso, V. A. Parseguian and S. M. Bezrukov, Phys. Rev. A 78, 

029906 (2008). 

[3] P. J. van Zwol, G. Palasantzas and J. Th. M. De Hosson, Phys. Rev. B 79, 195428 

(2009). 

[4] H. Guger, M. Jurich and J. D. Swalen, Phys. Rev. B 30, 4189 (1984). 

[5] L. Y. Chen and D. W. Lynch, Phys. Rev. B 36, 1425 (1987). 

32

Diego Dalvit 1 

Dispersive Casimir interactions between atoms and surfaces 

1 Theoretical Devision, MS B213 , Los Alamos National Laboratory, Los Alamos, NM 87545, USA. 

Mo-1115 

Casimir atom-surface interactions may be important in experiments involving atoms in 

proximity to surfaces, such as atom chips for quantum information processing. In this talk 

I will review a general scattering approach to Casimir atom-surface forces, and give some 

examples of its utility in the calculation of non-trivial geometrical effects of the quantum 

vacuum, such as lateral Casimir-Polder forces. I will then briefly describe two proposals 

to use Bose-Einstein condensates (BEC) to probe lateral Casimir forces for atoms above 

corrugated surfaces: a "BEC cantilever" sensitive to gradients of the atom-surface force, 

and BEC Bragg spectroscopy directly sensitive to the atom-surface potential. 

33

Mo-1140 

Van der Waals with a twist: how nanotube chirality impacts interaction 

Rick F. Rajter 1 

strength. 

1Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, 

MA, USA 

The van der Waals - London dispersion interaction depends on the geometries and optical 

properties of all materials or components present within a given system. The ongoing 

investigation of the material property contribution to this interaction continues to yield 

novel and sometimes surprising phenomenon. A chronological review of these 

developments helps underline the importance of material property thinking and why these 

effects must be considered. When first discovered, the differences in interaction strength 

were largely attributed to variations in atomic composition, such as that between various 

noble gases. Once Lifshitz quantified the connection of interaction strength to the 

system’s optical properties, differences in said interactions were also predicted and 

confirmed for allotropes. Perhaps the most obvious example is that of carbon, which can 

take the form of diamond, graphite, graphene, nanotubes, buckyballs, ribbons, etc. Here, 

it was the bond type that was the differentiating factor. The most recent discovery was 

that bond twisting or bending within a given allotrope (i.e. carbon nanotubes) could lead 

to equally dramatic changes. One of the unique features of carbon nanotubes is that a 

very small change in the chirality or twist can greatly change the electronic structure 

properties, which are the key determining factor a material's optical properties. This 

work will show many examples of chirality-dependent optical properties and how this 

information can be used to create experiments to exploit these differences for a variety of 

applications. 

34

Using Casimir and capillary forces to model adhesion of MEMS 

cantilevers 

Maarten P. de Boer 1 and Frank W. DelRio 2 

1 MEMS Technology Dept. Sandia National Laboratories, Albuquerque, NM, USA 

2 National Institute of Standards and Technology, Gaithersburg, MD, USA 

Mo-1205 

Long-range Casimir forces set the lower limit of unwanted adhesion of microscale 

cantilevers to a substrate [1]. To quantify this adhesion, we measure deflections of 

actuated MEMS cantilevers (Fig. 1) by interferometry (Fig. 2), and compare to an 

energy-release rate model. To understand the values, we develop a detailed model of the 

interface including surface roughness, contact mechanics and dispersion forces. We find 

that when surface roughness is less than 3 nm root mean square, the dispersion forces 

dominate adhesion. As surface roughness increases, the real area of contact dominates. 

Agreement between theory and model is within ± 20% when correlations between the 

upper and lower surfaces are taken into account [2]. Adhesion due to capillary forces is 

much greater than that from van der Waals forces. In that case, constitutive laws that 

incorporate disjoining pressure are needed to explain these very high values [3]. Linking 

single asperity models to rough surface models will further develop our understanding in 

these areas. 

Fig. 1 Cantilever adhesion geometry Fig. 2 Interferograms of microcantilevers 

References: 

[1] F. W. DelRio, M. P. de Boer, J. A. Knapp, E. D. Reedy, P. J. Clews and M. L. Dunn, “The role of van 

der Waals forces in adhesion of micromachined surfaces”, Nature Materials, 4 629 (2005). 

[2] F. W. DelRio, M. L. Dunn, L. M. Phinney, C. J. Bourdon and M. P. de Boer, “Rough surface adhesion 

in the presence of capillary adhesion”, Applied Physics Letters, 90 163104 (2007). 

[3] F. W. DelRio, M. L. Dunn and M. P. de Boer, “Capillary adhesion model for contacting 

micromachined surfaces. Scripta Materialia, (2008). 

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin 

Company, for the United States Department of Energy’s National Nuclear Security Administration 

under contract DE-AC04-94AL85000. 

35

Measuring “Virtual Photon” Forces with “Real Photon” Forces 

Hong X. Tang 

Department of Electrical Engineering, Yale University, New Haven, USA 

Mo-1430 

We present an integrated, all-optical nanomechanical device platform to study Casimir 

effect. A versatile optical force 1,2 arising from guided lightwaves (or real photons) 

structure is harnessed to provide accurate counter measure of the Casimir force (the force 

arising from virtual photons). This optical NEMS platform eliminates the electrical 

connections to the devices. The interacting surface can be insulator, semiconducting or 

metallic. The residual potential problem, which has been recently identified to be a major 

source of errors in Casimir measurement, is circumvented by fabricating an electrical link 

between two interacting surface to null out contact potentials and trapped charges. 

c) 

Si Si 

a) 

b) 

c) 

si 

metal metal si 

actuator 

Metal 

Metal 

sensor 

Figures: All-optical schemes for on-chip measurement of Casimir forces. Figure 1: Repulsive optical force 

is used to counter the attractive Casimir force between two silicon beams. Figure 2: Optical force is used to 

balance the Casimir force between two metal beams. 

[1] Mo Li , W. Pernice, C. Xiong, T. Baehr-Jones, M. Hochberg, H. Tang , “Harnessing optical forces in 

integrated photonic circuits.”, Nature , 456, 480(2008) 

[2] M. Li. W. Pernice, H. Tang, “Tunable bipolar interactions between guided lightwaves” Nature 

Photonics (under review, 2009), see also: arxiv:0903.5117 

36

Near-field radiative heat transfer 

Mo-1455 

Alessandro Siria 1, 2 , Emmanuel Rousseau 3 , Jean-Jacques Greffet 3 and Joel Chevrier 1 

1 Institut Néel, CNRS and Université Joseph Fourier, 38042 Grenoble France 

2 CEA-LETI/MINATEC, 17 avenue des Martyrs 38042 Grenoble France 

3 Laboratoire Charles Fabry de L’Institut d’Optique, CNRS UMR, 91127 Palaiseau France 

Near-field force and energy exchange between two objects due to quantum and thermal 

induced electrodynamic fluctuations give rise to interesting phenomena, such as Casimir 

force and thermal radiative transfer exceeding Plank’s theory of blackbody radiation. A 

theoretical explanation, in the framework of stochastic electrodynamics introduced by 

Rytov [1] in the late sixties, accounts for quantum and thermodynamic fluctuations. This 

theory has been successfully applied to model Casimir forces [2] and radiative heat 

transfer [3]. While Casimir force has its origin in quantum fluctuations, related to zero 

point energy, near-field radiative heat transfer is only due to classical thermodynamics 

fluctuations. 

Although significant progresses have been made in the past on the precise measurement 

of the Casimir force [4, 5], a detailed quantitative comparison between theory and 

experiments in the nanometer regime is still lacking when speaking about heat transfer. 

Here, we report experimental data on the thermal flux spatial dependence. Theory based 

on the Derjaguin approximation, is successfully used here for the first time to describe 

radiative heat transfer from the far field to the near field regimes. It reproduces the 

measured dependence with an agreement better than 4 % for gaps varying between 40 nm 

and 5 μm. 

[1] Rytov, S.M., Kratsov, Yu.A., Tatarskii, V.I. Principles of statistical Radiophysics, vol 

3, Springer-Verlag, New-York, (1987) (Chapter 3) 

[2] Lifshitz, E. M. The theory of molecuar attractive forces between solids. Zh. Eksp. 

Teor. Fiz. 29, 94 (1955) [Sov. Phys. JETP 2, 73 (1956)]. 

[3] A. V. Shchegrov, K. Joulain, R. Carminati, and J.-J. Greffet, Phys. Rev. Lett. 85, 1548 (2000) 

[4] U. Mohideen and A. Roy, Physical Review Letters 81, 4549 (1998) 

[5] G. Jourdan, A. Lambrecht, F. Comin, and J. Chevrier, EPL 85, 3, 31001 (2009) 

37

Near-field radiative transfer measurements and implications for 

Casimir force measurements 

Arvind Narayanaswamy 1 , Sheng Shen 2 , Ning Gu 3 , and Gang Chen 2 

1 Department of Mechanical Engineering, Columbia University, New York, USA 

2 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, USA 

1 Department of Electrical Engineering, Columbia University, New York, USA 

Mo-1520 

Near–field force and energy exchange between two objects due to quantum electrodynamic 

fluctuations give rise to interesting phenomena such as Casimir and van der Waals forces, 

and thermal radiative transfer exceeding Planck’s theory of blackbody radiation. Although 

significant progress has been made in the past on the precise measurement of Casimir force 

related to zero-point energy, experimental demonstration of near-field enhancement of 

radiative heat transfer is difficult. In this work, we present a sensitive technique of measuring 

near–field radiative transfer between a microsphere and a substrate using a bi–material 

atomic force microscope (AFM) cantilever, resulting in “heat transfer-distance” curves. 

Measurements of radiative transfer between a sphere and a flat substrate show the presence of 

strong near–field effects resulting in enhancement of heat transfer over the predictions of the 

Planck blackbody radiation theory. We have been able to identify unambiguously the 

contribution of electromagnetic surface phonon polaritons to near-field radiative transfer. The 

implications of measurement of near-field radiative heat transfer for determining of the 

magnitude of the thermal component of the Casimir force will be discussed. 

38

Mo-1615 

Tricks and facts in a high precision measurement of the Casimir force 

with transparent conductors 

S. de Man 1 , K. Heeck 1 , R. J. Wijngaarden 1 and D. Iannuzzi 1 

1 Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, The Netherlands 

The most promising and simple tool to tailor the Casimir force is to alter the behavior of 

quantum fluctuations by properly choosing the materials on the interacting surfaces. 

According to the Lifshitz theory, the interaction between two objects depends on their 

dielectric functions. Transparent dielectrics, for example, attract less than reflective 

mirrors. Unfortunately, transparent dielectrics are prone to charge accumulation. Even a 

small amount of charges can give rise to electrostatic forces that easily overcome the 

Casimir attraction. For this reason, most of the Casimir force experiments reported so far 

have been limited to the investigation of surfaces coated with metal. In that case, 

however, there is not much room to tune the interaction strength, because the diversity in 

the dielectric functions of different metals is simply not large enough. 

In this paper we present a precise experiment where we have investigated the Casimir 

force between a gold coated sphere and a glass plate coated with either a thick gold layer 

or a highly conductive, transparent oxide film [1]. The measurements were performed in 

air, and no electrostatic force due to residual charges was observed over several weeks in 

either case. The decrease of the Casimir force due to the different dielectric properties of 

the reflective gold layer and the transparent oxide film resulted to be as high as 40%− 

50% at all explored separations (from 50 to 150 nm), the largest modification of the 

Casimir force ever observed at ambient conditions. 

In my talk, I will review the new experimental technique we have developed to 

simultaneously (i) calibrate the absolute separation between the two surfaces and the 

force sensitivity of the setup, (ii) compensate for and measure the contact potential, and 

(iii) measure the Casimir force. I will comment on the behavior of the contact potential as 

a function of both absolute surface separation and time. I will also address the issues 

related to mechanical drifts, and how we are able to control those down to a level of 1 

nm/hour [2]. Finally, I will discuss how our experimental technique allows us to double 

check the electrostatic calibration procedure by investigating the hydrodynamic force that 

arises from the cushion of air between the two interacting surfaces [1]. 

[1] S. de Man, K. Heeck, R. J. Wijngaarden, and D. Iannuzzi. arXiv:0901.3720 (2009) 

[2] S. de Man, K. Heeck, and D. Iannuzzi. Phys Rev A 79, 024102 (2009) 

39

Mo-1640 

Measurements of the Casimir force gradient by AFM for Different 

Materials 

Gauthier Torricelli 1 , Stuart Thornton 1 , and Chris Binns 1 

1 Department of Physics and Astronomy, University of Leicester, UK. 

We present here quantitative measurements of the Casimir force gradient in the 50-600 

nm range using a commercial Atomic Force Microscope operating in UHV (VT AFM 

Omicron). The measurements were done in the sphere-plate geometry between a Au 

sphere and plates consisting of three different classes of materials, that is a metal (Au), a 

semimetal (HOPG) and a quasicrystal (AlPdMn). The variation in the optical properties 

of the materials produces clearly observed differences in the Casimir force as predicted 

by calculations using the Lifshitz formula. We will discuss in detail the method of our 

measurements, for which some of the key points are listed below: 

• The calibration of the system is performed using the electrostatic interaction 

without any contact between the sphere and the surface. 

• The electrostatic interaction is also used to verify the stability of our 

measurements notably if there is any variation of the contact potential. 

• A feedback loop is used between two acquisitions in order to prevent any 

changes in the distance separation which can be induce by thermal drift 

• Several measurements are performed in different area of the sample in order to 

test the reproducibility of the measurement. 

40

Measuring the topological dependence of the Casimir force on 

nanostructured silicon surfaces 

Mo-1705 

Ho Bun Chan 1 , Y. Bao 1 , J. Zou 1 , R. A. Cirelli 2 , F. Klemens 2 , W. M. Mansfield 2 , and C. 

S. Pai 2 

1 Department of Physics, University of Florida, Florida, USA 

2 Bell Laboratories, Lucent Technologies, New Jersey, USA. 

The Casimir force is usually regarded as an extension of the van der Waals (vdW) 

interaction between molecules in the retarded limit. By dividing two solid plates into 

small elementary constituents and summing up the vdW force, it is possible to recover 

the distance dependence of the Casimir force between them. For smooth curved surfaces, 

the Casimir force is often calculated using the proximity force approximation (PFA) 

when the separation is small. However, the PFA breaks down when the deformation is 

strong. In fact, one important characteristic of the Casimir force is its strong dependence 

on geometry. The Casimir energy for a conducting spherical shell or a rectangular box 

has been calculated to have opposite sign to parallel plates. Whether such geometries 

exhibit repulsive Casimir forces remains a topic of current interest. 

We performed an experiment to demonstrate the strong geometry dependence of the 

Casimir force [1]. The interaction between a gold sphere and a silicon surface with an 

array of nanoscale, rectangular corrugations is measured using a micromechanical 

torsional oscillator. Deviation of up to 20% from PFA is observed. The data will be 

compared to recent theories on strongly deformed surfaces. In particular, the interplay 

between finite conductivity corrections and geometry effects complicates the comparison 

of data with theories. Ongoing efforts on shallow corrugations will also be presented. 

a) b) c) 

Figure 1: (a) Cross section of the nanoscale rectangular trenches on a silicon surface. (b) 

Schematic of the experimental setup (not to scale) including the micromechanical torsional 

oscillator, gold spheres and silicon trench array. (c) Ratio ρ of the measured Casimir force 

gradient to the force gradient expected from PFA, for two samples with trench arrays with 

different periodicity. The lines represent calculations based on perfect conductors 

[1] H. B. Chan, Y. Bai, J. Zou, R. A. Cirelli, F. Klemens, W. M. Mansfiled and C. S. Pai, Phys. Rev. Lett. 

100, 030401 (2008). 

41

Mo-1730 

Short range Casimir force measurements under ambient conditions and 

liquid environments 

P.J. van Zwol 1 , V.B. Svetovoy 2 , G. Palasantzas 1 , J. Th. M. De Hosson 1 

1 Materials Innovation Institute and Zernike Institute for Advanced Materials 

University of Groningen, 9747 AG Groningen, The Netherlands 

2 MESA_Research Institute, University of Twente, PO 217, 7500 AE Enschede, The Netherlands 

We briefly review ellipsometry [1] and our force measurement in the sphere plane 

geometry [2,3] on smooth and rough gold surfaces, and focus specifically on the contact 

point between rough surfaces, and the optical quality of the surfaces in use. Furthermore 

we outline inverse colloid probe force measurements [4] in liquid environment (fig 1), for 

which we found local charge variation of glass spheres resulting in varying strengths of 

the electrical double layer. In addition we show that when the dielectric function of the 

liquid becomes comparable to that of the surfaces, resulting Casimir forces are very 

small. However sample dependence and uncertainty in the measured dielectric functions 

indicate that the theory is even more uncertain than the measurements, even if measured 

dielectric data is available, for all materials, over all relevant frequency ranges. In the 

extreme limit this can lead to the weird situation that small variations in the dielectric 

data can lead to a complete change of shape of the force, flipping between atractive and 

repulsive, and multiple atractive-repulsive transitions with distance. 

Figure 1: Optical image of sintered borisilicate glass spheres on glass. 

[1] V. B. Svetovoy, P.J. van Zwol, G. Palasantzas, J. Th. M. DeHosson, Phys. Rev. B 77, 035439 (2008) 

[2] P.J. van Zwol, G. Palasantzas, J. Th. M. DeHosson, Phys. Rev. B 77, 075412 (2008) 

[3] P.J. van Zwol, G. Palasantzas, M. van de Schootbrugge, J. Th. M. De Hosson, Appl. Phys. Lett. 92, 054101 (2008) 

[4] P.J. van Zwol, G. Palasantzas, J. Th. M. DeHosson, To appear in Phys. Rev. E (2009). 

42

Mo-1755 

Contact potential difference (CPD) in a Casimir force measurement: 

How do we deal with it? 

W. J. Kim 1 , A. Sushkov 1 , D. A. R. Dalvit 2 , S. K. Lamoreaux 1 

1 P. O. Box 208120, Department of Physics, Yale University, New Haven, CT 06510-8120 

2 Theoretical Devision, MS B213 , Los Alamos National Laboratory, Los Alamos, NM 87545, USA 

In order to achieve the minimum force condition for a pair of conducting plates in electric 

force microscopy, one must always apply a non-zero value of electric potential difference 

across the plates. This so-called contact potential difference (CPD) is ubiquitously 

present in all force measurements and poses an enormous challenge for those wishing to 

accomplish precision quantification of a force of non-electrostatic origin, such as van der 

Waals force and Casimir force. 

In this talk, we will briefly review physical origins of CPD and how it has been taken into 

previous analysis of short-range force measurements. We will also discuss CPD in a 

broader context by presenting some of the experimental studies undertaken in other 

subfields in physics that are challenged by the similar surface potential effects including 

gravitational wave missions like LIGO and LISA as well as our recent measurement of 

the Casimir force between Ge plates at Yale. 

43

Oral 

Presentations 

Tuesday, 11 August 

44

3D Scanning Force Microscopy at Solid/Liquid Interface 

Takeshi Fukuma 1,2 and Yasumasa Ueda 1 

1 Frontier Science Organization, Kanazawa University, Kanazawa, Japan 

2 PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan. 

Tu-0920 

The solid/liquid interface inherently has a three-dimensional (3D) extent in XYZ 

directions. This is particularly evident when solvation layers exist at the interface [1]. In 

frequency modulation atomic force microscopy (FM-AFM), a tip is scanned in XY 

directions to produce a 2D height (or Δf ) image having no vertical extent in Z direction. 

Therefore, the information contained in a 2D FM-AFM image is insufficient for 

understanding 3D distribution of solvent molecules interacting with the atoms or 

molecules constituting the solid surface. In an effort to resolve this issue, 3D force 

mapping technique has been proposed, where a number of force curves are measured at 

arrayed XY positions. This, however, results in a considerable increase of imaging time 

and hence has been used mainly in vacuum at low temperatures. 

In this study, we propose a method referred to as “3D scanning force microscopy (3D- 

SFM)”, where a tip is scanned in Z as well as XY directions. While 3D force mapping is 

based on 1D force spectroscopy, 3D-SFM is based on 2D imaging technique. This 

methodological advancement, together with our recent development of high-speed 

scanner and frequency detector, has enabled us to obtain 3D-SFM image of mica/water 

interface in 53 sec (Fig. 1). The atomically-resolved XY and XZ cross-sectional images 

obtained from the 3D-SFM image allow us to correlate the lateral positions of the surface 

atoms with the vertical distribution of the force field. The site-specific Δf vs distance 

curves are obtained from the Z profiles of the 3D-SFM image, revealing the remarkable 

variation of the force profiles depending on the tip positions. The results demonstrate that 

3D-SFM provides diverse information that has not been accessible with conventional 2D 

imaging techniques. 

Figure 1: (a) XY and XZ cross-sectional images and (b) Δf vs distance curves obtained from a 

3D-SFM image of mica/water interface (53 sec / 3D image, 0.82 sec / XZ image, Raw data). 

[1] T. Fukuma, M. J. Higgins and S. P. Jarvis, Biophys. J. 92 (2007) 3603-3609. 

45

Tu-0940 

Anisotropic Hydration of Biological Molecules Visualized by Three- 

Dimensional Scanning Force Microscopy 

Hitoshi Asakawa 1 , Yasumasa Ueda 1 and Takeshi Fukuma 1,2 

1 Frontier Science Organization, Kanazawa University, Japan 

2 PRESTO, JST, Japan 

Hydration of biological molecules has grave impact on important biological processes 

such as membrane fusions and protein activities. However, molecular-scale details of 

local hydration structures have remained to be understood due to the lack of a method 

able to visualize their three-dimensional (3D) distribution at sub-nanometer resolution. In 

order to resolve this issue, we have recently developed a novel technique referred to as 

3D scanning force microscopy (3D-SFM). Combined with frequency modulation atomic 

force microscopy (FM-AFM) in liquid, the method allows us to record 3D volume data of 

frequency shift (Δf ) induced by tip-sample interaction force in less than 1 min. We are 

able to slice the obtained 3D-SFM image in any directions to produce 2D cross-sectional 

Δf images. 

In this study, we have investigated hydration structures formed at the interface between 

a model biological membrane and aqueous solution. A dipalmitoylphosphatidylcholine 

(DPPC) bilayer was formed on a cleaved mica surface as a model biological membrane in 

HEPES buffer solution. The XY cross-sectional Δf image inserted in Fig. 1(a) was 

obtained by slicing the 3D-SFM image near the tip position closest to the membrane 

surface. The image shows the pseudo-hexagonal packing of DPPC molecules. The 

periodic Δf variation corresponding to the DPPC molecule is also found in a crosssectional 

image obtained by slicing the 3D-SFM image with a plane perpendicular to the 

membrane surface (Fig. 1(b)). The image reveals formation of multiple hydration layers 

on the DPPC bilayer. In addition, we found that the first hydration layer shows 

anisotropic distribution around the DPPC headgroups elongated in one direction in a 3D 

space as indicated by the white arrows. The result demonstrates the capability of 3D-SFM 

for visualizing 3D distribution of water molecules interacting with a biological molecule. 

a) b) 

Figure 1: 3D-SFM images of the interface between a DPPC bilayer and HEPES/NaCl (10/100 

mM, pH 7.4) buffer solution. (a) Schematic illustration of a membrane/water interface. Inset: XY 

cross-sectional Δf image, (b) Z cross-sectional Δf image. 

46

Tu-1000 

Experimental and Theoretical Studies on 3D Hydration Structures 

on Muscovite Mica Surfaces in Aqueous Solution 

N. Oyabu 1 , K. Kimura 2 , S. Ido 1 , K. Suzuki 1 , K. Kobayashi 3 T. Imai 4 , and H. Yamada 1 

1 Department of Electronic Science & Engineering, Kyoto University, Japan 

2 Department of Chemistry, Kobe University, Japan 

3 Innovative Collaboration Center (ICC), Kyoto University, Japan 

4 Computational Science Research Program, RIKEN, Japan 

Recent progress in the two-dimensional (2D) frequency shift (Δf) mapping method 

using the high-resolution FM-AFM in liquids allows us to investigate molecular-scale 

hydration structures on various solid surfaces [1]. A precise comparison of the 

experimental data with theoretical calculations of water structures requires the threedimensional 

(3D) Δf mapping method, which can clarify more the relationship between 

the crystal site on the surface and the hydration structure. However, there are several 

difficulties in the 3D-Δf mapping in liquids including a large, linear and nonlinear 

thermal drift of the tip position relative to the surface. 

We have developed a low-thermal-drift FM-AFM working in liquids based on a 

commercial AFM. A sufficiently low, lateral thermal drift rate of less than 1 nm/min was 

achieved in liquids by an accurate temperature control of the environment and by a large 

reduction of the liquid evaporation. We obtained 3D-Δf data on a muscovite mica surface 

in a 1M KCl solution. Figure 1 shows three examples of the 2D-Δf image taken out of the 

3D-Δf data. Figures 2(a) and (b) are constant height (Δf distribution) X-Y images 

reconstructed from the 3D-Δf data. The vertical position (Z) of the plane of Fig. 2(a) is 

about 0.2 nm closer to the surface compared to that of Fig. 2(b). Figures 2(c) and (d) are 

X-Y water density distributions calculated using the 3D reference interaction site model 

(3D-RISM) theory at the corresponding vertical positions, respectively. At each position 

the experimental image agrees well with the calculated density distribution. In addition, 

this 3D-Δf mapping method in liquids has been also applied to the study of hydration 

structures on biomolecules. 

Z1 Z0 Z 

Y 

X 

Figure 1: Three examples of the 2D 

(X-Z)-Δf mapping image taken out of 

the 3D-Δf data (X = 3 nm, Y = 3 nm, Z 

= 3 nm). 

Figure 2: (a), (b) Constant height X-Y images reconstructed from 

the 3D-Δf data at different heights. The Z-position (a) is 0.2 nm 

closer to the surface than the position (b). (c), (d) Water density 

distributions calculated by the 3D-RISM theory at the 

corresponding heights. 

[1] K. Kimura et al., The 11 th International conference on Non-Contact Atomic Force Microscopy, Sept. 

2008, Madrid, Spain, Abstract booklet, p62 

47

Theory of Tip-Sample Interaction Force Mediated by Water 

M.Tsukada 1 , M.Harada 2 , and K.Tagami 2 

1 WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan 

2 Advance Soft Corp. Tokyo, Japan 

Tu-1020 

Noncontact AFM(ncAFM) in liquids is a powerful method for observing nano-scale 

images of soft-materials as protein. We are developing theoretical simulation 

methodologies of ncAFM in liquid[1,2], and by the simulation, we found various 

remarkable features of tip-surface interaction force mediated by water[2]. They are 

obtained either by the molecular dynamics (MD) calculation or by the 3D-RISM 

(Reference Interacting Site Model) calculation. 

As a case study of the MD method, ncAFM images and 3D force map of mica surface 

in water were calculated and compared with the experiments by Yamada’s Group. The 

oscillatory layer structures of water exist around the interface tracing the nano-scale 

shapes of the sample. The phase/amplitude of the force oscillation is changed depending 

on the lateral tip position, and the 3D force map shows a complicated network structure 

of attractive and repulsive regions. The numbers of the water layers in the narrow gap 

decreased abruptly and finally disappears when the tip approaches to the surface. 

The 3D-RISM method was applied to clarify the local charge separation effect on the 

interaction force in water. The distribution of water molecules around the atomically 

charged portion on the substrate is considerably disturbed, and this effect is observed in 

the force map from far region. We discuss how drastically different the water mediated 

tip-sample force compared with that in vacuum, and how they influence on the images. 

a) b) 

Figure 1 a) Simulated force map of mica in water by the MD method, and b) 

The distribution function of water molecules near the flat solid surface. The atom shown 

with red and blue sphere are ionized positively and negatively, respectively. 

[1]M. Tsukada, N. Watanabe, Jpn.J.Appl.Phys., vol.48 No.3 2009 

[2] Tsukada, Tagami , J.Phys.Soc.Jpn., submitted. 

48

Dynamic Force Spectroscopy of Single Chain-like Molecules 

Daniel Ebeling 1 , Harald Fuchs 1 , Filipp Oesterhelt 2 , and Hendrik Hölscher 3 

Tu-1120 

1 

Center for Nanotechnology (CeNTech), Heisenbergstrasse 11, 48149 Münster, Germany and 

Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149 

Münster, Germany 

2 

Institut für Physikalische Chemie II, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 

40225 Düsseldorf, Germany 

3 

Institute for Microstructure Technology (IMT), Forschungszentrum Karlsruhe, P.O. box 36 70, 76021 

Karlsruhe, Germany 

In order to measure forces acting on a single chain-like molecule during a stretching 

experiment in liquid, we introduce a dynamic approach based on the frequencymodulation 

technique with constant-excitation. In difference to the classical approach 

where the force is recorded as a conventional force vs. distance curve in a static 

measurement, we are able to detect simultaneously the conservative force as well as the 

energy dissipation during the elongation of a chain-like molecule. 

Therefore the amplitude and the frequency shift of an oscillating cantilever are measured 

during the retraction from the surface (Fig. 1a and b) [1]. The tip-sample force (Fig. 1c) 

and the energy dissipation (Fig. 1d) can be reconstructed from these data sets via an 

analytical approach. We apply this technique to dextran monomers and demonstrate the 

agreement of the experimental force curves with a ``single-click'' model [2]. 

Figure 1: a) Amplitude and b) frequency shift curves measured during approach to and retraction 

from the surface covered with dextran molecules. c) Force acting on the dextran molecule as a 

function of the actual tip position. The experimental result is well described by a ``single-click'' 

model (solid line) d) Energy dissipation per oscillation cycle. 

[1] D. Ebeling, F. Oesterhelt, H. Hölscher (submitted). 

[2] R. G. Haverkamp, A. T. Marshall, and M. A. K. Williams, Phys. Rev. E 75, 021907 (2007). 

49

Spatial force fields above a single atom defect 

André Schirmeisen 1 and Domenique Weiner 2 

1 CeNTech (Center for Nanotechnology) and Institute of Physics, University of Muenster, Germany 

2 SPECS Zurich GmbH, Switzerland 

Tu-1140 

Atomic force microscopy under ultrahigh vacuum conditions is a powerful tool to 

investigate the atomic structure of surfaces. The method of 3D force field spectroscopy 

[1] allows the spatial analysis of vertical and lateral interatomic forces [2], as well as the 

potential energy landscape with atomic resolution [3]. In this study we focus on the 

analysis of surface defects on a NaCl(001) crystal by 3D force field spectroscopy. The 

spatial force fields along different crystallographic directions were measured above a 

defect, which appeared as a valley of molecular dimensions in the surface topography. 

We find that the vertical tip-sample force directly above the defect is repulsive. From the 

force fields we calculate the atomic scale potential energy landscape, which is compared 

to model calculations. This model is based on electrostatic interactions of hard spheres 

and assumes an ion terminated tip apex. According to this model our experimental 

potential energy fields agree best with a situation where a single ion is missing in the 

surface. This raises interesting questions about the unexpected stability of single charge 

defects in an ionic surface. 

Figure 1: Left: Topography scan of NaCl(001) showing a surface defect. Right: Frequency shift 

slice extracted from 3D spectroscopy data along a row of ions including the surface defect. The 

force and energy profiles best agree with a model assuming a singular missing ion. 

[1] Hölscher, Langkat, Schwarz, Wiesendanger, Appl. Phys. Lett. 81, 4428 (2002) 

[2] Ruschmeier, Schirmeisen, Hoffmann, Phys. Rev. Lett 101, 156102 (2008) 

[3] Schirmeisen, Weiner, Fuchs, Phys. Rev. Lett. 97, 136101 (2006) 

50

Simultaneous measurement of force and tunneling current 

Tu-1200 

Daisuke Sawada, Yoshiaki Sugimoto, Ken-ichi Morita, Masayuki Abe, and Seizo Morita 

Graduate school of Engineering, Osaka University, Osaka, Japan 

We have performed simultaneous STM and AFM measurements in the dynamic mode 

using Pt-Ir coated Si cantilevers at room temperature. Frequency shift (Δf) and timeaverage 

tunneling current () images were obtained by tip scanning on the Si(111)- 

(7×7) surface at constant height mode to prevent a crosstalk between these two channels 

[Fig.1 (a)]. To compensate the thermal drift of the tip-surface distance, feed forward 

technique was applied [1]. Analysis of 25 sets of AFM/STM images using different tips 

shows that when atomic resolution is obtained simultaneously by both AFM and STM, 

the tunneling current is much larger than the typical values in conventional STM. We 

have also performed simultaneous measurements of site-specific force/tunneling 

spectroscopy. The Δf and versus tip-surface distance curves were converted into the 

short-range force (FSR) and the tunneling current (It) at closest separation between the 

sample surface and the oscillating tip [Fig.1 (b)]. We observed the drop in the tunneling 

current due to the chemical interaction between the tip apex atom and the surface adatom, 

which was found recently [2], and estimated the value of the chemical bonding force. 

Furthermore, scanning tunneling spectroscopy (STS) was performed on the same site 

using the same tip [Fig.1 (c)]. The spectrum is in good agreement with previous STM 

results. Our results demonstrate that one can quantitatively measure the local density of 

state and the chemical bonding force above the same atom using the same tip [3]. 

Figure 1: (a) Δf and images of a Si(111)-(7×7) surface simultaneously obtained in the 

constant height mode at room temperature. The acquisition parameters are f0=284092.5 Hz, 

A=300 Å, k=22.9 N/m, and Vs=-400 mV respectively. (b) It-z and FSR-z curves derived from z 

and Δf-z curves obtained above a center adatom in a faulted half unit cell, respectively. (c) STS 

spectrum and Δf - Vs curves obtained at z=4.4 Å. 

[1] M. Abe, et al., Appl. Phys. Lett. 90, 203103 (2007). 

[2] P. Jelinek, M. Svec, P. Pou, R. Perez, and V. Chab, Phys. Rev. Lett. 101, 176101 (2008). 

[3] D. Sawada, Y. Sugimoto, K. Morita, M. Abe, and S. Morita, Appl. Phys. Lett. in press. 

51

Atom Manipulation on Cu(110)-O Surface with LT-AFM 

52 

Tu-1220 

Yasuhiro Sugawara, Yukinori Kinoshita, Yan Jun Li, Yoshitaka Naitoh, and Masami 

Kageshima 

Department of Applied Physics, Osaka University, Suita, Japan 

Manipulation of single atoms and molecules is an innovative experimental technique 

of nanoscience. So far, a scanning tunneling microscopy (STM) has been widely used to 

fabricate artificial structures by laterally pushing, pulling or sliding single atoms and 

molecules. However, the driving forces involved in manipulation have not been 

measured. Recently, an atomic force microscopy (AFM) has been also used to manipulate 

single atoms and molecules. Atom manipulation with an AFM is particularly promising, 

because it allows the direct measurement of the required forces [1]. 

Recently, we investigated the forces in AFM lateral manipulation for a top single Cu 

atom (super Cu atom) on the Cu(110)-O surface. In the case of Cu-adsorbed AFM tip, the 

super Cu atom on the surface was pulled at a lateral tip position on the adjacent binding 

site. In contrast, in the case of O-adsorbed AFM tip, the super Cu atom was pushed over 

the top of the super Cu atom. Thus, we found that the forces (attractive or repulsive 

forces) to move an atom laterally on the surface strongly depend on the atom species of 

the AFM tip apex and the surface. 

In the present study, in order to further clarify the manipulation process depending on 

the chemical nature of tip-sample interaction, we investigate the full tip-sample potential 

landscape necessary to manipulate atoms. 

All experiments were performed by using homebuilt noncontact AFM using frequency 

modulation technique operating in ultrahigh vacuum at a temperature of about 78 K. The 

AFM tip apex was coated with Cu or O atoms in situ by slightly making a tip-sample 

mechanical contact on the Cu(110)-O surface prior to the imaging. The tip-sample 

potentials are determined form the frequency shift versus distance curves by 

mathematical analysis. We found that the tip-sample potentials to move the super Cu 

atom laterally on the surface strongly depend on the atom species of the AFM tip apex 

and the surface. These results strongly suggest that the chemical nature of tip-sample 

interaction plays an important role in lateral atom manipulation. Furthermore, we discuss 

the pathways for moving the super Cu atom. 

Reference 

[1] M. Ternes, C. P. Lutz, C. F. 

Hirjibehedin, F. J. Gissibl and 

Andreas J. Heinrich. Science, 

319, 66 (2008). 

(a) (b) 

Figure 1: AFM images (a) before and (b) after atom 

manipulation performed on Cu(110)-O surface at 78K.

Water, Ions, Membranes, Real Metals, Finite Temperature: 

Is there ever a pure Casimir force? 

Adrian Parsegian 1 

1 National Institutes of Health, Bethesda, MD 20892-0924 

Tu-1430 

The powerful idea of vacuum fluctuations strictly confined between ideal metals 

dominates the psychology of much thinking about electrodynamic forces. In fact, most 

systems reveal interactions that depend on material properties wherein fluctuations 

penetrate unto permeate interacting bodies. This talk will attempt to delineate 

the conditions under which true Casimir forces can be expected as compared with the 

material-based van der Waals forces formulated by Lifshitz, Dzyaloshinskii, and 

Pitaevskii, then generalized by their descendents. 

53

Short and medium range electrostatic forces analyzed by 

Kelvin probe force microscopy 

Th. Glatzel, S. Kawai, S. Koch, A. Baratoff, and E. Meyer 

Department of Physics, University of Basel, 4056 Basel, Switzerland. 

Tu-1510 

We discuss the influences of short and medium range electrostatic forces on the local 

contact potential difference (LCPD) by means of amplitude modulated Kelvin probe 

force microscopy (AM-KPFM) measured on single crystal KBr(100) surfaces. Bias- and 

z-spectroscopic curves at atomic scale showing clear features related to the influence of 

the short range electrostatic interaction [1]. 

In Fig.1 a typical nc-AFM /KPFM measurement of a KBr(100) in UHV is shown. While 

the topography (a) was measured at the first resonance frequency of the cantilever 

(approx 160kHz), the LCPD image (b) was measured by compensating the inphase signal 

detected at he second resonance (approx 1MHz). A clear contrast between the different 

ionic sides is observed. To clarify the origin of this contrast we performed bias- and zspectroscopy 

measurements. c) shows a bias-spectroscopy measurement illustrating the 

amplitude R, the inphase signal X, and the frequency shift at a maxima of the topography. 

Comparing these measurements with the ones at the minimas of the topography (not 

presented here) clearly shows the expected CPD difference. 

Figure 1: Typical topography (3x3nm 2 , �z=100pm) and 

local contact potential image (�LCPD=300mV) of a 

KBr(100) surface. In c) the lockin signals amplitude R, 

inphase X (second resonance of the cantilever) as well as 

the frequency shift of the first resonance �f are plotted 

over the bias voltage applied to the sample. The 

measurement was done at a maxima of the topography. 

[1] F. Bocquet et al., Phys. Rev. B 78, (2008), 035410. 

54

Tu-1530 

The Effective Quality Factor in Dynamic Force Microscopes with 

Fabry-Perot Interferometer Detection 

Hendrik Hölscher 1 , Peter Milde 2 , Ulrich Zerweck 2 , Lukas M. Eng 2 , Regina Hoffmann 3 

1 Institute for Microstructure Technology (IMT), Forschungszentrum Karlsruhe, Karlsruhe, Germany 

2 Institut für Angewandte Photophysik, Technische Universität Dresden, Germany 

3 Physikalisches Institut and DFG-Center for Functional Nanostructures, Universität Karlsruhe, Germany 

Recently, the self-oscillation of microfabricated silicon resonators by photo-induced 

forces has become a focus of current research in order to reach the quantum ground state 

[1]. Having these results in mind, it is interesting to note that the experimental set-up 

used in these studies is similar in design to the standard instrumentation of lowtemperature 

ultra-high vacuum atomic force microscopes (LT-UHV-AFM) using 

interferometer detection [2,3]. 

In order to quantify the relevance of photo-induced forces for NC-AFM 

experiments, we analyzed the oscillation behavior of a microfabricated cantilever in a 

LT-UHV-AFM with a Fabry-Perot interferometer. We observed that photo-induced 

forces depend on the cantilever-fiber distance and that they lead to a profound change of 

the effective quality factor of the cantilever. Depending on the slope of the interference 

signal, the effective quality factor of the cantilever is increased or decreased. The overall 

effect increases with the laser power of the laser diode and decreases for higher 

temperatures. The Q-factor of the cantilever, however, is an essential parameter when the 

energy dissipation between tip and sample is measured with a dynamic force microscope. 

Hence, the effect addressed here has to be taken into account whenever the cantilever 

oscillation is measured with an interferometer at low temperatures. 

a) b) c) 

Figure 1: (a) Schematic set-up of the interferometer used for the detection of the cantilever 

vibration in dynamic force microscopy (b) The resulting interference intensity is periodic and has 

a positive or negative slope. (c) Depending on the slope and the temperature the resonance curves 

change dramatically due to a change of the effective Q-factor of the cantilever. 

[1] C. Höberger-Metzger and K. Karrai, Nature 432, 1002 (2004). 

[2] D. Rugar, H. J. Mamin, and P. Guethner, Appl. Phys. Lett. 55, 2588 (1989). 

[3] A. Moser et al., Meas. Sci. Technol. 4, 769 (1993). 

55

Oral 

Presentations 

Wednesday, 12 August 

56

We-0900 

Imaging Single Atoms on Oxide Surfaces – Gold on Alumina/NiAl(110) 

Markus Heyde, Georg Hermann Simon, Thomas König, and Hans-Joachim Freund 

Fritz-Haber-Institute of the Max-Planck-Society, Faradayweg 4-6, D-14195 Berlin, Germany 

A logical next step after gaining atomic resolution on complex surfaces of wide 

band-gap materials with FM-DFM is the determination and characterization of ad-atom 

adsorption sites on such materials. Imaging metal ad-atoms on complex oxide surfaces 

with atomic resolution is of a certain value in the study of these materials and has not 

been shown before. Here we present recent work on adsorbed gold atoms on the ultrathin 

alumina on NiAl(110) with its large complex surface unit cell as an example. It can be 

shown that an established contrast in FM-DFM [1,2] enables the determination of 

adsorption sites with atomic scale precision. This holds despite the fact that gold is rather 

easily removed by the tip and gives confidence for atomic scale characterisation and 

manipulation of ad-species on oxide surfaces with FM-DFM. Obtained results are 

compared to density functional theory calculations for preferred adsorption sites of gold 

atoms on this alumina film [3]. 

Figure 1: (a) Atomic resolution FM-DFM image of the ultrathin alumina on NiAl(110). The 

large unit cell (here an A domain) is indicated (scan range 4.2 nm × 4.2 nm ). (b) FM-DFM image 

of adsorbed gold atoms on the alumina film (scan range 10 nm × 10 nm). (c) Preferential 

adsorption sites for gold atoms as determined by density functional theory [3]. 

[1] G. H. Simon, T. König, M. Nilius, H.-P. Rust, M. Heyde, and H.-J. Freund; Phys. Rev. B 78 (2008) 

113401. 

[2] G. Kresse, M. Schmid, E. Napetschnig, M. Shishkin, L. Köhler, and P. Varga; Science 308 (2005) 

1440. 

[3] N. Nilius, M.V. Ganduglia-Pirovano, V. Brázdová, M. Kulawik, J. Sauer, and H.-J. Freund; Phys. 

Rev. Lett. 100 (2008) 096802. 

57

Site-specific force spectroscopy on TiO2 (110) surface at lowtemperature 

A. Yurtsever, A. Pratama, Y. Sugimoto, M. Abe, and S. Morita 

Graduate School of Engineering, Osaka University, Osaka, Japan 

We-0920 

Non-contact AFM (nc-AFM) has opened the way for the measurement of the forces 

that are generated between different kinds of interaction on surfaces. Using the homemade 

low temperature nc-AFM, we study the site-specific force spectroscopy on the 

rutile TiO2 (110)-(1x1) metal oxide surface. The rutile TiO2(110) surface has been 

intensively used as a subject of numerous surface science investigations over the years 

due to its wide variety of technological applications such as catalysis, solar cells, surface 

protective coatings, and gas sensing devices for pollution control [1]. In AFM, imaging of 

metal-oxide surfaces, the image contrast strongly depends on the chemical constitution of 

the surface layer and the chemical identity of the tip-apex structure [2]. Depending on the 

polarity of tip-apex charged state, the distinct types of image contrast are observed. In 

order to clarify the imaging mechanism of each contrast modes, we need to perform the 

measurement of force-displacement curves on this surface. By employing the atomtracking 

technique [3], force–distance measurements over three different atomic sites, 

using three different tip states, were obtained. We observe that the maximum attractive 

interaction force is smallest on OH groups for different tip-apex states. In this 

contribution, we will discuss the effect of the different tip terminations on interaction 

force over surface atomic (e.g., Ob, Ti) and defect (e.g., OH) sites. 

Figure 1: Low-temperature atomic force microscopy spectroscopic measurements over various 

sites in the TiO2 (110) surface. The force versus distance data obtained with a neutral tip (e.g., Si) 

(a) and with a positively terminated tip (b). Inset: Shows the corresponding topographic images of 

each contrast modes at the same surface area. 

[1] U. Diebold, Surf. Sci. Rep. 48, 53-229 (2003). 

[2] G. H. Enevoldsen et al., Phys. Rev. B 78, 045416 (2008). 

[3] M. Abe et al., Appl. Phys. Lett. 90, 203103 (2007). 

58

We-0940 

Character of the short-range interaction between a silicon based tip and 

the TiO2(110) surface: a DFT study 

Cesar Gonzalez 1,2 , Pavel Jelínek 1 , and Ruben Pérez 3 

1 

Department of Thin Films, Institute of Physics of the ASCR, Prague, Czech Republic 

2 

Departamento de Superficies y Recubrimientos, Instituto de Ciencia de Materiales de Madrid del CSIC, 

Spain 

3 Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, Spain 

Non-contact atomic force microscopy (NC-AFM) provides a rich variety of atomic 

contrasts on the rutile TiO2 (110) surface, imaging either the bridging oxygen atoms 

(hole mode) or the titanium atoms (protrusion mode) [1]. These contrast modes have been 

assigned to purely electrostatic interaction. Another contrast mode that does not ?t into 

the scheme of purely electrostatic interaction, the so-called neutral mode, has also been 

reported[]. Recently it has been demonstrated that NC-AFM is capable of imaging both, 

the bridging oxygen atoms and the titanium rows simultaneously in a new “all inclusive” 

mode [3]. Such diversity of contrast modes can be attributed to the complex character of 

the short range interaction between tip and characteristic sites of the rutile TiO2 (110) 

surface driven by (i) a weak short-range electrostatic interaction [4] depending on atomic 

termination of tip and its polarization and (ii) the onset of chemical bond formed between 

a tip and surface [5]. A proper characterization of the different regimes in the short-range 

interaction regime Si-based tips and this oxide surface is crucial for the interpretation of 

the experimental images and the design of protocols for single atom manipulation and 

chemical identification. 

Here we have employed density-functional theory (DFT) calculations to understand 

the character of tip-sample interaction between clean and contaminated Si-based tips and 

the TiO2 surface. We have performed a detailed analysis of electronic structure and the 

charge transfer between tip and sample. Our calculations show that the relative 

contribution of the weak short-range electrostatic interaction and the on-set of chemical 

bonding between the closest tip and surface atoms is very sensitive to the tip-sample 

distance, de?ning di? erent interaction regimes along the tip-sample distance. In 

particular, we show the short-range electrostatic interaction in weak interaction regime 

can provide a complex atomic contrast such as the experimentally reported neutral and 

all-inclusive contrast modes. 

[1] J.V. Lauritsen et al., Nanotechnology 17, 3436 (2006). 

[2] G.H. Enevoldsen et al., Phys. Rev. B 78, 045416 (2008). 

[3] R. Bechstein et al (submitted). 

[4] A.S. Foster et al., Phys. Rev. B 68, 195420 (2003). 

[5] R. Pérez et al., Phys, Rev. B 58, 10835 (1998). 

59

We-1000 

True atomic resolution imaging on an application-oriented system: 

Understanding photocatalytic reactivity of transition-metal doped TiO2 

Ralf Bechstein 1,2 , Mitsunori Kitta 3 , Jens Schütte 1 , Hiroshi Onishi 3 , and Angelika Kühnle 1 

1 Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49076 Osnabrück, Germany 

2 present address: iNano, Aarhus University, DK-8000 Aarhus C, Denmark 

3 Department of Chemistry, Kobe University, Rokko-dai, Nada-ku, Kobe 657-8501, Japan. 

The influence of transition-metal dopants, namely chromium and antimony, on the 

surface structure of TiO2(110) was investigated at the atomic level using frequency 

modulation NC-AFM. We found the vacancy density created upon doping to depend 

strongly on the dopant ratio [1, 2], explaining differences in photocatalytic reactivity [3, 

4]. The surface roughness and the arrangement at the atomic scale (see e.g. Fig. 1) gave 

further insight into the implications of doping of titanium dioxide. 

This work demonstrates that NC-AFM is capable of true atomic resolution, even on 

rough and highly corrugated surfaces. Thus, it constitutes a step towards investigating 

more realistic, application-oriented systems using NC-AFM, revealing detailed insights 

into the implications of transition-metal doping on the surface structure of the wide band 

gap photocatalyst titanium dioxide. 

(a) (b) 

Figure 1: NC-AFM detuning images of TiO2(110) codoped with chromium and antimony. 

Enhanced surface roughness is observed (a). At a first glance, the atomic structure of the doped 

surface resembles the structure of pristine TiO2(110) (b). A careful analysis of the high-resolution 

images unravelled a surface reconstruction that closely resembles a (1 x 4) structure, indicating a 

firm integration of the dopant atoms into the titanium dioxide crystal. 

[1] R. Bechstein et al., J. Phys. Chem. C, 113, 3277 (2009). 

[2] R. Bechstein et al., submitted to J. Phys. Chem. C (2009). 

[3] H. Kato and A. Kudo, Catal. Today 78, 561 (2003). 

[4] T. Ikeda et al., J. Phys. Chem. C 112, 1167 (2008). 

60

We-1020 

Local surface photovoltage spectroscopy of molecular clusters using 

Kelvin probe force microscopy 

Sascha Sadewasser, Martha Ch. Lux-Steiner 

Helmholtz Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, 14109 Berlin, Germany 

The high optical absorption properties of organic molecules are of high interest for 

photovoltaic application, as well in purely organic as in dye sensitized solar cells. In the 

latter, the electron conductor is typically a porous TiO2, which is used to enhance the 

surface and contact areas. Investigation of the local optoelectronic properties of such 

molecules and interfaces is of high interest for the understanding of charge separation 

processes and ultimately the improvement of these types of solar cells. 

With the goal to gain access to optoelectronic properties on the nanometer scale, we 

have recently set up a surface photovoltage spectroscopy (SPS) system in combination 

with a Kelvin probe force microscope (KPFM) operated in ultra high vacuum (UHV). 

Sample illumination is realized by a halogen lamp and monochromator in the visible 

spectrum range using an optical fiber introduced into the UHV. Using chopped light and 

lock-in detection the SPV signal can be measured with a sensitivity of better than 1mV. 

For the KPFM operation we use the resonant amplitude modulation technique, which 

allows using a low modulation voltage (~0.1V). 

Here we present a study of various organic molecules used in organic and dye 

sensitized solar cells. For the case of the dye N3, small amounts of molecules were 

deposited onto TiO2 single crystals and subsequently measured by SPS in the UHV- 

KPFM. Fig. 1 shows the topography and work function image of the sample, clearly 

showing a higher work function for the molecule clusters. Spectroscopy in various points 

on the sample shows clearly distinct spectra on the molecules as compared to the TiO2 

surface. The absorption and charge separation of the various molecules will be discussed 

comparatively. 

Figure 1: (a) Topography (800×800 nm 2 ) and (b) corresponding work function image obtained 

by KPFM. The symbols indicate the position of SPV spectra. (c) Averaged SPV spectra taken on 

TiO2 (squares) and on N3 molecule clusters (circles). Clearly the enhanced absorption of N3 in 

the range below ~ 600 nm can be seen. 

61

We-1120 

Why is Graphite so Slippery? Gathering Clues from Three-Dimensional 

Lateral Forces Measurements 

Udo D. Schwarz 1 , Mehmet Z. Baykara 1 , Todd C. Schwendemann 1,2 , Boris J. Albers 1 , 

Nicolas Pilet 1 , and Eric I. Altman 2 

1 

Department of Mechanical Engineering and Center for Research on Interface Structures and Phenomena 

(CRISP), Yale University, New Haven, USA 

2 

Department of Chemical Engineering and Center for Research on Interface Structures and Phenomena 


Conventional lateral force experiments give insufficient insight into the fundamental 

reasons for graphite’s outstanding qualities as a solid lubricant due to an averaging effect 

caused by the finite contact area of the tip with the sample. To overcome this limitation, 

we used a noncontact atomic force microscopy-based approach that enables use of 

atomically sharp tips. The new technique [1], performed using a home-built low 

temperature, ultrahigh vacuum atomic force microscope [2], allows the measurement of 

normal and lateral surface forces in all three dimensions with picometer and piconewton 

resolution. 

In this presentation, we analyze the height and lattice site dependence of lateral forces, 

their dependence on normal load, and the effect of tip shape in detail. The lateral forces 

are found to be heavily concentrated in the hollow sites of the graphite lattice, surrounded 

by a matrix of vanishingly small lateral forces. It will be argued that this astonishing 

localization may be a reason for graphite’s excellent lubrication properties. In addition, 

the distance and load dependence of the lateral forces experienced along possible “escape 

routes” from the hollow sites, which would be followed by a slider that is dragged out of 

them, are studied. Surprisingly, the maximum lateral forces along these escape routes, 

which ultimately determine the static friction, are found to depend linearly on normal 

load, suggesting the validity of Amontons' law in the noncontact regime. 

Figure 1: a) Possible escape routes which would be preferred by a nanoslider as it is dragged 

away from a hollow site. b) Dependence of static friction in direction (I) on normal load. 

[1] B. J. Albers et al., Nature Nanotechnology 4, 307 (2009). 

[2] B. J. Albers et al., Rev. Sci Instrum. 79, 033704 (2008). 

62

We-1140 

Theoretical DFT simulations of the STM/AFM atomic scale imaging on 

graphite. 

Vít Rozsíval 1 , Martin Ondráček 1 , Pavel Jelínek 1 

1 Department of Thin Films, Institute of Physics of the ASCR, Prague, Czech Republic 

Graphite is used as a standard benchmark surface to achieve atomic resolution by 

Scanning Probe Methods (SPM). True atomic scale contrast of graphite provided by 

simultaneous measurement of both forces and tunneling current is still source of 

controversy [1-3]. The hexagonal surface unit cell contains to non-equivalent atoms: the 

α-site atom located directly above adjacent planes and β-site atom above the hollow site. 

While there is a consensus on STM measurements seeing every second, β-site, atom in 

the hexagonal unit cell [4], the situation turns more conflicting in the case of nc-AFM 

experiments. Main doubt arises where the maximum of the contrast is located: (i) over 

hollow site [2] or one C atom [1]; and (ii) if the α and β atoms can be distinguished by 

nc-AFM. 

The direct quantitative interpretation of SPM measurements in the near-to-contact 

mode is a not straightforward task due to several factors playing an important role in 

imaging processes. Realistic conductance calculations have to involve properly several 

effects: e.g. the tip/surface structural relaxations and multiple electron scattering to 

understand properly the relation between forces and currents measured in experiments 

[5]. Here we performed state-of-the-art theoretical studies based on a combination of total 

energy DFT calculations with a Green's function approach for the electron STM transport 

[5] between silicon or tungsten tip and graphite. We analyzed the electronic structure 

evolution along tip-sample distance. In addition, we analyzed the relation between the 

chemical short-range force and the conductance from the tunnelling to the contact 

regime. 

[1] S. Hembacher, F. J. Giessibl, J. Mannhart, and C. F. Quate, PNAS 100, 12539 (2003). 

[2] H. Holscher, W. Allers, U.D. Schwarz, A. Schwarz, and R. Wisendanger Phys. Rev. B 62, 6967 (2000) 

[3] S, Kawai and H. Kawakatsu, Phys. Rev. B 79, 115440 (2009). 

[4] G. Binning et al, Europhys. Lett. 1, 31 (1986). 

[5] P. Jelínek, M. Švec, P. Pou, R. Pérez and V. Cháb, Phys.Rev. Lett. 101 (2008). 

63

We-1200 

Atomic-Resolution Damping Force Spectroscopy on Nanotube Peapods 

with Different Tube Diameters 

M. Ashino 1 , R. Wiesendanger 1 , A. N. Khlobystov 2 , S. Berber 3,4 , and D. Tománek 4 

1 Inst. of Applied Physics & Microstructure Research Center, University of Hamburg, Hamburg, Germany 

2 School of Chemistry, University of Nottingham, Nottingham, UK 

3 Physics Department, Gebze Institute of Technology, Gebze, Turkey 

4 Physics and Astronomy Department, Michigan State University, East Lansing, USA. 

Damping of the oscillating cantilever in dynamic atomic force microscopy (AFM) 

includes valuable information about the local vibrational structure and elastic compliance 

of the samples. We present atomically-resolved maps of damping in nanotube peapods, 

showing their capability of identifying the presence and location of encapsulated Dy@C82 

metallofullerenes as well as their packing structure in the different diameters of carbon 

nanotubes. In our study, the physical origin of damping is elucidated in a microscopic 

model, and its relationship to the outer tube diameter is quantitatively interpreted by 

calculating the vibrational spectrum and energy dissipation in peapods with different 

diameters using ab initio total energy and molecular dynamics calculations [1]. 

In our experiment we probed sparsely deposited (Dy@C82)@SWNT peapods on insulating 

oxide layers of a Si substrate by dynamic AFM under constant oscillation amplitude conditions in 

ultrahigh vacuum (p≈10 -8 Pa) and at low temperature (T≈13 K). As seen in Fig. 1(a), the 

atomically site-specific damping signal is obviously detected over the peapod. Besides, 

Figure 1(b) shows that its maximum energy is closely related to the enclosing nanotube 

diameter d, determined on the basis of the simultaneously observed topographic images. 

(a) (b) 

Figure 1: (a) Simultaneously obtained dynamic AFM topography (left) and damping (right) 

images of an empty SWNT (1,3) and a (Dy@C82)@SWNT peapod (2,4) with the same outer 

tube diameter d≈1.62 nm. (b) Relationship between outer tube diameter d and the maximum 

damping energy ΔEmax. 

[1] M. Ashino, R. Wiesendanger, A. N. Khlobystov, S. Berber, and D. Tománek, 

submitted for publication. 

64

We-1220 

Theoretical study of the forces and atomic configurations of NC-AFM 

P. Pou 1 , and R. Perez 1 

experiments on low-dimension carbon materials. 

1 Dpto. de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain 

During the last years we have been witnessing the rise of low-dimension carbon-based 

materials. Fullerenes, nanotubes and graphene are nowadays key materials nowadays key 

materials for nanotechnology applications due to their promising electronic and 

mechanical properties. The outstanding capabilities of NCAFM to image, manipulate and 

determine the tip-surface forces at the atomic scale make it the technique of choice for 

the study of the basic properties and for the development of these materials [1-5]. 

In this work we present a DFT study of the interaction of a large set of AFM tips 

with different low-dimension carbon materials. We have considered several possible tip 

terminations: reactive clean Si tip apexes, non-reactive apexes, oxygen contaminated Si 

apexes and metallic tips. For each of these tips, we have characterized both the 

conservative and non-conservative part of the tip-sample interaction, determining the 

force versus distance curves during approach and retraction and calculating also the 

dissipated energy. Our results provide insight into the origin of the atomic contrast 

observed in recent experiments on both graphite and a SWNT [2-4]. Moreover, we have 

studied the atomic origin of the particular 3D Force mapping obtained in the experiments 

on peapods constituted by endo-fullerenes inserted in a SWNT [1] (see Fig. 1). 

a) b) 

Figure 1: (a) Ball-and-stick model of Si tip apex model over (Dy@C82)@SWNT. (b) Electronic 

charge density calculated with DFT in a plane parallel to the peapod over the top atoms of the 

SWNT. A slight modulation produced by the Dy@C82 is observed. 

[1] M. Ashino et al. Nature Nanotech. 3, 337 (2008). 

[2] B. J. Albers et al. Nature Nanotech. 4, 57 (2009). 

[3] S. Hembacher et al. PNAS. 100, 12539-12542 (2003); S. Hembacher et al. PRL 94, 056101 (2005). 

[4] M. Ashino et al. PRL 93, 136101 (2004); M. Ashino et al. Nanotechnology 16, S134-S137 (2005). 

[5] H. Hölscher et al. Phys. Rev. B 62, 6967-6970 (2000). 

65

Anchoring highly polar molecules onto an ionic crystal 

We-1430 

Jens Schütte 1 , Ralf Bechstein 1,2 , Michael, Rohlfing 1 , Michael Reichling 1 , and Angelika 

Kühnle 1 



Precise control of molecular structure formation on surfaces is most important for 

creating functional molecular devices for future molecular (opto)electronics applications. 

So far, however, controlled structure formation on dielectric surfaces has often been 

hindered by weak molecule-substrate interactions, frequently leading to clustering at step 

edges [1]. Here, we explore the possibility of increasing the molecule-substrate 

interaction by deposition of a molecule having a high dipole moment, cytosine, onto the 

surface of an ionic crystal, CaF2(111). Our results reveal molecular trimer structures that 

are stable at room temperature. Density-functional theory calculations provide insights 

into molecular diffusivity and structure formation. Our findings indicate that employing 

well-adapted molecules with high dipole moment constitutes a promising strategy for 

controlling structure formation on insulating surfaces. 

Figure 1: (a) Overview image showing cytosine structures on CaF2(111) at room temperature. 

The most dominant structure is a trimer as marked by a box. (b) Zoom into the marked region of 

(a), revealing a molecular structure that can be explained by three cytosine molecules forming a 

hydrogen-bonded ring. The model in the lower part illustrates a plausible adsorption position with 

respect to the underlying substrate. 

[1] T. Kunstmann et al., Phys. Rev. B 71, 121403 (2005); S. Maier et al., Small 4, 1115 (2008). 

66

Steering the formation of molecular nanowires and compact 

nanocrystallites on NaCl(001) 

We-1450 

Sweetlana Fremy 1 , Alexander Schwarz 1 , Knud Laemmle 1 , Roland Wiesendanger 1 , and 

Marc Prosenc 2 

1 Institute of Applied Physics, University of Hamburg, Jungiusstr. 11, 20355 Hamburg, Germany 

2 Institute of Anorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King Platz 6, 20146 

Hamburg, Germany 

Recently, molecular-based magnetism raised a considerable interest in the scientific 

community. It is envisaged that the flexibility of organic synthesis might allow in the 

future to combine magnetism with other physical properties like transparency or optical 

switchability to create multifunctional devices. Investigations of such molecules using 

local probes have been mostly performed on metallic surfaces. However, due to strong 

hybridization the electronic state, and hence the magnetic properties as well, of adsorbed 

molecules is usually strongly modified. 

Fig. 1: (a) Co-Salen molecule. (b) Nanowire networks and compact nanocrystallites on NaCl(001). 

(c) Molecular resolution on a compact nanocrystallite reflecting the curved shape of Co-Salen. 

Therefore, we deposited Co-Salen (see Fig. 1a), a paramagnetic metal-organic Schiff- 

Base complex, on NaCl(001), a bulk insulator, by in-situ thermal evaporation. Since the 

molecular states are located in the band gap of this insulating substrate, hybridization 

effects are absent. Co-Salen on NaCl(001) forms either compact nanocrystallites or 

networks of nanowires or a mixture of both (see Fig. 1b). We found that the assembly of 

these different molecular nanostructures can be controlled by adjusting appropriate 

growth parameters. Moreover, the arrangement of the molecules in both morphologies 

could be resolved by performing molecular resolution imaging (see Fig. 1c). It turned out 

that the adsorption geometry at step edges, where nucleation takes place, is crucial to 

understand initial formation and growth of the two different morphologies. 

67

2-Dimensional growth of phenylenediboronic acid assisted by 

H-bonding 

We-1510 

R. Pawlak, L. Nony, F. Bocquet, M. Sassi, V. Oison, J.-M. Debierre, Ch. Loppacher, 

and L. Porte 

IM2NP, Aix-Marseille Université, Avenue Escadrille Normandie-Niemen, F-13397 Marseille Cedex 20, 

and CNRS, IM2NP (UMR 6242), F-13397 Marseille-Toulon, France 

Christian.Loppacher@im2np.fr 

Organic molecules are often synthesized in order to support the formation of selfassembled 

nanostructures. In such a way, directed non-covalent [1] as well as covalent 

interactions [2] have already been used to tune the size as well as the shape of molecular 

assemblies. 1,4 Phenylenediboronic acids (C6H8B2O4, BDBA) are molecules which are 

designed to engage in multiple interactions with neighbors via their –B(OH)2 groups, 

either by hydrogen bonding or by covalent bonding (obtained by molecular dehydration). 

In our work, we investigate the molecular growth of BDBA on the surface of singlecrystal 

potassium chloride (KCl) as well as on highly oriented pyrolytic graphite (HOPG) 

by means of noncontact atomic force microscopy (ncAFM). Other than on the surface of 

Ag(111) BDBA does not form the honey-comb like covalent network [3], but rather 

forms chains of hydrogen-bonded dimers, and the chains then associate by lateral 

hydrogen bonding to create sheets [4]. The ncAFM results displayed in the figure below 

show that extended and well organized monolayers of BDBA are formed on KCl. The 

observed structure fits very well to the one observed in crystals where the benzene ring is 

tilted by ~ 40° with respect to the mean plane of the sheet [4]. Interestingly, this structure 

seems to be very stable since it is also observed on the surface of HOPG. Experimental 

results are discussed in respect with structural models as well as calculations of the 

reaction path for the formation of covalent networks. 

Figure 1: 0.5 ML of BDBA adsorbed on KCl imaged by ncAFM. Large monolayer islands are 

formed which show the formation of sheets similar to the ones observed in single crystals. 

[1] T. Yokoyama et al., Nature 413, 619 (2001). 

[2] L. Grill et al., Nature Nanotechnology 2, 687 (2007) 

[3] N. Zwaneveld et al., JACS 190, 6678 (2008) 

[4] P. Rodriguez-Cuematzi et al., Acta Cryst. E60, o1315 (2004) 

68

Molecular scale dissipation in oligothiophene monolayers 

measured by dynamic force microscopy 

We-1530 

Carlos J. Gómez 1 , Nicolas F. Martínez 1 , Wojciech Kamiński 2,4 , Cristiano Albonetti 3 , 

Fabio Biscarini 3 , Ruben Perez 4 and Ricardo Garcia 1 

1 Instituto de Microelectronica de Madrid, CSIC, Isaac Newton 8 28760 Tres Cantos, Madrid, Spain 

2 Institute of Experimental Physics, University of Wrocław, p. Maksa Borna 9, 50-204 Wrocław, Poland 

3 CNR- (ISMN) Via P. Gobetti 101, I-40129 Bologna, Italy 

4 Dep. de Física Teórica de la Materia Condensada,Universidad Autónoma 28049 Madrid, Spain 

Amplitude modulation atomic force microscopy has enabled high resolution imaging of 

soft materials 1 and Phase-imaging has been applied to identify nanoscale dissipation 

processes 2 . We perform a combined experimental and theoretical approach to establish 

the atomistic origin of dissipation occurring while imaging a molecular surface with an 

amplitude modulation force microscope 3 . The configuration space sampled by the tip 

depends on whether it approaches or withdraws from the surface. The asymmetry arises 

because of the presence of energy barriers among different deformations of the molecular 

geometry. This is the source of the material contrast provided by the images. 

[1] R. Garcia, R. Magerle, R. Perez, Nat. Mater. 7, 405 (2007). 

[2] R. Garcia, C. J. Gomez, N. F. Martinez, S. Patil, C. Dietz, R. Magerle, Phy. Rev. Lett. 97, 016103 

(2006). 

[3] Phy. Rev. Lett. (2009) Accepted. 

69

Oral 

Presentations 

Thursday, 13 August 

70

Dependence of the atomic scale image of a Si adatom on the tip apex 

termination: a DFT study 

Anna Campbellova 1 , Pablo Pou 2 , Ruben Pérez 2 , Petr Klapetek 1 and Pavel Jelínek 3 

1 Czech Metrology Institute, Brno, Czech Republic 

2 Department of Physics, Yale University, New Haven, Spain. 

3 Department of Thin Films, Institute of Physics of the ASCR, Prague, Czech Republic 

Th-0900 

High-resolution measurements of tip-sample forces became possible with dynamic force 

spectroscopy (DFS) [1]. Furthermore this technique was adopted to measure threedimensional 

force ?elds with atomic resolution [2,3]. In principle, these measurements 

can provide, by separating the short-range contribution from the total tip-sample 

interaction, detailed information about e.g. the surface energy landscape, adhesion forces 

and inter-atomic forces. Sub-atomic resolution of Si adatoms on Si(111)-(7x7) has also 

been reported and its interpretation is still source of debate. 

Here we have performed DFT simulations of a 3D scan over a silicon cluster –that 

reproduces the local coordination of a surface adatom--, using different Sibased tips [5]. 

Our aim is to reveal the effect of apex atomic termination on the resulting atomic scale 

imaging of individual Si adatom. We have found a strong variation of the internal atomic 

contrast with the symmetry and chemical composition of the tip apex. In particular, the 

theoretical atomic image provided by a dimer-like Si tip with an oxygen atom positioned 

on apex mimics very well the characteristic subatomic features observed experimentally 

[4]. 

Figure 1: Theoretical DFT images of Si adatom provided by three different apex tip structures. 

[1] M. A. Lantz et al, Science 291, 2580 (2001). 

[2] H. Hölscher, S. M. Langkat, A. Schwarz, and R. Wiesendanger, Appl. Phys. Lett. 81, 4428 (2002). 

[3] Y. Sugimoto, T. Namikawa, K. Miki, M. Abe, and S. Morita Phys. Rev. B 77, 195424 (2008). 

[4] F. J. Giessibl, S. Hembacher, H. Bielefeldt, and J. Mannhart, Science 289, 422 (2000) 

[5] P.Pou et al Nanotechnology accepted (2009) 

71

AFM probe tips with a small front atom 

Th-0920 

T. Hofmann, 1 J. Welker, 1 M. Ternes, 2 C. P. Lutz, 2 A. J. Heinrich, 2 Franz J. Giessibl 1 

1 University of Regensburg, Institute of Experimental and Applied Physics, D-93040 Regensburg, Germany 

2 IBM Research Division, Almaden Research Center, 650 Harry Rd, San Jose, CA 95120, USA 

A direct comparison of scanning tunneling microscopy and AFM data showed that when 

probing a tungsten tip with a graphite surface (a “light-atom probe”), subatomic orbital 

structures with a spatial resolution of less than one Angstrom can be obtained in the force 

map, while a map of the tunneling current only shows the known atomic resolution. 1 

Optimized subatomic contrast is obtained when recording the higher harmonics of the 

cantilever motion. 1 The idea of the light atom probe was carried further by using an adsorbed 

CO molecule to probe the tip atom. It requires quite a large force to move a CO molecule 

laterally 2 and this molecule is an excellent probe for the orbital structure of the front atom of 

the metal tip. In contrast to previous examples of “subatomic” resolution, where a flat sample 

with a periodic array of sample atoms created multiple tip images, using a single adsorbed CO 

molecule as a “tip” allows to isolate the force contribution of a single atom-pair contact. 

Ideally, one wishes to create a probe with a perfectly perpendicularly oriented CO molecule at 

the very end of the tip. First results will be discussed where a CO molecule has been picked 

up by a metal tip and used to image adsorbed atoms. 

In order to allow simultaneous STM and AFM, high electrical conductivity is another 

desirable property of a light atom probe. Because of its small atomic radius, high mechanical 

strength and fair electric conductivity Beryllium is a promising choice as a probe material. 

However, due to its high reactivity, preparation is a challenge. Results using Be tips prepared 

by high-voltage field emission for atomic imaging of Si(111)-(7×7) will be presented. 

1. S. Hembacher, F. J. Giessibl, J. Mannhart, Science 305, 380 (2004). 

2. M. Ternes, C. P. Lutz, C.F. Hirjibehedin, F. J. Giessibl, A. J. Heinrich, Science 319, 1066 

(2008). 

72

Th-0940 

Intramolecular features of organic molecules characterized by force 

field spectroscopy: The case of PTCDA on Cu and Ag 

Gernot Langewisch 1 , Daniel-Alexander Braun 1 , Domenique Weiner 2 , 

Bartosz Such 3 , Harald Fuchs 1 , and Andre Schirmeisen 1 

1CeNTech (Center for Nanotechnology) and Institute of Physics, University of Muenster, Germany 

2 SPECS Zurich GmbH, Switzerland 

3 Marian Smoluchowski Institute of Physics, Jagiellonian University Krakow, Poland 

Thin films of π-conjugated organic molecules, like the organic semiconductor PTCDA, 

are of high relevance for nanoelectronic applications. We use non-contact atomic force 

microscopy in ultrahigh vacuum at room temperature to investigate the forces between 

the tip and PTCDA molecules deposited on Cu(111) and Ag(111) surfaces by molecular 

beam epitaxy. 

Submolecular features of the PTCDA layers on both substrates are resolved in the 

topography scans. In particular we find that the second layer molecules show an 

intramolecular structure with a height corrugation of up to 40pm, while molecules in the 

first layer above the substrate are depicted as featureless ovals [1]. To study this effect in 

detail, 2-dimensional cuts of the spatial tip-sample force landscape above individual 

molecules were obtained by force field spectroscopy. In the double layer these cuts, each 

consisting of 40 force spectroscopy curves, reveal an enhanced tip-sample force 

interaction at the molecular end groups compared to the centre of the molecule [2]. 

However, for the monolayer molecules this effect is not present. This is interpreted with 

respect to different mechanical relaxation processes of the molecular functional end 

groups as well as variations of the internal electron density distributions of the molecules. 

Figure 1: Left: Topography scans of a double layer of PTCDA molecules on Cu(111) deposited 

by molecular beam epitaxy, showing intramolecular contrast. Right: Force field spectroscopy 

image along line in left image, visualizing the intramolecular variations of the tip-sample force. 

[1] B. Such, A. Schirmeisen, D. Weiner, and H. Fuchs, Appl. Phys. Lett. 98, 093104 (2006). 

[2] D.-A. Braun, D. Weiner, B. Such, H. Fuchs and A. Schirmeisen, Nanotechnology (2009) submitted. 

73

Th-1000 

Analysis of bimodal and higher mode small-amplitude near-contact 

AFM and energy dissipation 

S. Kawai, A. Baratoff, Th. Glatzel, S. Koch, B. Such, and E. Meyer 

Department of Physics, University of Basel, Klingelbergstr. 82, 4056 Basel Switzerland 

Recently enhanced atomic-scale contrast was achieved on KBr(001) in UHV using 

resonant self-excitation of the lowest two cantilever flexural modes with constant tip 

oscillation amplitudes A1 >> A2 by monitoring the interaction induced frequency shift Δf2 

while controlling the closest approach distance z via Δf1 [1]. Optimum sensitivity and 

contrast in non-contact AFM using the 2 nd mode alone can in principle be achieved for z 

below the interatomic separation and A2 close to the range of the tip-sample interaction [2 

3]. Stable operation under such conditions can, however, be jeopardized by atomic jumps 

even if macroscopic jump-to-contact is prevented by using a sufficiently stiff deflection 

sensor. Simultaneous excitation of the fundamental mode with a large A1 alleviates this 

problem for reasons to be discussed. 

Under the stated conditions, Δf2 is to a good approximation proportional to the time 

average of the interaction force gradient over one cycle of the fundamental oscillation, as 

demonstrated and verified by simulations and measurements [1]. An application of the 

same argument to atomic-scale Kelvin Force Microscopy using voltage modulation at f2 

shows that the resulting deflection signal at f2 is proportional to the time average of the 

electrostatic force [4]. 

Measurements to be reported separately using the 2 nd mode alone with amplitudes as 

small as 0.5 nm show smooth force vs. distance curves extracted from Δf2, as well as a 

small time-averaged deflection proportional to the time-average of the force. 

In all three cases, the site-dependent distance dependence of the time-averaged force 

gradient, electrostatic or total force can be extracted from the measured frequency shift, 

deflection signal at f = f2 or f = 0 using slightly modified versions of inversion algorithms 

proposed for single-mode non-contact AFM [5, 6] 

The magnitude, distance and amplitude dependences of the interaction-induced energy 

dissipation per oscillation cycle simultaneously measured using the 2 nd mode suggest that 

the dominant cause of dissipation is a force hysteresis loop narrower than twice A, but 

significantly smeared by thermal activation. However, some velocity-dependent 

damping with a coefficient decaying with increasing distance must also be present. 

Possible mechanisms and a hitherto ignored difficulty in extracting meaningful 

"dissipative forces" in the presence of both mechanisms will be discussed. 

[1] S. Kawai et al., submitted. 

[2] F. J. Giessibl et al., Appl. Surf. Sci.140, 352 (1999). 

[3] S. Kawai et al., Appl. Phys. Lett. 89, 023113 (2006). 

[4] S. Kawai et al., unpublished 

[5] O. Pfeiffer et al., Phys. Rev. B 65, 161403R (2002) 

[6].J. E. Sader and S. P. Jarvis, Appl. Phys. Lett. 84, 1801 (2004) 

74

Th-1020 

Adhesion-induced energy dissipation and atom-tracked tip changes 

S. Kawai, Th. Glatzel, S. Koch, B. Such, A. Baratoff, and E. Meyer 


We have simultaneously measured the frequency shift Δf and the interaction-induced 

dissipated energy per cycle Ets above a maximum in a topographic image of KBr(001). 

The measurements were performed at room temperature in UHV using the 2nd flexural 

mode of a silicon cantilever (1039369 Hz) at 11 constant amplitudes A between 12.8 and 

0.51 nm. As shown in fig. 1, Ets rises smoothly above the noise level, then almost 

saturates as the closest approach distance extends below the attractive force minimum. 

Whereas the conservative force vs. distance curves extracted from Δf were smooth and 

coincided apart from noise, Ets decreased smoothly by only a factor of 2 and became less 

noisy as A was reduced from 12.8 to 0.51 nm. This behavior, and the magnitude of Ets 

suggest that the dominant cause of dissipation is a force hysteresis loop narrower than 

twice A, but significantly smeared by thermal activation. However, some velocitydependent 

damping with a coefficient decaying with increasing distance is also present. 

Using A = 0.285 nm, one thousand approach-retraction curves were recorded, separated 

by intervals for atom-tracking (Nanonis AT4). In most cases one of three distinct Ets vs. 

distance curves are obtained, whereas the conservative force curves are almost the same, 

as shown in fig. 1 (a-c). This is consistent with the higher sensitivity of Ets to the tip apex 

configuration. In a few cases we observed jumps between curves corresponding to two of 

those long-lived configurations, accompanied by significant deviations between approach 

and retraction. As shown in fig. 2, the tracked 3D motion of the sample relative to the tip 

at Δf = -150 Hz exhibits strong correlations between more frequent jumps (strongly 

reduced by averaging over each tracking interval). This suggests that tip changes occur 

over a range of time scales. Further implications of those results will be discussed. 

Figure 1 Figure 2 

75

Th-1120 

Combined Qplus-AFM and STM imaging of the Si(100) surface: 

Activating the c(4x2) to p(2x1) transition with subnanometre oscillation 

amplitudes 

A. Sweetman, S. Gangopadhyay, R. Danza, and P. Moriarty 

School of Physics and Astronomy, University of Nottingham, 

Nottingham NG7 2RD, UK 

We report the first combined Qplus AFM and STM images of the Si(100) surface. The 

study of the Si(100)-(2x1) and c(4x2) reconstructions using scanning probe methods 

(both STM and NC-AFM) has led to a variety of intriguing and controversial issues 

associated with identifying the ground state of the system [1]. Foremost among these 

have been the determination of whether the silicon dimers, which give rise to the (2x) 

periodicity at the Si(100) surface, are asymmetric or symmetric, and the extent to which 

the measurement technique might influence the energy balance. Previous experimental 

NC-AFM measurements (with ~ 10 nm amplitude) combined with theoretical 

calculations [2] showed that the AFM probe could strongly influence the Si(100) surface, 

stabilising a p(2x1) phase at low temperatures. Our Qplus measurements, taken with 

probe oscillation amplitudes ranging from 250 pm to 10 nm, not only confirm that the 

strong influence of the tip is retained at subnanometre oscillation amplitudes, but, as 

shown in Fig. 1, suggest that tip symmetry plays a central role in stabilisation of a 

particular surface phase. In addition, there are clear and striking differences between 

STM and Qplus AFM images of the Si(100)-(2x1) phase arising from the residual dimer 

buckling associated with probe-induced stabilisation of the p(2x1) structure. 

[1] Lev Kantorovich and Chris Hobbs, Phys. Rev. B 73 245420 (2006) and references therein 

[2] Yan Jun Li et al., Phys. Rev. Lett. 96 106104 (2006) 

Fig. 1 Qplus AFM images of the Si(100) surface. (a) Regions of both (2x1) and c(4x2) 

symmetry are visible. (df=-10.9 Hz, A vib=350 pm (700 pm pk-pk), V gap=+0.3V). (b) and (c) 

Images of the same surface region taken in parallel with identical scan parameters showing the 

influence of the scan direction on the surface phase. Image (b) was taken while the tip was 

moving from left to right. For Image (c) the tip was moving from right to left. 

76

Measuring Atomic Charge States by nc-AFM 

Th-1140 

Leo Gross 1 , Fabian Mohn 1 , Peter Liljeroth 1,2 , Jascha Repp 1,3 , Franz J. Giessibl 3 , and 

Gerhard Meyer 1 

1 

IBM Research, Zurich Research Laboratory, 8803 Rüschlikon, Switzerland 

2 

Debye Institute for Nanomaterials Science, Utrecht University, 3508 TA Utrecht, The Netherlands 

3 

Institute of Experimental and Applied Physics, University of Regensburg, 

93040 Regensburg, Germany 

We investigated the charge state switching of individual gold and silver adatoms on 

ultrathin NaCl films on Cu(111) using a qPlus tuning fork AFM operated at 5 Kelvin 

with oscillation amplitudes in the sub-Ångstrom regime. Charging of a gold adatom by 

one electron charge increases the force on the AFM tip by a few piconewtons. Moreover, 

the local contact potential difference is shifted depending on the sign of the charge and 

allows the discrimination of positively charged, neutral, and negatively charged atoms. 

Furthermore, we modified AFM tips by means of vertical manipulation techniques, i.e. 

deliberately picking up known adsorbates, to study the effect of the atomic tip 

termination on AFM contrast and sensitivity. 

77 

Figure 1: (a) Constant-current STM 

measurement (V = –50mV, I = 2pA) of a 

neutral (Au 0 , left) and a negatively charged 

gold adatom (Au − , right) adsorbed on 

NaCl(2ML)/Cu(111). The line scan is 

through the center of both adatoms shown 

in the inset (image size of insets: 

55Å × 17Å). (b) Current and (c) frequency 

shift recorded simultaneously in a constantheight 

measurement of the same area 

(Δz = 5.0Å, V = –5mV, A = 0.3Å).

Th-1200 

Mechanism of Dissipative Interaction by Tunneling Single-Electrons 

Yoichi Miyahara 1 , L. Cockins 1 , S. D. Bennett 1 , A. A. Clerk 1 , S. A. Studenikin 2 , 

P. Poole 2 , A. Sachrajda 2 and P. Grutter 1 

1 Department of Physics, McGill University, Montreal, Canada 

2 Institute for Microstructural Science, National Research Council of Canada, Ottawa, Canada 

The frequency modulation mode atomic force microscopy (FM-AFM) can be used as a 

sensitive electrometer which can detect the motion of a single electron. An oscillating 

AFM tip with an applied dc-bias voltage (Vbias) can allow a single electron to tunnel back 

and forth between a quantum dot (QD) and a back-electrode by oscillating the chemical 

potential of the QD around that of the back-electrode, owing to Coulomb blockade effect. 

The resulting electron motion in turn modulates the electrostatic force acting on the tip 

and causes the dissipation as well as the resonance frequency shift (Δf) of the cantilever. 

Both dissipation and Δf images taken in constant-height mode show characteristic 

concentric rings around the QD, each of which reflects the above-mentioned single- 

electron tunneling. The corresponding features also appear as peaks (dips) in the 

dissipation (Δf) versus Vbias spectra taken above the QD. These spectra can be interepreted 

as addition energy spectra which enable us to investigate the electronic structure of a 

single QD. 

In this contribution, we present the mechanism of the dissipative electrostatic 

interaction due to the tunneling single-electrons in detail. In essence, this dissipative 

interaction arises from the delayed response of a single tunneling electron to the 

oscillating chemical potential induced by the oscillating tip. The delay is due to the finite 

tunneling rate which is determined by the tunnel barrier. 

We developed a theoretical model for this dissipation process and obtained a very 

good agreement between the theoretical dissipation versus Vbias curve and the 

experimental one (Fig. 1). We also discuss the effect of the tip oscillation amplitude and 

temperature and the relation between Δf and dissipation signal. 

78 

Figure 1: Theoretical (solid) and 

experimental (dashed) dissipation versus 

bias voltage curves. (T = 30 K, A=0.5 nm, 

Tip-QD distance = 15 nm)

Th-1220 

Controlling electron transfer processes on insulating surfaces with the 

NC-AFM 

Thomas Trevethan 1,2 and Alexander Shluger 2 

1 Department of Physics and Astronomy, University College London, London, UK 

2 WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan. 

We present theoretical modeling that predicts how a single electron transfer process can 

be induced between two defects on an insulating surface using the non-contact Atomic 

Force Microscope. On an insulating substrate one can realize the possibility of using the 

localized perturbation produced by an AFM tip to modify electronic structure locally on 

the surface, which could result in the control of electronic processes and transitions. The 

field produced by the tip at close approach may modify both the relative energies of 

distinct electronic states as well as the potential energy barrier separating them. 

A model but realistic system is employed which consists of a neutral oxygen vacancy and 

a noble metal (Pt or Pd) adatom on the MgO (001) surface. We show that the ionization 

potential of the vacancy and the electron affinity of the metal adatom can be significantly 

modified by the electric field produced by an ionic tip apex at close approach to the 

surface. The relative energies of the two states are also a function of the separation of the 

two defects. Therefore the transfer of an electron from the vacancy to the metal adatom 

can be induced either by the field effect of the tip or by manipulating the position of the 

metal adatom on the surface. We also show how the transition of an electron can be 

observed in the change of image contrast. The realization of these procedures 

experimentally would mean that a single electron transfer process could be directly 

observed and controlled, and would herald a new regime of control on the atomic scale. 

Figure 1: (a) Schematic of the system, showing an Mg terminated MgO tip directly above a 

metal adatom on the surface, adjacent to an oxygen vacancy. (b) Illustration of adiabatic total 

energy curves for the two states at two defect separations (A > B), where Q is a structural degree 

of freedom. (c) Illustration of potential energy wells for the two states, depicting how barrier 

width increases at larger separation. 

79

Th-1240 

NC-AFM imaging with atomic resolution in a temperature range 

Andreas Bettac and Albrecht Feltz 

between 5 K and 1083 K 

Omicron NanoTechnology GmbH, Taunusstein, Germany 

We present the latest results of atomically resolved NC-AFM (QPlus) measurements on a 

Si(111) 7x7 surface at high sample temperatures. Starting at room temperature, the 

temperature was increased stepwise to 1083 K by direct current heating. Even at these 

high temperatures it is possible to achieve atomic resolution of the 7x7 reconstruction in 

NC-AFM mode (Fig 1a) . 

Since the phase transition between the 1x1 and the 7x7 reconstruction starts to occur at 

this temperatures, we focused our experiments on the observation of the phase transition. 

In NC-AFM and dynamic STM mode we observed fluctuating formations of step edges 

and kinks. Typically, these kinks have a width of half a unit cell - most likely due to 

breaking the dimer bonds. Both effects are indicators for the phase transition. At the same 

high temperature and without changing the sensor we were able to image this 

characteristic step movement in STM mode with atomic resolution of the 7x7 

reconstruction. The size of the 1x1 areas at the lower side of a step edge permanently 

changes - affecting the 7x7 area. 

With the developed instrument we could resolve the rest atoms of the Si(111) 7x7 

reconstruction at a sample temperature of 50 K and observed a different brightness for the 

rest atoms of the faulted and unfaulted half (Fig. 1b). 

Furthermore, atomic resolution in NC-AFM mode on metallic Au(111) and Ag(111) 

surfaces at 5 K will be presented [1]. 

a) b) c) 

T= 1053 K 

T= 50 K T= 5 K 

Figure 1: NC-AFM results: a) atomically resolved 

Si(111) 7x7 at a sample temperature 

of 1053 K; b) Si(111) 7x7 at 50K, the atomically resolved image of the Si(111) 7x7 

surface clearly shows the restatoms and their different brightness for the faulted and 

unfaulted half; and c) atomically resolved Au(111) surface at 5K. 

[1] 

A. Bettac, J. Koeble, K. Winkler, B. Uder, M. Maier, and A. Feltz, Nanotechnology 20, 264009 (2009). 

80

Oral 

Presentations 

Friday, 14 August 

81

Th-1240 Fr-0900 

Atomic scale elasticity mapping of Ge(001) surface by multifrequency 

FM-AFM 

Yoshitaka Naitoh, Zongmin Ma, Yanjun Li, Masami Kageshima and Yasuhiro Sugawara 

Department of Applied Physics, Osaka University, Suita 565-0871, JAPAN 

Surface elasticity is quite important to study atomic scale properties of the surface 

such as bounding strength of surface atoms and surface phonons. The conventional FM- 

AFM provides topographic information of various surfaces at atomic scale. However, it is 

hardly accessible to the elasticity and the adhesion on surfaces. In this study, we propose 

a new technique, multifrequency FM-AFM, on Ge(001) surface using a commercial 

cantilever in order to investigate the surface elasticity at atomic scale with the 

topographic image. 

The cantilever of the multifrequency FM-AFM was simultaneously excited at the 

by two sets of automatic gain 

1st and the 2nd flexural resonant frequencies (f1st, f2nd) 

controller and phase locked loop electronics. Their oscillating amplitudes are set constant 

at A1st, A2nd. The cantilever oscillating signal, detected by an optical interferometer 

system, is divided into the 1st and the 2nd components through band pass filters. The 

surface topography is obtained from feedback signal maintaining the frequency shift of 

the 1st component (Δf1st) constant. From the theoretical consideration, we found that the 

surface elasticity is obtained as a mapping of the frequency shift of the 2nd component 

(Δf2nd). 

The cleaned Ge(001) surface showing buckled dimer structure was adopted as a 

sample with the elastic distribution at atomic scale. Figures 1(a) and (b) show the 

simultaneously obtained topography and the Δf2nd mapping of the surface. The dimer 

structure of the surface was clearly resolved in both images. We found Δf2nd of the fig. 

1(b) was high at the dimer atom position in comparison with the topography. This result 

suggests multifrequency FM-AFM is a nicer tool for exploring the surface elasticity at 

atomic scale. 

Figure 1: (a) Topographic image of Ge(001) surface with Δf1st=-70Hz, f1st=160kHz and 

A1st=4nm. Scan area is 7x7 nm 2 . (b) Simultaneously obtained Δf2nd mapping of the surface area 

with Δf2nd=-21Hz, f2nd=1.0MHz and A2nd=0.3nm. 

82

Small amplitude atomic resolution NC-AFM imaging and force 

spectroscopy experiments using a stiff piezoelectric force sensor 

Stefan Torbrügge 1 , Jörg Rychen 2 , Oliver Schaff 1 

1 SPECS GmbH, Voltastrasse 5, 13355 Berlin, Germany 

2 SPECS Zurich GmbH, Technoparkstrasse 1, 8005 Zurich, Switzerland 

Fr-0920 

We present the design of the recently introduced KolibriSensor TM and its application to 

frequency modulation atomic force microscopy. The KolibriSensor TM , schematically 

shown in Fig. 1(a), is a new type of piezoelectric force sensor based on a quartz length 

extension resonator (LER) [1]. Key features of the KolibriSensor TM are a high spring 

constant (k~540,000 N/m), avoiding snap into contact when operated at small amplitudes, 

and a large Q-factor exceeding 10,000 at room temperature. Its high resonance frequency 

(fres~1 MHz) enables fast scanning and an excellent signal-to-noise ratio necessary for 

stable operation at sub-nanometer oscillation amplitudes. In-situ sputtering enables 

repeated sharpening of the separately contacted tungsten tip. Switching between AFM, 

STM, or combined feedback modes is possible on the fly during measurement. 

We demonstrate atomic resolution measurements on Si(111)-(7x7) and insulating 

KBr(001), see Fig. 1(b), with oscillation amplitudes down to 30 pm at room temperature 

and scanning speeds of several lines/s. Furthermore the performance of the sensor in 

force spectroscopy experiments is evaluated by acquisition of two-dimensional force 

maps measured on KBr(001) (see Fig. 1 (c)). 

Figure 1: (a) Schematic drawing of the KolibriSensor TM . (b) Topographic atomic resolution NC- 

AFM image of the KBr(001) surface recorded at room temperature. (c) Vertical tip-sample force 

map F(x,z) derived from 20 Δf(z) curves taken along the line in the insert image in (c). 

[1] T. An, et al. Appl. Phys. Lett., 88, 149903 (2006); T. An, et al., Rev. Sci. Instrum., 79, 033703 (2008) 

83

Fr-0940 

Determination of the Optimum Spring Constant and Oscillation 

Amplitude for Atomic/Molecular-Resolution FM-AFM 

Yoshihiro Hosokawa 1 , Kei Kobayashi 2 , Hirofumi Yamada 1 and Kazumi Matsushige 1 

1 Department of Electronic Science and Engineering, Kyoto University, Kyoto, Japan 

2 Innovative Collaboration Center, Kyoto University, Kyoto, Japan. 

Several studies have shown that the lateral resolution of FM-AFM on Si(111)-7x7 surface 

can be improved by oscillating a force sensor with a very high spring constant (> 1,000 

N/m) at a very small amplitude (< 1 nm) [1,2]. However, the resolution of FM-AFM on 

an organic thin film was not improved by the use of a cantilever with a spring constant of 

about 700 N/m [3]. Here we propose a general procedure to determine the optimum 

imaging parameters (spring constant and oscillation amplitude) for obtaining atomic or 

molecular resolution by FM-AFM. 

We first determine the minimum distance between the tip and the sample, which is 

limited by the instability caused by jump-into-contact the sample or by the dissipative tipsample 

interaction forces. Then we defined effective signal intensity for atom/molecularresolution 

FM-AFM as the difference between the frequency shift on top of the 

atom/molecule and on the gap between the atoms/molecules at the minimum distance. 

Figure 1 shows a plot of the calculated signal-to-noise ratio on lead-phthalocyanine thin 

films on MoS2. The optimum spring constant and oscillation amplitude were 10 N/m and 

25 nm, respectively. Figure 2(a) is a preliminary experimental result using 7.4 N/m 

cantilever. Line profiles obtained from Fig. 2(a) (red, bold) and from the image (black, 

thin) using 40 N/m cantilever [3] are shown in Fig. 2(b). From Fig.2(b), the corrugation 

was larger and consequently signal-to-noise ratio was improved when we used a 

cantilever with a smaller spring constant and a larger oscillation amplitude. 

Figure 1: Signal-to-noise ratio for 

molecular-resolution FM-AFM on PbPc with 

various spring constant and oscillation 

amplitude. The optimum spring constant and 

oscillation amplitude is 10 N/m and 25 nm. 

[1] F. J. Giessibl et al., Appl. Surf. Sci., 140 (199) 352. 

[2] S. Kawai et al., Appl. Phys. Let., 86 (2005) 193107. 

[3] Y. Hosokawa et al., Jpn. J. Appl. Phys., 47(2008) 6125. 

84 

Figure 2: (a) Topographic 

image of PbPc 

obtained with using small spring constant 

cantilever (7.4 N/m) at large amplitude (15 

nm). (b) Line profiles obtained from (a) 

(red, bold) and from the image obtained 

using 40 N/m cantilever

Fr-1000 

Visualization of Anisotropic Conductance in Polydiacetylene Crystal 

by Two-probe FM-AFM/KFM 

Eika Tsunemi 1 , Kei Kobayashi 2 , Kazumi Matsushige 1 , and Hirofumi Yamada 1 

1 Department of Electronic Science & Engineering, Kyoto University, Katsura Nishikyo, Kyoto, Japan 

2 Innovative Collaboration Center, Kyoto University, Katsura Nishikyo, Kyoto, Japan 

Atomic force microscopy probe tips serve as a wide variety of roles such as 

nanometer-scale electrical probes or atom manipulation tools in addition to imaging tools. 

However, their simultaneous, multiple use is often limited because only a single probe is 

available in AFM. Implementation of two or more probe tips can tremendously expand 

the capability of AFM. We recently developed a high-resolution two-probe AFM system 

using the optical beam deflection method [1]. It allows us to make a multi-probe 

electrical measurement or to conduct stimulus-response experiments for various materials. 

In this presentation, anisotropic conduction in a polydiacetylene (PDA) single 

crystal was studied by the two-probe FM-AFM/KFM. A PDA single crystal shows an 

anisotropic conductance due to the quasi-one-dimentional electronic band structure along 

the diacetylene main chain. In this experiment, we used a poly-PTS (polydiacetylene 

para-toluene sulfonate) single crystal (inset of the right of Fig. 1). The left of Fig. 1 

shows an experimental setup. While a bias voltage was locally applied to the surface with 

Probe-1, the surface potential was mapped with Probe-2 as a FM-KFM probe to visualize 

the injected carrier distribution. An obtained KFM image (the right of Fig. 1) shows that 

the higher potential region extends linearly along the PDA main chain from the Probe-1 

contact point, which means that the carriers injected from Probe-1 travel mainly through 

the diacetylene chain. In addition, the effect of a defect on the carrier transport was 

investigated. We positioned Probe-1 at a point on a line parallel to the main chain through 

a line defect which we had found. The right image of Fig. 2 shows that the potential 

sharply drops near the edge of the defect, which indicates a resistance increase at this 

point. 

Figure 1: AFM (Left) and KFM (Right) images 

of a poly-PTS single crystal obtained by twoprobe 

FM-AFM/KFM. Schematic of two-probe 

measurement is also shown (Left). 

[1] E. Tsunemi et al, Jpn. J. Appl. Phys. 46, 5636 (2007). 

85 

Figure 2: AFM (Left) and KFM (Right) 

images of a poly-PTS single crystal surface 

with a line defect.

Scattering Scanning Near-Field Optical Microscopy 

performed by NC-AFM 

Fr-1020 

Ulrich Zerweck 1 , S.C. Schneider 1 , M.T. Wenzel 1 , H.-G. von Ribbeck 1 , S. Grafström 1 , 

R. Jacob 2 , S. Winnerl 2 , M. Helm 2 , and L.M. Eng 1 

1 Institute of Applied Photophysics, Technische Universität Dresden, Dresden, Germany, 

2 Forschungszentrum Dresden Rossendorf, Dresden, Germany 

Many samples of interest show resonances in the IR to THz range, which are based 

e.g. on phonons or on chemical bonding. At these wavelengths, the classical optical 

resolution is strongly limited by the diffraction limit. In scattering scanning near-field 

optical microscopy (s-SNOM), an AFM tip operated in the non-contact mode is used both 

for the electric field concentration and the field enhancement at the tip apex to increase 

the optical resolution. The method is independent of the wavelength, and hence allows 

for high resolution measurements even at very large wavelengths (IR and THz 

frequencies). 

We combine s-SNOM with the free-electron laser (FEL) at the Forschungszentrum 

Dresden-Rossendorf 2 used as a precisely tunable and monochromatic high-power light 

source covering a wavelength range from 4 to 200 µm. With this unique setup, we are 

able to perform optical imaging of a sample as well as spectroscopy by tuning the 

wavelength of the FEL [1] (see Fig. 1). 

We study different types of phonon-resonant samples such as ferroelectric LiNbO3 

and BaTiO3, semiconductors with different doping concentrations, and Si-SiO2 

nanostructures. 

Figure 1: a) Sketch of the s-SNOM setup inspecting uniaxial ferroelectric BaTiO3 with 

orientation of its optical axis perpendicular or parallel to the sample surface on different domains; 

b) near-field imaging of BaTiO3 with contrast reversal at different optical wavelengths, and c) 

distance-dependent near-field spectroscopy on BaTiO3. 

[1] S.C. Schneider, PhD thesis, TU Dresden, Germany (2007) 

86

Atomic resolution dynamic lateral force microscopy in liquid 

Shuhei Nishida, Dai Kobayashi, Noriyuki Okabe, and Hideki Kawakatsu 

Fr-1120 

Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan 

snishida@iis.u-tokyo.ac.jp 

A key step to achieve atomic resolution imaging in dynamic lateral force 

microscopy (DLFM) is to reduce the lateral tip amplitude down to less than atomic lattice 

scale of the sample. Use of high-frequency cantilever vibration modes is effective for 

reducing the tip amplitude. In this contribution, we demonstrate atomic resolution DLFM 

imaging in liquid using a high-frequency torsional mode. 

We performed the DLFM imaging using an optically based method combining 

photothermal excitation and laser Doppler velocimetry for utilizing various cantilever 

vibration modes [1,2]. We excited and detected the first torsional mode with the 

resonance frequency of 1.15 MHz, and reduced the lateral tip amplitude down to 1.3 Å 

with keeping vibration stability. 

Figure 1(a) shows a DLFM image of a muscovite mica surface immersed in purified 

water. The small tip amplitude around a quarter of the mica’s lattice constant allowed us 

to achieve atomic resolution imaging. Cross sectional analysis of the image at the 

meandering features suggests that the force acting on the tip from a tetrahedral silicate 

group was overlapped with the force from the neighboring silicate group along the 

vibration direction (Fig. 1(b)). 

(a) (b) 

Figure 1: DLFM imaging of a muscovite mica surface immersed in purified water. (a) A 

topographic image, drive frequency: 1,158,225 Hz, scan size: 10 x 10 nm 2 . (b) A line profile 

along the solid line in (a). 

[1] S. Nishida, D. Kobayashi, T. Sakurada, T. Nakazawa, Y. Hoshi, and H. Kawakatsu, Rev. Sci. Instrum. 

79, 123703 (2008). 

[2] S. Nishida, D. Kobayashi, H. Kawakatsu, and Y. Nishimori, J. Vac. Sci. Technol. B 27, 964 (2009). 

87

Fr-1140 

Molecular-scale Investigations of Biomolecules in Liquids by FM-AFM 

Shinichiro Ido 1 , Noriaki Oyabu 1,2 , Kei Kobayashi 2,3 , Yoshiki Hirata 4 , Masaru Tsukada 5 , 

Kazumi Matsushige 1 , and Hirofumi Yamada 1,2 


2 Japan Science and Technology Agency /Adv. Meas. & Analysis, Japan 

3 Innovative Collaboration Center, Kyoto University, Kyoto, Japan 

4 National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan 

5 Advanced Institute for Materials Research,Tohoku University ,Sendai, Japan 

Recent, rapid progress in high-resolution frequency modulation atomic force 

microscopy (FM-AFM) in liquid environments has opened a new way to directly 

investigate "in vivo" biological processes with molecular resolution [1,2]. In this study, 

submolecular-resolution imaging of DNA molecules and proteins has been conducted 

toward the molecular scale analysis of DNA-protein interactions dominating site-specific 

binding of proteins to DNA. In addition, three-dimensional (3D) hydration structures on 

the biomolecules have been visualized for exploring the roles of water molecules in the 

biological functions. 

A low-thermal-drift FM-AFM developed based on a commercial AFM apparatus 

with a home-built low-noise electronics system. Figure 1(a) shows an FM-AFM image of 

a pUC18 plasmid DNA (2686 bp) adsorbed onto a mica surface in a buffer solution 

containing 50 mM NiCl2. The major grooves (2.2 nm wide) indicated by the gray arrows 

and the minor grooves (1.2 nm wide) indicated by the white arrows along the DNA 

chains were clearly resolved. Figure 1(b) shows an FM-AFM image of bR trimers on the 

cytoplasmic side of a purple membrane patch on a mica substrate in a phosphate buffer 

solution. A two-dimensional (2D) frequency shift (Δf) mapping image (X-Z) on the 

membrane was also shown. 

a) b) 

Figure 1: (a) FM-AFM image of pUC18 plasmid DNA on a mica substrate in 50mM NiCl2 

solution. Image size: 48.4 nm × 20.0 nm. Inset: simulated structural model of DNA taking the tip 

size effect into account. Image size: 10.0 nm × 5.5 nm. (b) FM-AFM image (image size: 29.1 nm 

× 29.1 nm) and 2D frequency shift mapping image (image size: 29.1 nm × 2.5 nm) of a purple 

membrane patch in buffer solution. 

[1] T. Fukuma, K. Kobayashi, K. Matsushige, and H. Yamada. Appl. Phys Lett. 87, 034101 (2005). 

[2] S. Rode, N. Oyabu, K. Kobayashi, H. Yamada, A. Kuhnle. Langmuir 25, 2850 (2009). 

88

Bimodal AFM imaging of antibodies and chaperonins in liquids 

E.T. Herruzo, C. Dietz, J.R. Lozano and R.Garcia 

Instituto de Microelectrónica de Madrid (CSIC), Madrid, Spain 

Fr-1200 

Bimodal AFM is novel probe microscopy method based on the simultaneous excitation of 

the first two flexural modes of the cantilever. The instrument opens up additional 

channels (amplitude and phase of the 2 nd mode) which can be used for imaging with 

enhanced lateral resolution and compositional contrast with respect to amplitude 

modulation AFM. 

Here, we discuss the performance of the Bimodal AFM in water and buffer solutions by 

imaging and resolving the structural components of isolated biomolecules and packed 

protein arrays. Bimodal AFM images of antibodies reveal the subunits in both monomer 

and pentameric forms by applying very low forces. Unprocessed high resolution images 

of GroEL reveal the seven-fold symmetry of the protein. 

We also perform theoretical and numerical simulations to characterize Bimodal AFM 

operation. Our model allows us to study the material contrast sensitivity of the two 

additional channels (amplitude and phase of the 2 nd mode) that can be used for imaging. 

The theoretical approach also allows us to estimate the forces applied on the sample 

during bimodal AFM operation. The calculated forces are small, due to the enhanced 

sensitivity of 2 nd mode phase to detect changes while the cantilever is far away from the 

sample. 

Figure 1 

a) b) 

Figure 2 

Figure 1. Bimodal (a) and topography (b) image of an isolated IgM antibody in water. 

Figure 2. Topography image under Bimodal AFM imaging of GroEl chaperonins in buffer. 

[1] Rodriguez T R and Garcia R 2004 Appl. Phys. Lett. 84 449–51 

[2] Martinez N F, Patil S, Lozano J R and Garcia R 2006, Appl. Phys. Lett. 89 153115–3 

[3] Patil S, Martinez N F, Lozano J R and Garcia R 2007, J. Mol. Recognit. 20 516–23 

[4] Lozano J R and Garcia R 2008 Phys. Rev. Lett,100 076102–4 

[5] N F Martínez et al 2008 Nanotechnology 19 384011 

89

Fr-1220 

Redox-state Dependent Reversible Change of Molecular Ensembles in 

Water Solution by Electrochemical FM-AFM 

Ken-ichi Umeda 1† , Yasuyuki Yokota 2 , and Ken-ichi Fukui 2,3 

1 Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan. 

2 Department of Materials Engineering Science, Osaka University, Osaka, Japan. 

3 PRESTO, Japan Science and Technology Agency, Saitama, Japan. 

Electrochemisty can provide wide range of science and technology because of easy 

control of electrochemical potentials of interfaces and adsorbed molecules, which initiate 

electron transfer and chemical reactions hard to achieve in vacuum. Redox-active 

molecules fixed on the electrode can reversibly change their charges depending on the 

electrode potential, which makes it possible to introduce a point charge at the 

electrode/solution interface. Following the recipe in literature to reduce the deflection 

noise density in liquid-phase measurements, we have developed a frequency-modulation 

AFM applicable in electrochemical environments with controlling the potential of the tip 

and the sample. By using the EC-FM-AFM, we have studied how the charging of the 

molecule fixed at the electrode/solution interface affect the local structure. 

Ferrocenylundecanethiol (FcC11H22SH) molecules were embedded in an n-decanethiol 

(C10H21SH) self-assembled monolayer (SAM) matrix as molecular islands In Figure 1(a), 

the Fc-islands are shown as bright protrusions, whose apparent height differ depending 

on their lateral size (number of involved molecules). By changing the charge of Fcterminal 

groups from Fc 0 to Fc +1 , the apparent height and the lateral size of each Fcisland 

has clearly increased as shown in Figure 1(b). The process was reversible against 

the potential change, and originated from the change in the local charge. Simultaneously 

obtained energy dissipation signal has decreased at the island when the Fc-islands had 

positive charge. These results can be reasonably explained by the formation of ion 

network from Fc + and ClO4 - counter anions supplied from the electrolyte water solution. 

(a) Fc (b) 0 

Fc +1 

Figure 1: In situ EC-FM-AFM images (Δƒ = +528 Hz) of FcC11H22SH islands embedded in 

C10H21SH SAM (200×160 nm 2 50 nm 50 nm 

) at different electrochemical potentials: (a) substrate potential (Es) 

= tip potential (Et) = -0.8 V, (b) Es = Et = -0.4 V vs. Au/AuOx, respectively. The amplitude of 

cantilever vibration was maintained in a feedback loop to be 0.5 nm. 

† 

Present address: Department of Electronic Science and Engineering, Kyoto University, Japan. 

90

Poster 

Session I 

Tuesday, 11 August 

91

P.I-01 

Force and Tunneling Current Measurements on the Semiconductor 

Surface 

Daisuke Sawada, Yoshiaki Sugimoto, Ken-ichi Morita, Masayuki Abe, and Seizo Morita 

Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka, 565-0871, Japan. 

Non-contact atomic force microscopy (NC-AFM) and scanning tunneling microscopy 

(STM) enable us to obtain atomically-resolved information, for example, chemical 

bonding force or local density of state (LDOS). Recently, at the near contact region, the 

drop of the tunneling current was reported using conventional STM [1]. The drop of the 

tunneling current was explained by the chemical bonding formation, however, such 

correlation has not been measured experimentally. We measured the force and the 

tunneling current simultaneously using metal coated Si cantilevers. Here, we report our 

results on both the Si(111)-(7×7) surface and the Ge(111)-c(2×8) surface at room 

temperature using the feedforward technique in order to compensate the thermal drift [2]. 

In constant height simultaneous measurement, atomic image contrast between the 

AFM image and the STM image are different [Fig.1 a), b)]. We obtained FSR-z and It-z 

curves on the adatom of the Ge(111)-c(2×8) surface by measuring Δf-z and -z curves 

[Fig.1 c)]. The drop of It was oabserved at the onset of FSR with decreasing the tip-surface 

distance. The drops were observed on the Ge(111)-c(2×8) surface as well as the Si(111)- 

(7×7) surface [3]. 

A part of this work was supported by Grant-in-Aid for Scientific Research on 

Priority Areas “Nano Materials Science for Atomic Scale Modification” and Global COE 

Program, “Center for Electronic Devices Innovation”. 

Figure 1: Δf image a) and image b) were obtained simultaneously in the constant height 

mode. The sample bias (Vs) is +500 mV. c) FSR-z and It-z curves measured on the Ge adatom 

at Vs= +500 mV. 

[1] P. Jelínek, et al., Phys. Rev. Lett. 101, 176101 (2008). 

[2] M. Abe, et al., Appl. Phys. Lett. 90, 203103 (2007). 

[3] D. Sawada, et al., Appl. Phys. Lett. 94, 173117 (2009). 

92

P.I-02 

Force Map of Atomic Force Microscopy on Si(111)-(5x5)-DAS Surface 

Akira Masago and Masaru Tsukada 

WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 980-8577 Japan 

Recently, lateral force mapping has been performed by atomic force microscopy (AFM) 

on the Si(111)-(7x7)-(Dimer-Adatom-Stacking fault (DAS)) surface, as well as potential 

and vertical force mapping. We believe that they provide us with useful information for 

atomic identification and manipulation. In this study, we simulated force maps along the 

long diagonal direction of the unit cell of the Si(111)-(5x5)-DAS surface using the 

density-functional based tight-binding (DFTB) calculation. As a result, we obtained force 

maps shown in Fig. 1, using a Si4H9 cluster tip. In the vertical force map, the small peaks 

located at the rest atoms (Rs) as well as the large peaks at the adatoms (Ad). Moreover, 

the plateaus also exist at bridge site (Br) of the adatoms out of the scan trajectory. In the 

lateral force maps, we can see paired peaks located at the adatoms and rest atoms. These 

characters must be related with the atomic configuration of the tip apex. In our 

presentation, we will talk about the relation between remarkable characters that present 

on the force maps and various configurations of the tip apex. 

Figure 1: Vertical and lateral force maps when the tip scans along a long diagonal line of a unit 

cell of the Si(001)-(5x5)-DAS surface as well as side and top views of the surface. All circles 

denote Si atoms, where open and fill circles denote adatoms and rest atoms, respectively. In 

particular, open circles written in bold face are adatoms on the scan trajectory. 

93

From non-contact to atomic scale contact between a Si tip and a Si 

surface analyzed using an nc-AFM and nc-AFS based instrument 

P.I-03 

Toyoko Arai 1 , Kosei Kiyohara 1 , Taiki Sato 1 , Shugaku Kushida 2 and Masahiko Tomitori 2 

1 Graduate School of Natural science & Technology, Kanazawa University, Kanazawa, Ishikawa, Japan 

2 School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa Japan 

The scanning probe microscopy (SPM) is a powerful tool to observe a sample surface 

with atomic resolution as well as spectroscopic measurements and atom/molecule 

manipulation. Since the advent of SPM, we are able to bring an atomically sharpened tip 

very close to a sample in a well-controlled manner, in particular, by non-contact atomic 

force microscopy (nc-AFM); the force interaction detected by nc-AFM changes so 

drastically at atomically close separations that the precise control of separation is 

performed. The quantum mechanical properties become prominent at those distances 

between a tip and a sample; chemical covalent bonding is formed at less than 1 nm, the 

tunneling barrier between them collapses, and at closer distances, an atomically necking 

can be shaped and quantized conductance comes up through atomically confined 

channels or intermediate electronic states in between. The quantized phenomena at the 

point contact have attracted much interest, including its formation process from noncontact 

through pseudo-contact to contact. Not only the force interaction, but also the 

electric conductance properties can be evaluated using an instrument based on nc-AFM 

combined with spectroscopic methods at those separations, i.e., bias-voltage non-contact 

atomic force spectroscopy (nc-AFS) with the ability to measure electric current with 

respect to bias voltage between a tip and a sample [1]. From a viewpoint of application, 

contact formation between two pieces of condensed matter is crucial to fabricate novel 

nanoscale devices. Here we focus on Si-Si contact and non-contact states analyzed by an 

nc-AFM and nc-AFS based instrument. Although silicon-silicon contacts sounds very 

important in industries and various types of Si nanowires have been synthesized, there are 

few reports on their nanoscale electromechanical properties. 

Experiments were conducted using a home-made UHV-AFM/AFS instrument with a 

B-doped Si piezoresistive cantilever having a [001]-oriented Si for samples of n- and ptype 

Si(111). After cleaning the tip and the sample by heating in UHV, we took nc-AFM 

images simultaneously with current, averaged over a cantilever oscillation cycle, and 

damping with changing bias voltage, while taking spectroscopic curves of frequency shift 

current and damping versus bias voltage or tip-sample separation. By slowly approaching 

and retracting with compensation of z-direction thermal drift, the current-separation 

curves with a good S/N ratio exhibited features from tunneling regime to saturation 

toward tunneling barrier collapse, leading to chemical bond formation. The damping also 

exhibited curious features possibly due to charge change around the tip and the sample. 

For Si point contacts current-voltage curves showed p-p or p-n junction characteristics 

with staircase behaviors. The details and discussion will be presented. 

1. [1] T. Arai and M. Tomitori: Phys. 

Rev. B 73 (2006) 073307. 

94

P.I-04 

Improved atomic-scale contrast via bimodal dynamic force microscopy 



We extend multi-frequency AFM to atomically resolved frequency-modulation 

dynamic force microscopy and demonstrate a further improvement of spatial resolution in 

ultra-high vacuum [1]. The first and second flexural resonance modes of a commercially 

available Si cantilever are simultaneously self-excited with given amplitudes, and the 

resonance frequency shifts (Δf1st and Δf2nd) are demodulated by two phase-locked loop 

circuits (Nanonis: Dual-OC4). The combination of sub-angstrom amplitude oscillation 

A2nd at the second resonance with the commonly used large amplitude oscillation A1st at 

the first resonance enables higher resolution imaging at closer tip-sample distances while 

avoiding atomic jump-to-contact instabilities, which are more likely at such distances 

during small amplitude operation with a single mode [2-4]. 

Figure 1 shows a series of simultaneously recorded Δf1st and Δf2nd maps of KBr(001), 

obtained with A1st=16 nm and A2nd=50 pm at decreasing tip-sample distances in the 

attractive region, recorded in the quasi-constant height mode. Being more sensitive to the 

short-range interaction, Δf2nd exhibits a stronger distance dependence and contrast than 

Δf1st at short distances. Although A2nd was much smaller then the width of the measured 

force minimum, the signal-to-noise in the Δf2nd map was higher than in the Δf1st map at 

close tip-sample distances [(e) and (f)]. The enhanced sensitivity to the short-range 

interaction could even reveal tip and/or sample deformations induced by the interaction 

force. 

Figure 1: A series of simultaneously recorded Δf1st and Δf2nd maps at decreasing tip-sample 

distances (a – f). The first and second resonance frequencies are 154021 Hz and 960874 Hz, and 

the Q factors and amplitudes are 31059 and 6246, and A1st=16 nm and A2nd=50 pm, respectively. 

[1] S. Kawai et al., submitted. 

[2] F. J. Giessibl et al., Science 289, 422 (2000). 


[4] S. Kawai and H. Kawakatsu, Appl. Phys. Lett. 88, 133103 (2006). 

95

Static cantilever deflection in dynamic force microscopy 



P.I-05 

So far, the influence of the time-averaged cantilever deflection in dynamic force 

microscopy (DFM) and spectroscopy [1] has been assumed negligibly small or constant, 

or else regarded as the source of jump-to-contact instabilities. But in fact, for a given tipsample 

distance of closest approach, the static deflection increases with decreasing 

oscillation amplitude. As a consequence, small-amplitude DFM is able to simultaneously 

detect the influence of atomic-scale interaction forces on time-averaged, as well as 

dynamic measured quantities. The use of higher resonances [2,3] is well-suited for this 

comparison because a typical static stiffness kc ~ 30 N/m can cause a measurable timeaveraged 

deflection. Nevertheless kc is still high enough to avoid cantilever jump-tocontact 

instabilities when a surface with a low reactivity is scanned with a sharp Si tip [4] 

We theoretically and experimentally studied the effects of the time-averaged 

deflection in DFM. Figure 1(a) and 1(b) shows a series of frequency shift and static 

deflection vs. distance curves measured using different amplitudes A2nd of the second 

flexural mode above a maximum of the topographic image of KBr(001). Figure 1(c) 

shows force vs. distance curves with and without compensation of the static deflection. It 

is found that the static deflection affects not only the Z-distance scale, 

but also the 

converted force. Force curves extracted from Δf2nd(Z) measured with different A2nd 

coincide if shifted along Z and exhibit a wiggle which is likely due to a sideways 

displacement of the tip apex towards a nearby counterion on the sample surface [1]. 

Figure 1: A series of (a) frequency shift and (b) static deflection vs. distance curves. (c) Force vs. 

distance curves with (Zc) and without (Z’c) compensation of the static deflection. 

[1] A. Schirmeisen et al., Phys. Rev. Lett. 97, 136001 (2007). 


[3] S. Kawai and H. Kawakatsu, Appl. Phys. Lett. 88, 133103 (2006) 

[4] S. Kawai and H. Kawakatsu, Phys. Rev. B 79, 115440 (2009). 

96

P.I-06 

Resonance frequency shift due to tip-sample interaction in the thermal 

oscillations regime 

Giovanna Malegori, Gabriele Ferrini 

Dipartimento di Matematica e Fisica, Università Cattolica, Brescia, Italy 

We present results on the interaction of a cantilever in the thermal oscillations regime 

with the force gradients near various kind of surfaces. As is well known, the power 

density spectrum of a cantilever freely oscillating in the absence of external modulation 

shows the thermal amplitude and resonance frequency of its flexural modes. As the tip 

approaches a surface, a frequency shift in the amplitude and resonance frequency of the 

thermally excited flexural modes is measured as a function of the tip-sample separation, 

until jump-to-contact sets in. After jump-to-contact, the power density spectrum of the 

cantilever fluctuations changes due to the fact it has a supported end. A comparison with 

available models permits to identify the flexural modes in the two situations (we detect 

four flexural modes for the free end cantilever and two for the supported end cantilever) 

and to extract information about the interaction force gradients. The mean vibration 

amplitude in the various flexural modes is in the range of 10-100 pm at room 

temperature, according to the stiffness of the cantilever. Finally, we describe the 

acquisition techniques and background requirements for the instrumentation. 

97

Influence of thermal noise on measurements of 

chemical bonds in UHV-AFM 

Peter M. Hoffmann 

Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201 

P.I-07 

Ultra-high vacuum based AFM has been repeatedly shown to provide high resolution 

measurements of forces and force gradients associated with chemical bonds 1-5 . However, 

the bond parameters, such as bond length and energies, have varied between 

measurements. One theory put forward for these discrepancies has been the influence of 

thermal noise on measurements performed at room temperature. In FM-AFM it was 

originally found that bond force curves seem broadened when measured at room 

temperature 1 , and theoretically expected bond lengths were only recovered when 

measurements were obtained at low temperature 2 . On the other hand, AM-AFM 

performed at small amplitudes found no such broadening at room temperature 3 . More 

recent measurements using FM AFM at room temperature, however, also seem to show 

shorter interaction lengths 4,5 . What, if any, is the influence of cantilever thermal noise on 

measured interaction lengths? We present a simulation study of the influence of thermal 

noise on measurements of interaction forces using FM or AM AFM. 

[1] M. Guggisberg, et al., Phys. Rev. B 61, 11151 (2000). 

[2] M. A. Lantz, et al., Science 291, 2580 (2001). 

[3] P.M. Hoffmann, et al.. Proc. Royal Soc. Lond. 457, 1161-1174 (2001). 

[4] Y. Sugimoto et al., Phys. Rev. B 77, 195424 (2008). 

[5] K. Ruschmeier et al., Phys. Rev. Lett. 101, 156102 (2008) 

98

P.I-08 

Atomic force microscope cantilever resonance frequency shift based 

thermal metrology 

Arvind Narayanaswamy 1 , Carlo Canetta 1 , and Ning Gu 2 

1 Department of Mechanical Engineering, Columbia University, New York, USA. 

2 Department of Electrical Engineering, Columbia University, New York, USA. 

The atomic force microscope (AFM) is now an indispensable tool not only in obtaining 

topographical images of the surfaces of physical objects but also measuring the forces, 

such as van der Waals and Casimir, between two objects, one of which is the tip of the 

AFM cantilever or a microsphere attached to the cantilever, and the other is a substrate 

mounted on a translation stage. We have used a bi-material AFM cantilever to measure 

the radiative transfer, instead of force, between a microsphere attached to a cantilever and 

a substrate, thereby extending the capabilities of a conventional AFM with minor 

modifications. Unlike force measurement, which can use the static deflection of the 

cantilever or the frequency shift of a resonance mode, the heat transfer can be measured 

only through the static deflection of the cantilever. However, with cantilevers to which 

microspheres are attached to the tip, the flexural as well as torsional modes of the 

cantilever exhibit a frequency shift due to the temperature changes of the cantilever that 

is independent of the variation of material properties with temperature. The frequency 

shift is due to the change in curvature of the cantilever, in this case due to temperature 

changes, and is more pronounced for higher order modes compared to the fundamental 

flexural resonance mode. Though not as sensitive a technique as measuring temperature 

changes via static deflection, the resonance frequency based technique is more robust and 

can be calibrated to measure the absolute temperature as opposed to temperature shifts 

alone. While the frequency shift of the first flexural mode is small enough not to affect 

current non-contact force measurement techniques, it could affect force detection based 

on higher order modes. 

99

P.I-09 

Contact potential difference on the atomic-scale probed by 

Kelvin Probe Force Microscopy: an imaging scenario 

Laurent Nony 1 , Adam Foster 2 , Franck Bocquet 1 , and Christian Loppacher 1 

1 

Aix-Marseille Université, IM2NP, Av. Escadrille Normandie-Niemen, F-13397 Marseille and CNRS, IM2NP (UMR 

6242), Marseille-Toulon, France 

2 

Department of Physics, Tampere University of Technology, 

P.O. Box 692 FIN-33101 Tampere, Finland 

A fully numerical analysis of the origin of the atomic-scale contrast in Kelvin probe force 

microscopy (KPFM) is presented. The numerical implementation mimics recent experimental 

results on the (001) surface of a bulk alkali halide single crystal for which a simultaneous 

topographical and Kelvin, so-called Contact Potential Difference (CPD), atomic-scale contrast 

had been reported [1]. In this work, we have combined atomistic simulations of the tip-sample 

force field with our non-contact AFM/KPFM simulator [2] to compute topographical and CPD 

images. The force field notably includes the required short-range bias voltage dependence to 

account for the CPD atomic-scale contrast. The sample is a NaCl(001) single crystal. The 

atomistic simulations have been performed by means of the code SCIFI [3]. The simulator has 

been used in the Frequency-Modulation KPFM operating mode. The tip consists of a spherical 

metallic cap within which a 4x4x4 NaCl cluster with the [111] direction pointing towards the 

surface is partly embedded. The sample consists of a 10x10x4 NaCl slab embedded within a 

semi-infinite continuous medium merely described by its dielectric constant. The sample, with a 

macroscopic height (several millimeters), lies on a metallic counter-electrode that is biased with 

respect to the tip. Beyond the short-range chemical and electrostatic forces computed with SCIFI, 

we have included a usual Van der Waals long-range term and a less usual, although fundamental, 

long-range electrostatic interaction. This term mimics the weak capacitive interaction between tip 

and sample holders and is necessary to describe the behavior of the CPD with the distance. 

Figs.1a and b show that the simulator is able to account for the simultaneous topographical and 

CPD atomic-scale contrast, respectively. The occurrence of such a contrast is intricately 

connected to the dynamic polarization of the ions of the slab triggered by the modulation of the 

bias voltage, unless otherwise no Kelvin contrast is measured. The nc-AFM/KPFM simulator is a 

tool which helps in interpreting the experimental data quantitatively. 

References : 

[1]- F. Bocquet et al., Phys. Rev. B 

78, 035410 (2008) 

[2]- L. Kantorovich et al., Surf. Sci. 

445, 283 (2000) 

[3]- L. Nony et al., Phys. Rev. B 74, 

235439 (2006); L. Nony et al., 

accepted in Nanotechnology 

Fig.1a- Topography channel 

measured at 0.45nm to the 

surface: the vertical contrast is 

40pm 

100 

Fig.1b- simultaneously 

acquired CPD channel: The 

vertical contrast is 0.6V

Self-assembled Boronitride Nanomesh on Rh(111) 

Investigated by Means of Kelvin Probe Force Microscopy 

P.I-10 

Sascha Koch 1 , Markus Langer 1 , Jorge Lobo-Checa 1,3 , Thomas Brugger 2 , Shigeki 

Kawai 1 , Bartosz Such 1 , Ernst Meyer 1 and Thilo Glatzel 1 

1 Department of Physics, University of Basel, 4056 Basel, Switzerland 

2 Department of Physics, University of Zurich, 8006 Zurich, Switzerland 

3 Centre d'Investigaciò en Nanociència i Nanotecnologia (CIN2), Campus Universitat Autònoma de 

Barcelona, Spain 

By high temperature exposure of borazine [(HBNH)3], a self-assembled hexagonal 

nanomesh with a periodicity of about 3nm and a hole size of 2nm is formed on Rh(111) 

under UHV conditions [1]. The stable and periodic structure is perfectly suitable for 

trapping single molecules at room temperature [2]. The determination of local work 

function variations is a major requirement to understand the process of molecular 

adsorption. NC-AFM combined with Kelvin probe force microscopy (KPFM) enables 

imaging of the surface and simultaneous detection of the work function map with subnanometer 

resolution [3]. 

Figure 1(a) shows the topography signal of the nanomesh which is in good agreement 

with previous STM results [1,2,4]. The Rh(111) surface is found to be completely 

covered with the mesh. Figure 1(b) shows the simultaneously obtained LCPD signal of 

this superstructure clearly resolving a work function difference of the structure. Here a 

variation of the LCPD of approximately 600mV was detected. 

Figure 1: (a) AFM image of the bn-nanomesh (20x20nm 2 ). Parameters: 

Δf=-35Hz, A=4nm, f0=153kHz; Δz=650pm. (b) Simultaneously measured 

LCPD image. ΔLCPD=600mV, VAC=500mV, f1≈fAC=954kHz. 

[1] M.Corso, W. Auwärter, M. Muntwiler, A. Tamai, T. Greber, J. Osterwalder, Science 303, 217 (2004) 

[2] H. Dil, J. Lobo-Checa, R. Laskowski, et al., Science 319, 1824 (2008) 

[3] Th. Glatzel, L. Zimmerli, S. Koch, S. Kawai, E. Meyer; Appl. Phys. Lett., 94, 3 (2009) 

[4] S. Berner, M. Corso, R. Widmer et al., Ang. Chem. Int. Ed. 46, 5115 (2007) 

101

Kelvin probe force microscopy in application to organic thin films: 

P.I-11 

frequency modulation, amplitude modulation, and hover mode KPFM 

Brad Moores 1 , Francis Hane 2 , Lukas Eng 3 , and Zoya Leonenko 1,2 

1 Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada 

2 Department of Biology, University of Waterloo, Waterloo, Canada 

3 Institute of Applied Photophysics, Technical University of Dresden, Dresden, Germany 

We applied Kelvin probe force microscopy (KPFM) to visualize the lateral surface 

potential distribution in thiol self-assembled monolayers and lipid-protein films. We have 

shown earlier (Leonenko, et al. Biophys. J. 2007) that function of Bovine Lipid Extract 

Surfactant (BLES) is related to the specific molecular architecture of surfactant films. 

Defined molecular arrangement of the lipids and proteins of the surfactant film give rise 

to a local highly variable electrical surface potential of the interface. In this work the 

resolution of frequency modulation (FM-KPFM), amplitude modulation (AM-KPFM) 

and hover (HM-KPFM) modes were compared. At larger scale and larger surface 

potential deviations all modes give high resolution images. At smaller scans and smaller 

differences in surface potential FM-KPFM mode gives superior resolution, and therefore 

is preferable for imaging lipid- and lipid-protein films. The response and sensitivity of 

KPFM modes was addressed with the help of force measurements. 

102

P.I-12 

Resolution enhanced multifrequency electrostatic force microscopy 

under ambient conditions 

X. D. Ding 1 , J. B. Xu 2 , and J. X. Zhang 1 

1 State Key Laboratory of Optoelectronic Materials and Technologies, and School of Physics Science & 

Engineering, Sun Yat-sen University, Guangzhou 510275, China 

2 Department of Electronic Engineering, and Materials Science and Technology Research Center, The 

Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China. 

Electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM) 

are widely used to study the electrical and electrochemical characteristics of a variety of 

material. The lateral resolution for EFM ia better than 10~20nm under vacuum conditions 

In contrast, the lateral resolution reported in literature is only 100 nm or so under ambient 

conditions. Though suffering from strong mechanical non-linearity of repulsive tip– 

sample contact, multifrequency method has been introduced to EFM recently[1]. 

Here, we report an extension of multifrequency AFM with enhanced resolution to 

measure electrostatic force under ambient conditions[2]. The first eigenmode of a 

cantilever is used for topography imaging, while the third eigenmode is resonantly 

excitated with a sinusoidal modulation voltage applied on tip to measure electrostatic 

force in lift mode. Figure 1 shows the images for a thermally evaporated aluminum (Al) 

film on Si(111). Due to the surface potential variation of the sample, the EFM image in 

figure 1(b) shows a well reproduced contrast different from its corresponding topographic 

image in figure 1(a). The lateral resolution is better than 15nm determined from the line 

profile in figure 1(c). The enhancement of resolution is ascribed to the suppress of the 

cantilever-sample interactions and the increase of the tip-sample interactions due to the 

use of the third eigenmode of the probe. 

80nm 

30 50 70 

Position, nm 

(a) (b) (c) 

Figure 1: Experimental results of the multifrequency EFM for Al film on Si(111) under ambient 

conditions. (a) Topography image. (b) EFM Image, and (c) The line profile along the arrow in (b) 

[1] R. W. Stark, N. Naujoks, and A. Stemmer, Nanotechnology 18, 065502 (2007). 

[2] X. D. Ding, C. Li, R. Y. Zeng, J. An, and J. B. Xu, Appl. Phys. Lett. (To be published) 

(X. D. Ding, Category 7-Kelvin probe microscopy is fitted and an Oral presentation is preferred) 

103 

Electrostatic Force, a.u. 

1.5 

1.0 

0.5 

10-15nm

P.I-13 

Deconvolution and Tip Geometry Effects in Atomic- and Nanoscale Kelvin probe 


George Elias 1 , Yossi Rosenwaks 1 , Amir Boag 1 , Ernst Meyer 2 , and Thilo Glatzel 2 

1 Dept. of Physical Electronics, Tel-Aviv University, Tel Aviv 69978, Israel 

2 Dept. of Physics, University of Basel, Klingelbergstr. 82, 4056 Basel, Switzerland 

In Kelvin probe force microscopy (KPFM) the long range electrostatic forces between the 

tip and the surface prevents quantitative measurement of nanostructures; however this 

can become feasible by developing appropriate deconvolution algorithms that restore the 

actual sample work function. We present such novel algorithms and methods that enable 

us to restore measurements conducted at tip-sample distances below 1 nm, while taking 

into account also the measured topography. Fitting the restored images with KPFM 

measurements of samples with well defined work function values has allowed us to 

extract the measuring tip geometry and validate our deconvolution methods. 

The three dimensional potential of the tip-sample system is calculated using an 

integral equation based boundary element method, combined with modeling the sample 

by an equivalent dipole-layer and image-charge model. The tip is modeled using MSC 

Patran finite element mesh, to create a high density mesh on the tip apex and a lower 

density mesh far from the sample as shown in Figure 1 (left). The middle figure shows a 

measured UHV-KPFM image of NaCl thin film grown on Cu (111) and a comparison 

with convolutions performed with 3 different tip apex radii (right). The excellent 

agreement obtained for a tip apex of 10nm allows to estimate the tip apex geometry, and 

helps to validate our convolution algorithms. Implications for real tip shapes (nanotips) 

and atomic resolution imaging is demonstrated and discussed 

Figure 1: (left) Full tip geometry mesh and tip apex mesh ; (middle) a KPFM measurement of 

NaCl thin films grown on Cu(111); (right) a comparison between the measured KPFM line in the 

middle image and convolutions performed for 3 tip apex radii (half opening angle of 17.5º) of 3, 

6, and 10 nm. 

104

P.I-14 

Kelvin Force Microscopy Dynamic Behavior and Noise Propagation 

Heinrich Diesinger, Dominique Deresmes, Jean-Philippe Nys, and Thierry Mélin 

Institut d’Electronique, Microelectronique et Nanotechnologie, CNRS UMR 8520, Department 

ISEN,Avenue Henri Poincaré, 59652 Villeneuve d’Ascq, France 

The bandwidth of scanning probe control loops limits the sampling rate in data 

acquisition. In this work, the dynamic behavior of amplitude detection (AM) and 

frequency detection (FM) Kelvin force microscopy (KFM) setups is analyzed and 

optimized. Since enhanced bandwidth alone would increase speed at the cost of tolerating 

more noise, the origin of noise and its propagation within the control loops are studied in 

parallel. 

Laser Diode Photodetector 

F N = 4γk B T 

CPD 

V PD 

V PD, N = 10 μV/sqrt(Hz) 

In 

Lock-in 

Osc 

V 

bias, AC 

fres2 X 

PI Amplifier 

Kelvin Controller 

+ 

Σ = 

+ 

V Kelvin 

open closed 

Figure 1: Setup of the Kelvin control loop of an AM-KFM, consisting of a lock-in amplifier 

exciting the probe electrostatically at its second resonance, and a PI error amplifier to close the 

feedback loop and to apply the Kelvin voltage to the probe. The loop can be opened. Main noise 

sources are the thermal probe excitation force and white noise at the output of the photodetector. 

Fig. 1 shows the Kelvin control loop of an AM-KFM in ultrahigh vacuum, using the 

second cantilever resonance for KFM while distance control is based on the first, similar 

to the setup demonstrated by Kikukawa et al.[1]. The noise power spectral density of the 

Kelvin output signal can be modeled after the transfer functions of the different stages 

have been measured in open loop configuration. A benchmark criterium for comparing 

hardware with respect to noise is issued. An FM KFM close to the configuration 

suggested by Kitamura [2] is also analyzed. Advantages and drawbacks of both methods 

in terms of bandwidth and signal to noise are discussed. 

[1] A. Kikukawa, S. Hosaka, and R. Imura. Appl. Phys. Lett. 66, 3510 (1995). 

[2] S. Kitamura and M. Iwatsuki. Appl. Phys. Lett. 72, 3154 (1998) 

105

Charge transfer from doped silicon nanocrystals 

P.I-15 

Łukasz BOROWIK 1 , Thuat NGUYEN-TRAN 2 , Pere ROCA i CABARROCAS 2 , Koku 

KUSIAKU 1 , Didier THERON 1 , Heinrich DIESINGER 1 , Dominique DEREMES 1 , and 

Thierry MELIN 1 

1 

Institut d’Electronique, de Microélectronique et de Nanotechnologie, CNRS-UMR 8520, Av . Poincaré, 

BP 60069, 59652 Villeneuve d’Ascq, France 

2 

Laboratoire de Physique des Interfaces et des Couches Minces, CNRS-UMR 7647, Ecole Polytechnique 

91128 Palaiseau, France 

We present ultra-high vacuum (UHV) atomic force experiments performed on doped 

silicon nanocrystals fabricated by plasma enhanced chemical vapour deposition. The aim 

of this work is to study the doping properties and charge transfers from doped 

nanocrystals using UHV amplitude modulation Kelvin force microscopy (AM-KFM). 

The doping properties of hydrogen passivated nanocrystals are studied by monitoring the 

nanocrystal surface potential VS as a function of the nanocrystal and substrate doping, 

and also as a function of the nanocrystal size. The case of intrinsic nanocrystals is 

illustrated in Figure 1, in which the surface potential VS of the nanocrystals is plotted as a 

function of their height, showing - in average - positive or negative charge transfer from 

the p-doped and n-doped substrate, together with strong potential fluctuations attributed 

to the variation of the nanocrystal surface states. This situation is then compared to the 

case of n-doped nanocrystals, for which much lower potential fluctuations can be 

observed, and for which the nanocrystal surface potential VS is found almost independent 

of the doping level. These two effects are understood as stemming from the doping of the 

nanocrystal, which provides the necessary charge to compensate for the nanocrystal 

surface states, and induce a charge transfer to the substrate. The interpretation of the 

charge transfer equilibrium will be detailed quantitatively[1], using numerical simulations 

of the KFM signals taking into account capacitance averaging effects known to occur in 

KFM [2]. It will be shown that the charge transfer is enhanced due to the quantum 

confinement in nanocrystals with size

Open source scanning probe microscopy control and data analysis 

Percy Zahl 1 

software package Gxsm. 

1 Brookhaven National Laboratory, Center for Functional Nanomaterials, Upton NY 11973, USA 

P.I-16 

Gxsm 1 is a full featured and modern scanning probe microscopy (SPM) software. It can 

be used both in stand alone mode for powerful image processing and analysis and 

connected to an instrument operating many different flavors of SPM, e.g., scanning 

tunneling microscopy (STM) and atomic force microscopy (AFM) or in general twodimensional 

multi-channel data acquisition instruments. The Gxsm core can handle 

different data types, e.g., integer and floating point numbers. An easily extendable plugin 

architecture provides many image analysis and manipulation functions. A powerful 

digital signal processor (DSP) subsystem runs the feedback loop, does optional adaptive 

real-time signal filtering, generates the scanning signals and acquires all the data during 

SPM measurements. We will show lastest results and demonstrate the performance of the 

new SignalRanger Mark2 and Analog A810 now supported by GXSM. The 

programmable Gxsm vector probe engine (real-time, DSP based) performs virtually any 

thinkable spectroscopy and manipulation task, such as scanning tunneling spectroscopy 

(STS) or tip formation. The Gxsm software is released under the GNU general public 

license (GPL) and can be obtained via the Internet. 

Visit and follow the Gxsm home page for further information: 

1 Homepage location: http://gxsm.sourceforge.net. 

107

2 nd generation Dynamic Nanostencil AFM/DFM/STM 

for in-situ (UHV) resistless patterning of nanostructures 

Percy Zahl 1 , Peter Sutter 1 

1 Brookhaven National Laboratory, Center for Functional Nanomaterials, Upton NY 11973, USA 

P.I-17 

The development and construction of the 2 nd generation Nanostencil, which will be an 

upgrade of the original and worldwide unique 1 st all-in-one Nanostencil as build at IBM 

Zurich Research Laboratory 1,2 . This Nanostencil instrument combines the shadow mask 

stencil method with an versatile scanning probe microscope and allows in-situ creation 

and inspection of even arbitrary single nanostructures down to 30nm as demonstrated at 

IBM. 

With the new design of the 2 nd generation Stencil a set of optimizations and partial 

redesigns will be incorporated. Nevertheless, this new CFN Nanostencil will be user 

accessible. 

The Nanostencil technique integrates a system for in-situ nano structuring and 

Atomic/Dynamic Force Microscopy (AFM/DFM) and Scanning Tunneling Microscopy 

(STM) capability for in-situ structure analysis with atomic resolution capability but also 

wide (80µm for the 2 nd generation) scan range. In contrast to lithography methods, this is 

a direct writing or deposition method and no resist removal or etching steps are involved, 

allowing to make structures from any material which can be evaporated in UHV. Thus 

advanced sensitive or functional materials of an wide range (including metals, insulators, 

magnetic materials or even organic materials) can be used for patterning. 

The Scanning Probe Microscopy capabilities allow imaging and optional manipulation of 

the deposited nanostructures/atoms and thus extends structure tune-ups down to the 

atomic scale. 

The 2 nd generation Nanostencil is currently in development at the CFN. It is expected to 

deliver similar or better stencil performance as the IBM-Stencil and will add more 

versality and a calibrated high precision scanning table with up to 80µm scan range. It 

will also provide a high resolution scanner (piezo tube style) for reaching atomic 

resolution. Optimized optical access for coarse alignments (Long Distance Microscope 

with 3µm resolution) while providing simultaneous access for deposition is planned. 

1 

All-in-one static and dynamic nanostencil atomic force microscopy/scanning tunneling microscopy 

system, P. Zahl, M. Bammerlin, G. Meyer and R.R. Schlittler, Rev. Sci. Instrum. 76, 0230707 (2005) 

2 

Fabrication of ultrathin magnetic structures by nanostencil lithography in dynamic mode, L. Gross, R.R. 

Schlittler, G. Meyer, A. Vanhaverbeke and R. Allenspach, Appl. Phys. Lett. 90, 093121 (2007) 

108

P.I-18 

Design of a Variable Temperature Variable Magnetic Field Noncontact 

Scanning Force Microscope for the Characterization of Nanoscale 

Electronic and Magnetic Phenomena 

Peter Staffier 1 , Marcus Liebmann 1 , Jens Falter 1 , Nicolas Pilet 1 , Charles Ahn 2 , and Udo 

D. Schwarz 1 

1 



2 

Department of Applied Physics and Center for Research on Interface Structures and Phenomena 


In thin film manganese oxides variations in the electric charge carrier density can result 

in increased conductivity, magnetic domain formation, and lattice distortions due to 

strong electron correlation effects. We intend to characterize the length scales at which 

the electronic, magnetic, and structural properties of thin films of La1-xSrxMnO3 remain 

correlated by using localized electrostatic fields to modulate the electric charge density 

while applying noncontact scanning force microscopy methods to observe the resulting 

phase changes. Since manganese oxides are most sensitive to electrostatic perturbation 

near their phase transition temperatures Tc, a critical part of the planned experiments will 

be to measure samples at various temperatures. 

For that purpose, we have developed a new ultrahigh vacuum variable temperature 

noncontact scanning force microscope (NC-AFM). The requirement to run experiments 

at distinct, stable temperatures shortly below and above Tc has been addressed by 

choosing a low vibration flow cryostat for cooling. Thermal gradients are minimized by 

cooling the entire microscope, in contrast to most commercially available variable 

temperature NC-AFMs. In addition, an electromagnet mounted to the vacuum system 

supplies magnetic fields up to 180 mT for in-field magnetic force measurements. A 

quartz microbalance and two evaporators allow for the preparation of multilayer 

magnetic force sensors in-situ. Both cantilever and sample stages permit the exchange of 

force sensors and samples in-situ with the microscope at low temperatures. An x-y 

translation stage provides up to 4 mm × 4 mm of course motion in the horizontal plane so 

that we may measure at various positions on the sample. We will present the 

microscope’s design, initial measurements in topographical and magnetic operational 

modes, and details on some of the further planned experiments. 

109

An Active Q Control System in Scanning Force Microscopy 

Jeehoon Kim 1 , Martin Zech 1 , and J. E. Hoffman 1 

1 Department of Physics, Harvard University, Cambridge MA, USA 

P.I-19 

We have developed a high vacuum, cryogenic scanning force microscope with a fiber 

optic interferometer detection system. The microscope has several features: (1) flexibility 

to employ either a horizontal cantilever or a vertical cantilever; (2) rigidity of design to 

allow DC cantilever deflection detection as small as 1 picometer; (3) an x-y walker to 

position the tip above interesting features within a 3 mm × 3 mm area. 

We have also developed an active quality factor (Q) control system by employing a 

phase shifter using capacitive coupling. The active Q control system allows Q reduction 

by a factor of 60 without sacrificing signal to noise ratio. This active Q control system is 

essential for non-contact force microscopy with a vertical cantilever in order to increase 

both a force resolution and spatial resolution. The Q control system could also be used in 

either vertical or horizontal cantilever mode to increase scanning speed, or to employ 

amplitude modulation mode scanning in a vacuum or low temperature environment. 

a) b) 

Figure 1: (a) The home-built high vacuum, cryogenic magnetic force microscope and (b) 

Schematic of the active Q system, showing phase shifter and capacitive coupling. 

110

P.I-20 

Besocke style quartz tuning fork FM-AFM/STM for use in UHV and 

low temperatures 

Shawn M. Huston 1 , Rachel T. Port 1 , Katie M. Andrews 1 , and Thomas P. Pearl 1 

1 Department of Physics, North Carolina State University, Raleigh, USA 

The design and operation of a Besocke-style scanning probe microscope with both 

frequency modulated atomic force and scanning tunneling microscopy capabilities will be 

presented. This instrument has been optimized for use at low temperatures, either with 

helium or nitrogen cooling, in ultrahigh vacuum. FM-AFM is performed via a quartz 

crystal tuning fork in the qPlus sensor configuration. Cooling of the microscope is 

achieved through the use of a top-loaded bath cryostat that cools a pair of radiation 

shields which house the spring-suspended microscope assembly. This Besocke-style 

microscope is designed to record tunneling current and resonance frequency shift for a 

conductive tip mounted on the free prong of the tuning fork simultaneously Single 

molecule images of pentacene on Ag(111) at ~5 K recorded in both NC-AFM and STM 

modes will be proffered as a testament to the microscope’s effectiveness. 

111

P.I-21 

Design of a Low Temperature Noncontact Atomic Force Microscope 

Combined with a Field Ion Microscope 

J. Falter 1 , D.-A. Braun 1 , H. Hölscher 2 , U. D. Schwarz 3 , A. Schirmeisen 1 , and H. Fuchs 1 

1 CeNTech Center for Nanotechnology and Institute of Physics, University of Münster, Germany 

2 IMT, Forschungszentrum Karlsruhe, Germany 

3 Department of Mechanical Engineering, Yale University, New Haven, USA 

Non-contact atomic force microscopy has become a standard tool for imaging surfaces 

with atomic resolution. The underlying contrast mechanism is influenced by both 

interaction partners, the sample as well as the tip. Theoretical simulations of the force 

interaction allow a deeper insight in the contrast mechanisms but require information 

about the exact position of all atoms of sample and the tip. A method that is able to 

determine the configuration of the probing tip with atomic precision is the field ion 

microscope (FIM). 

We present a home-built low temperature ultra high vacuum (UHV) system that 

combines these two microscopy techniques. The design of the AFM has been proven to 

operate in UHV at low temperature and features a high mechanical stability [1]. The 

original design was modified to use piezoelectric tuning forks as force sensors, with a 

glued-on tungsten wire, prepared by the double lamella etching technique [2] (Figure 1a). 

For stable oscillation, the tuning fork is excited electronically [3] in the frequency 

modulation mode. Our force sensors have been successfully employed in the AFM as 

well as the FIM. Figure 1b shows a FIM image of a tuning fork tungsten tip allowing the 

atom-by-atom reconstruction of the tip apex demonstrated in Figure 1c. 

a) b) c) 

Figure 1: a) Image of the tuning fork force sensor with glued-on tungsten wire. b) FIM image of 

a tuning fork tungsten tip, indicating the different crystallographic axis. A bright spot in the FIM 

image corresponds to a tip apex atom. c) Atom-by-atom reconstruction of the whole tip apex. 

[1] B. Albers et al, Rev. Sci. Instrum. 79 033704 (2008). 

[2] M. Kulawik et al, Rev. Sci. Instrum. 74, 1027 (2002) 

[3] J. Jersch et al, Rev. Sci. Instrum. 77, 083701 (2006) 

112

P.I-22 

A homebuilt low-temperature STM / tuning fork AFM combination 

Manfred Lange 1 , Johannes Schaffert 1 , Nikolai Wintjes 1 and Rolf Möller 1 

1 Department of Physics, University of Duisburg-Essen, Germany 

We present details on a homebuilt, compact scanning probe microscope (Fig. 1) which 

can be switched between tuning fork AFM and STM operation without breaking vacuum. 

The geometry of the microscope resembles a cylinder with a height of only 15 cm and a 

diameter of 4 cm. It is attached to a commercially available continuous flow cryostat 

which allows cooling to about 5-7 K. Because of the very compact design, low helium 

consumption of only 1 liter/hour is achieved. Drift rates in lateral direction are

Development of quartz force sensors for noncontact atomic force 

microscopy/spectroscopy 

Kenichirou Hori 1 , Toyoko Arai 1 and Masahiko Tomitori 2 

(a) (b) 

Amplitude[nm] 

Flexural oscillation amplitude and phase 

450 

400 

350 

300 

250 

200 

150 

100 

50 

0 

Amplitude[nm] 

Phase[degree] 

5370 5380 5390 5400 5410 5420 5430 

Frequency[Hz] 

P.I-23 

1 Graduate School of Natural science & Technology, Kanazawa University, Kanazawa, Ishikawa, Japan 

2 School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa Japan 

In order to extend the application of noncontact atomic force microscopy (nc-AFM), 

force sensors have still held the key to supplement the functions of nc-AFM, in particular, 

for force spectroscopy. For example, bias-voltage noncontact atomic force spectroscopy 

(nc-AFS) [1] developed on the basis of nc-AFM, invokes probes suitable to electric 

conductance measurements with high force sensitivity to characterize the relationship 

between binding state and electronic state. One possibility is to use quartz, one of 

piezoelectric materials with a high Q, e.g., successfully demonstrated by Giessibl [2], on 

which a metal or a Si needle is attached as a probe. Though a Si probe seems suitable to 

examine the relationship between electronic states and chemical bonding force for Si 

samples from point contact to non-contact through pseudo-contact regime, a metallic 

needle sounds as a good conductor tip. The tip material is also desired to be easily 

exchangeable. Moreover, the reduction of cantilever oscillation amplitude takes 

advantage for conductance measurement [3], which were also realized using quartz force 

sensors. Here we report the development of a quartz force sensor using lithographic 

techniques from a quartz wafer, which has electrodes suitable to simultaneous 

conductance measurement with high sensitivity of force at a small oscillation amplitude 

with feasibility of probe material change. 

We fabricated a quartz sensor with gold-plated multi-electrodes, one of which is to 

fix the potential of a probe for conductance measurement. Figure 1 shows a schematic of 

the sensor and mechanical characteristics of a flexure mode in air near its resonance 

frequency measured using a heterodyne optical interferometer. This sensor exhibits a 

longitudinal mode as well, 

analyzed them by a finite 

element method. To avoid Q 

degradation, bonding of Si tip 

onto quartz without adhesive 

agent is adopted. 

[1] T. Arai and M. Tomitori: Phys. 

Rev. B 73 (2006) 073307. 

[2] F.J. Giessibl: Appl. Phys. Lett. 76 

(2000) 1470. 

[3] T. Arai and M. Tomitori: Jpn. J. 

Appl. Phys. 39 (2000) 3753. 

100 

80 

60 

40 

20 

0 

-20 

-40 

-60 

-80 

-100 

Fig.1(a) Schematic of a fabricated sensor. (b) Resonance 

curves of the flexural mode of the sensor without a probe. 

114 

Phase[degree]

P.I-24 

High-Speed Frequency Modulation Atomic Force Microscopy using 

Wideband Digital Phase-Locked Loop Detector 

Takeshi Fukuma 1,2 and Yuji Mitani 1 

1 Frontier Science Organization, Kanazawa University, Kanazawa, Japan 

2 PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan 

Recent advancement in the instrumentation of frequency modulation atomic force 

microscopy (FM-AFM) has enabled to operate FM-AFM in liquid with true atomic 

resolution. To date, liquid-environment FM-AFM has been used for several biological 

applications, which has demonstrated its excellent force sensitivity and high spatial 

resolution. However, unlike applications in vacuum, biological applications require highspeed 

operation of FM-AFM due to the mobile nature, high complexity and large 

dimension of biological systems. In this study, we develop a high-speed FM-AFM using 

FPGA-based digital signal processing circuit in order to improve the applicability of this 

method to practical biological studies. 

Development of high-speed FM-AFM requires enhancing the bandwidth and resonance 

frequencies of all the components involved in the tip-sample distance feedback loop. In 

particular, a frequency detector has been one of the major speed limiting factors in the 

feedback loop. A conventional frequency detector using a digital phase-locked loop 

(PLL) typically utilizes multiplication-based phase comparator, which has limited its 

bandwidth to less than 10 kHz. In this study, we have developed a wideband digital PLL 

using a subtraction-based phase comparator (Fig. 1(a)). The developed PLL detector has 

a bandwidth of wider than 1 MHz (Fig. 1(b)). A high-speed FPGA circuit has been used 

for implementing the PLL as well as the cantilever excitation circuit, the distance and 

amplitude feedback control circuits. Combined with our recently developed high-speed 

scanner and wideband photo-thermal excitation system, we aim at high-speed operation 

of FM-AFM in liquid. 

Figure 1: (a) Block diagram and (b) frequency response of the developed PLL using a 

subtraction-based phase comparator (fc : cutoff frequency of a low-pass filter at the output). 

115

Recent Advances in Multi-Spectral Atomic Force Microscopy 

S. Jesse, N. Balke, P. Maksymovych, O. Ovchinnikov, A.P. Baddorf, S.V. Kalinin 

Oak Ridge National Laboratory, Oak Ridge, TN 37831 

P.I-25 

Piezoresponse force microscopy has become the primary method for the 

characterization of electromechanical activity on the nanometer scale. The recent 

introduction of the band excitation mode has allowed resonance enhancement in PFM 

through the detection of amplitude-frequency curve at each pixel. Similarly, switching 

spectroscopy PFM has allowed measurements of polarization dynamics. Both these 

techniques give rise to 3D data arrays. Combining both techniques into BE SSPFM yields 

4D data, while implementation of first order reversal curve measurements yields 5D data 

sets. In the absence of exact and reliable analytical models, data analysis of high 

dimensional data sets to elucidate relevant aspects of materials behavior and link them to 

theory represents a complex problem. 

Here we discuss an approach for the analysis of multi-dimensional, spectroscopicimaging 

data based on principal component analysis (PCA) coupled with neural network 

recognition algorithms. PCA selects and ranks relevant response components based on 

variance within the data. It is shown that for examples with small relative variations 

between spectra, the first few PCA components coincide with results obtained using 

model fitting, and achieves this at rates approximately 4 orders of magnitude faster. For 

cases with strong response variations, PCA allows an effective approach to rapidly 

process, de-noise, and compress data. The combination of PCA with correlation analysis 

is demonstrated as a means to delineate the principal components containing information 

from those dominated by noise. In ferroelectric data, PCA allows for the selection of 

minute effects related to polarization orientation changes during switching. Here, the 

PCA based approach is used to study domain wall dynamics in ferroelectric and 

multiferroic materials and polarization behavior in ferroelectric capacitors and relaxors. 

Further prospects for other multidimensional SPM methods are discussed. 

Research was supported by the U.S. Department of Energy Office of Basic 

Energy Sciences Division of Scientific User Instruments and was performed at Oak 

Ridge National Laboratory which is operated by UT-Battelle, LLC. 

Figure 1: The first 4 PCA components of band excitation magnetic force microscopy image of 

yttrium-iron garnet (data acquired in collaboration with R. Proksch, Asylum Research). PCA is 

able to decompose the data into 2 conservative, 1 background, and 1 dissipation component. 

116

P.I-26 

Deciphering Nanoscale Interactions: Artificial Neural Networks and 

Scanning Probe Microscopy 

Maxim Nikiforov, Stephen Jesse, Oleg Ovchinnikov, and Sergei V. Kalinin 

Oak Ridge National Laboratory, Oak Ridge, TN 37831 

Scanning Probe Microscopy techniques provide a wealth of information on 

nanoscale interactions. The rapid emergence of spectroscopic imaging techniques in 

which the response to local force, bias, or temperature is measured at each spatial 

location necessitates the development of data interpretation and visualization techniques 

for 3- or higher dimensional data sets. 

In this presentation, we summarize recent advances in the application of neural 

network based artificial intelligence methods to scanning probe microscopy. The 

examples will include biological identification based on the dynamics of the 

electromechanical response, direct mapping of dynamic disorder in ferroelectric relaxors, 

and reconstruction of random bond-random field Ising model parameters in ferroelectric 

capacitors. The future prospects for smart, multispectral SPMs are discussed. 

Research was supported by the U.S. Department of Energy Office of Basic 

Energy Sciences Division of Scientific User Facilities and was performed at Oak Ridge 

National Laboratory which is operated by UT-Battelle, LLC. 

Figure 1: Results of neural network identification of bacteria (M. Lysodeikticus (red), P. 

Fluorescens (green)) are overlaid on the topographic image. Training area for neural network is 

outlined by black rectangle (in collaboration with A. Vertegel and V. Reukov, Clemson 

University). 

117

P.I-27 

NC-AFM study of a cleaved InAs (110) surface using modified Si probes 

under ambient atmospheric pressure 

Yonkil Jeong 1,2 , Masato Hirade 2,3 , Ryohei Kokawa 2,3 , Hirofumi Yamada 2,4 , 

Kei Kobayashi 2,4 , Noriaki Oyabu 2,4 , Hiroshi Yamatani 2,5 , Toyoko Arai 2,5 , 

Akira Sasahara 1,2 , and Masahiko Tomitori 1,2,* 

1 School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa, Japan, 

2 JST Advanced Measurement and Analysis, 3 Shimadzu Corp., Kyoto, Japan, 

4 Kyoto University, Kyoto, Japan, 5 Kanazawa University, Ishikawa, Japan 

Characterization of crystalline defects in thin films with interfaces of lattice-mismatched 

III-V compound semiconductors such as GaAs and InP is an important issue for practical 

device application. We pursue a simple and quick method to characterize them on an 

atomic scale using NC-AFM by cleaving devices in a controlled environment without a 

UHV system. In this work, we demonstrate the possibilities of high-resolution imaging of 

a cleaved InAs (110) surface using the NC-AFM under atmospheric pressure of air or 

pure Ar, and of acquiring charge state information with specially fabricated probes, 

which are designed to emphasize electronic interaction between the tip and the sample. 

High aspect ratio (HAR) Si and Ge/Si probes were fabricated from commercial 

AFM Si probes by an FIB and a Ge deposition system. Fig. 1(a) shows the changes in ? f 

due to the reduction of capacitance between probes and a sample. A high resolution 

image with a periodic structure was successfully obtained with a fabricated probe, in Fig. 

1(c); possibly residual H2O molecules were adsorbed on a cleaved InAs (110) surface. 

(a (b 

Δf = -43Hz, A = 0.4nm 

Figure 1: (a) Bias-Δf curves between probes and a sample surface. (b) SEM images of 

FIB fabricated probes. (c) NC-AFM image of a cleaved InAs (110) with HAR-Si in Ar. 

*corresponding author e-mail: tomitori@jaist.ac.jp 

118 

(c)

Dual-Frequency-Modulation AFM Spectroscopy 

Gaurav Chawla, C. Alan Wright, and Santiago D. Solares 

Department of Mechanical Engineering, University of Maryland at College Park, USA 

P.I-28 

Force spectroscopy is an important application of atomic force microscopy (AFM), 

whereby tip-sample interaction forces are measured with probes of varying geometry and 

chemistry. Most methods rely on measuring either the instantaneous cantilever deflection 

in static mode or the frequency shift in low-amplitude frequency-modulation mode. In 

the first case the force is calculated directly from the cantilever deflection. In the second 

case the frequency shift is used to compute the tip-sample force gradient, from which the 

tip-sample force curve can be reconstructed after scanning a region for which a boundary 

condition is known. In both cases, acquiring a 3D representation of the tip-sample forces 

requires fine-grid scanning of a volume above the surface. Using computational 

simulations, we have developed a dual-frequency-modulation AFM spectroscopy method 

[1,2] in which the cantilever is simultaneously excited at the fundamental frequency and 

at a higher-order eigenfrequency (with a much smaller amplitude), such that 

topographical imaging is performed using the fundamental frequency response and force 

spectroscopy is performed using the higher-order response. Our results suggest that this 

method could enable measurement of the 3D tip-sample forces above the surface with a 

single 2D scan. The procedure was originally developed for ambient air, but has been 

extended to vacuum conditions, where we are evaluating the 3D imaging of atomic 

orbitals by integrating quantum mechanics and cantilever dynamics calculations. We are 

especially interested in the effect of tip apex geometry on the ability to image sub-atomic 

features. The method’s experimental implementation in air is in progress. 

1.85 

a b 

Dual-frequency tip response 

ν 1 band 

ν 2 band 

imaging 

spectroscopy 

Effective frequency, MHz 

1.75 

1.65 

1.55 

1.45 

0 20 40 60 80 100 

Time, ms 

Tip approach 

Tip retract 

Figure 1: (a) Illustration of the dual-frequency-modulation AFM concept, where the cantilever 

vibrates at two eigenfrequencies such that the fundamental response is used to perform imaging 

and the high-frequency response is used to perform force spectroscopy; (b) illustration of the 

instantaneous frequency of the self-excited high-frequency response for one full oscillation of the 

low-frequency response, under positive frequency shift for the fundamental frequency. Since the 

frequency shift follows the tip-sample force gradient, it is in principle possible under ideal 

conditions to extract the tip-sample force curve every low-frequency oscillation. 

[1] G. Chawla and Solares, S.D., Measurement Science and Technology 20, No. 015501 (2009). 

[2] S.D. Solares and G. Chawla, Measurement Science and Technology 19, No. 055502 (2008). 

119

Theory of Multifrequency Method in FM-AFM 

Zongmin Ma, Yoshitaka Naitoh, Yanjun Li, Masami Kageshima 

and Yasuhiro Sugawara 

Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, 

Suita, Osaka 565-0871, Japan 

P.I-29 

FM-AFM has been succeeded in measuring topography and energy dissipation 

with atomic resolution on the surface. Furthermore, force spectroscopy is 

demonstrated to identify the atomic species. The elasticity information of the surface 

is important physical information of the sample materials. Actually, it has been 

measured by using multifrequency method in AM-AFM recently, which was proposed 

by Rodriguez and Garcia and successfully demonstrated its usefulness theoretically 

and experimentally [1-2]. 

In this paper, for the first time, we 

proposed usage of the multifrequency 

f 2 

BPF PLL Δf 2 

method in FM-AFM to measure the 

AGC 

sample properties such as elasticity. 

Figure 1 shows the block diagram of 

× 

multifrequency method in FM-AFM. 

f 1 

BPF PLL 

The cantilever is excited simultaneously 

at the first and the second resonances. 

Band pass filters (BPFs) are used to 

separate the vibration signals of the 

Optical 

interferometer 

+ 

+ 

AGC 

× 

cantilever. For each signal, the cantilever 

Cantilever 

Δf 1 

is vibrated by self-oscillation at the first 

Feedback 

and the second resonances. Topography 

Tube Scanner 

Topography 

of the sample is obtained by the 

feedback signal to keep the frequency 

Figure 1. Block diagram of multifrequency 

shift (△ f1) constant. The elasticity information of the sample surface is measured by 

frequency shift (△ f2) of the second resonance, which is proportional to the 

conservative force between tip and sample. Here, we show the theory for the 

multifrequency method in FM-AFM. 

[1] Rodriguez and R. Garcia, Appl. Phys. Lett. 84, 449 (2004). 

[2] Jose R. Lozano and Ricardo Garcia. Phy Rev B 79, 014110 (2009). 

120

P.I-30 

Internal Resonances and Spatio-Temporal Instabilities in Nonlinear 

Multi-mode NC-AFM Dynamics 

Oded Gottlieb, Sharon Hornstein, Wei Wu and Arthur Shavit 

Department of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa, Israel 

The use of multi-mode excitation in atomic force microscopy has been proposed and 

validated in the past decade. Examples include the combined excitation of the first two 

bending modes where the latter has been found to be sensitive to low surface force 

variations [1], and excitation of a third bending mode in the vicinity of a torsion mode to 

map nanomechanical changes of a polymer near its glass transition [2]. While small 

amplitude excitation results in a single-valued frequency response, finite amplitude 

dynamics can yield nonlinear coexisting bi-stable solutions and complex aperiodic 

dynamics that reveal nonstationary energy transfer between multiple spatial modes. The 

accuracy of force estimation from measured data crucially depends on the quality of the 

mathematical model in use. Thus, as lumped mass models cannot describe multi-mode 

dynamics, a continuum mechanics description is required to consistently incorporate 

nonlinear atomic interaction and coupled elastic and internal damping forces that govern 

noncontact operation in ultrahigh vacuum. Thus, the objectives of this paper include 

theoretical derivation and analysis of a continuum spatio-temporal model for the 

vibrating NC-AFM cantilever that consistently incorporates both nonlinear atomic 

interaction and coupled thermo-visco-elastic damping. We derive a nonlinear initialboundary-value 

problem using the extended Hamilton's principle [3] for the coupled 

viscoelastic and temperature fields for torsion, transverse and out-of-plane bending. The 

continuum system is then reduced via a Galerkin procedure to a multi-mode dynamical 

system which is analyzed numerically. System response reveals that the dynamic jumpto-contact 

bifurcation threshold is not sensitive to the damping level but includes lengthy 

chaotic transients for low damping. Furthermore, both subharmonic and quasiperioic 

solutions are found when combination and internal resonances are excited. The latter 

reveal energy transfer between the 3rd and 2ond microbeam modes due to a strong 3:1 

internal resonance [Fig.1] and complex chaotic like spatio-temporal instabilities when 

this internal resonance is coupled with either its out-of-plane or torsion resonances. 

Figure 1: Quasiperiodic dynamics of a 3:1 internal resonance between the 3 rd and 2 nd bending 

modes in UHV: time series (left), power spectra(center), and Poincare' map (right). 

[1] T.R. Rodriguez and R. Garcia, APL, 83, 449 (2004). 

[2] O. Sahin et al. Nature Nanotechnology 2, 507 (2007). 

[3] S. Hornstein and O. Gottlieb, Nonlinear Dynamics 54, 93 (2008). 

121

P.I-31 

Frequency Noise in Frequency Modulation Atomic Force Microscopy 

Kei Kobayashi 1 , Hirofumi Yamada 2 , and Kazumi Matsushige 2 

1 Innovative Collaboration Center, Kyoto University, Kyoto, Japan. 

2 Department of Electronic Science and Engineering, Kyoto University, Kyoto, Japan. 

Atomic force microscopy (AFM) using the frequency modulation (FM) detection method 

has been widely used for atomic/molecular-scale investigations of various materials. 

Recently, it has been shown that high-resolution imaging in liquids by the FM-AFM is 

also possible by reducing the noise-equivalent displacement in the cantilever 

displacement sensor and by oscillating the cantilever at a small amplitude, even with the 

extremely reduced Q-factor due to the hydrodynamic interaction between the cantilever 

and the liquid. However, it has not been clarified how the noise reduction of the 

displacement sensor contributes to the reduction of the frequency noise in the FM-AFM 

in low-Q environments. In this presentation, the contribution of the displacement sensor 

noise to the frequency noise in the FM-AFM is analyzed in detail to show how it is 

important to reduce the noise-equivalent displacement in the displacement sensor 

especially in low-Q environments. 

As a general equation for the frequency noise density of the oscillator, we have to 

consider the contribution of the displacement sensor noise to the oscillator noise in 

addition to the frequency noise of the high-Q cantilevers, 

where N ds is the noise-equivalent displacement sensor noise density. 

Figure 1: Schematics of the evolution of the displacement noise into the frequency noise without 

and with the displacement sensor noise. The displacement noise spectrum of the cantilever around 

the resonance frequency without the displacement sensor noise (a) and the corresponding 

oscillator frequency noise (b). The total frequency noise considering the measurement noise 

(dotted area in (b)) becomes constant as shown in (c). If there is non-zero displacement sensor 

noise, it brings additional oscillator frequency noise and measurement noise as shown in (d). 

Dark gray and black areas represent two levels (small and large) of additional displacement 

sensor noise. 

[1] K. Kobayashi, H. Yamada, and K. Matsushige, Rev. Sci. Instrum. accepted for publication (2009). 

122 

,

Relation between lateral forces and dissipation in FM-AFM 

Michael Klocke, Dietrich E. Wolf 

Department of Physics, University of Duisburg-Essen, Germany. 

P.I-32 

We study the coupling of torsional and normal cantilever oscillations and their effect on 

the imaging process of a frequency-modulated atomic force microscope by means of 

molecular dynamics simulations. We show that the bending and torsional modes of the 

cantilever are coupled if the tip is near the surface and connect this coupling to the 

damping of the cantilever oscillation. The strength of the coupling is determined roughly 

by the strength of the lateral forces on the closest approach of the tip. Energy is 

transferred from the normal to the torsional excitation which can be detected as damping 

of the cantilever oscillation. Energy is actually dissipated by the usually uncontrolled 

mechanical damping of the torsional excitation. For high Q factors, the transferred energy 

is not completely dissipated during one cycle. The question, what happens to the 

remaining energy of the lateral degree of freedom in the long run, is addressed by 

studying a simplified two-dimensional point-mass model. We show that in succeeding 

cycles, energy is transferred back into the normal degree of freedom. The observation of 

the energy swapping process (amplitude and frequency) can therefore give additional 

information of the surface structure, especially on lateral forces. 

123

P.I-33 

Experimental Study of Dissipation Mechanisms in AFM Cantilevers 

Fredy Zypman 

Department of Physics, Yeshiva University, New York, USA. 

The presence of energy dissipation in an oscillating AFM cantilever is a fact that must be 

included in any force reconstruction algorithm. Although commonly low quality factor 

(Q) cantilevers get on the way of high accuracy non-contact measurements, some times 

they can be used purposely. A case in point is the study of the measurement of fluids 

viscosity by monitoring changes in Q [1]. In this work we study theoretically the 

mechanisms of energy dissipation in AFM, and validate the corresponding models 

experimentally. This understanding of the origins of energy dissipation is not only 

interesting for its own sake, but it is also relevant with an eye on practical applications. 

We have done extensive work on cantilevers of various shapes but, to fix ideas we 

consider a rectangular cantilever in this abstract. In that case, the beam model is 

commonly used to obtain the corresponding frequency spectrum via the steady state 

4 

2 

EI ∂ u( 

x, 

t) 

∂ u( 

x, 

t) 

solution of + = 0 , where u( x, 

t) 

is the deflection of the cantilever 

4 

2 

Aρ 

∂x 

∂t 

at location x and time t , E is the Young's modulus, I the cross sectional moment of 

inertia, A the cross sectional area, and ρ the mass density. In the beam model, a 

∂u dissipation term proportional to is usually introduced. The proportionality factor is a 

∂t 

difficult problem in itself that involves the interaction of the cantilever with the 

surrounding fluid [2]. The complete equation describes quite well the central frequency 

and width of multiple peaks. However, a detailed analysis shows that the peak shape is 

not in full agreement with experiment if fine details are included. We will show that this 

is improved by introducing explicit dissipation terms based on basic physical principles 

that represent cantilever-fluid interaction and internal viscoelasticity. The model is 

solved and compared with experimental data obtained on a Veeco AFM. We will also 

argue that this improvement is necessary to produce reconstruction algorithms consistent 

with the resolutions necessary today to measure objects at the subnanometer scale, like 

charges in biological molecules. 

[1] A. Schilowitz, D. Yablon, E. Lansey, and F. Zypman, Measurement 41, 1169 (2008). 

[2] J.E. Sader, J. Appl. Phys. 84, 64 (1998) 

124

M. Teresa Cuberes 

Ultrasonic Nanolithography on Hard Substrates 

Laboratory of Nanotechnology, University of Castilla-La Mancha, Almadén, Spain. 

P.I-34 

Ultrasonic- AFM techniques provide a means to monitor ultrasonic vibration at the 

nanoscale and open up novel opportunities to improve nanofabrication technologies [1]. 

Ultrasonic Force Microscopy (UFM) relies on the mechanical-diode cantilever response 

when ultrasonic vibration is excited at the tip-sample contact [2]. Strictly, UFM is a 

dynamic AFM (Atomic Force Microscopy) implementation in which the tip-sample 

contact is periodically broken at ultrasonic frequencies. In the presence of ultrasonic 

vibration, the tip of a soft cantilever can dynamically indent hard samples due to its 

inertia. Fig. 1 (a) demonstrates scratching of a silicon sample in the presence of ultrasonic 

vibration, using a cantilever with nominal stiffness of 0.11 Nm -1 and a SiN tip. In the 

absence of ultrasound, it was not possible to scratch the Si surface using such a soft 

cantilever. Interestingly, no debris is found in the proximity of lithographed areas. 

Fig. 1 (b) displays ultrasonic curves -UFM response for increasing ultrasonic 

excitation amplitude- recorded during UFM imaging (curve (a)) and during scratching of 

silicon (curves c-d). UFM imaging is carried out without substrate modification by using 

a lower tip-sample load. When increasing the load, the silicon substrate is scratched 

provided a sufficiently high ultrasonic amplitude is excited. By monitoring the ultrasonicinduced 

cantilever responses during manipulation, information about the substrate 

modification can be obtained. As the substrate is being scratched, the UFM responses 

change. Apparently, for a fixed load, a critical ultrasonic amplitude is needed to induce 

modification (see Fig 1 (b)). In the poster, the advantages of ultrasonic nanolithography, 

and the shape of UFM curves recorded during manipulation will be discussed in detail. 

a) b) 

Figure 1. AFM scratching of Si(111) in the presence of normal surface ultrasonic vibration of ~ 

5 MHz using a pyramidal SiN cantilever tip with nominal stiffness 0.11 Nm -1 (a) Nanotrenches 

formed in 50, 70 and 100 cycles respectively, at a load of ~ 40 nN and maximum ultrasonic 

amplitude Am = 500 mV (b) UFM response for a triangular modulation of the ultrasonic 

excitation (see lowest curve). Load: (i) ~ 26 nN. (ii-iv) ~ 40 nN. Am=500 mV. 

[1] M. T. Cuberes, J. of Phys.: Conf. Ser. 61 (2007) 219. 

[2] M. T. Cuberes in “Applied Scanning Probe Methods”, B. Bhushan and H. Fuchs (ed.), Springer 2009. 

125

P.I-35 

Silicon nanowire transistors with a channel width of 4 nm fabricated by 

atomic force microscope nanolithography 

Javier Martinez, Ramses V. Martinez, and Ricardo Garcia 

Instituto de Microelectronica deMadrid - CSIC, Isaac Newton 8, 28760 Tres Cantos, Madrid, Spain 

The emergence of an ultrasensitive sensor technology based on silicon nanowires 

requires both the fabrication of nanoscale diameter wires and the integration with 

microelectronic processes [1]. Here we demonstrate an atomic force microscopy 

lithography that enables the reproducible fabrication of complex single-crystalline silicon 

nanowire field-effect transistors with a high electrical performance. The nanowires have 

been carved from a silicon-on-insulator wafer by a combination of local oxidation 

processes [2] with a force microscope and etching steps. We have fabricated and 

measured the electrical properties of a silicon nanowire transistor with a channel width of 

4 nm. The flexibility of the nanofabrication process is illustrated by showing the 

electrical performance of two nanowire circuits with different geometries [3]. The 

fabrication method is compatible with standard Si CMOS processing technologies and, 

therefore, can be used to develop a wide range of architectures and new microelectronic 

devices. 

(a) (b) 

1 µm 

Figure 1: (a) AFM image of a silicon nanowire transistor that combines linear and circular 

regions and (b) output characteristics of the silicon nanowire transistor. 

[1] Y. Ciu, C. M. Lieber. Science 291, 851 (2001). 

[2] R. Garcia, R. V. Martinez, J. Martinez. Chemical Society Reviews 35, 29. (2006). 

[3] J. Martinez, R. V. Martinez, R. Garcia. Nano Letters 8, 3636, (2008). 

Contact author: Ricardo García, rgarcia@imm.cnm.csic.es 

126

Contacting self-ordered molecular wires by 

nanostencil lithography 

L. Gross, R.R. Schlittler, and G. Meyer 

IBM Research, Zurich Research Laboratory, 8803 Rüschlikon, Switzerland 

Th. Glatzel, S. Kawai, S. Koch, and E. Meyer 

Department of Physics, University of Basel, 4056 Basel, Switzerland. 

P.I-36 

We grew self-ordered cyanoporphyrin molecular wires [1] on thin epitaxial NaCl(100) 

layers on top of GaAs substrates under UHV conditions. This molecular assemblies form 

one- and two-dimensional wires with a length of several 10nm depending on the substrate 

conditions. Using a shadow masking technique [2], a nanostencil combined with a room 

temperature nc-AFM in UHV, we additionally evaporate Au and Cr electrodes with a 

thickness of around 3nm in situ. The resulting combined molecular and metal structures 

are investigated by means of nc-AFM and KPFM (Kelvin probe force microscopy). 

While nc-AFM enabled us to control the tip sample distance on the very complex and 

partly insulating surface, KPFM has been used to determine and compensate changes of 

the local contact potential difference (LCPD). 

Figure 1: (a) nc-AFM image (size 1.7um x 1.7um, LCPD compensated) of NaCl/GaAs covered 

with cyanoporphyrin molecular wires and clusters. A Cr electrode was evaporated through a 

stencil mask in order to contact molecular wires. b) Simultaneously measured LCPD of the 

structure. 

[1] Th. Glatzel, L. Zimmerli, S. Koch, S. Kawai, and E. Meyer, Appl. Phys. Lett. 94, 063303 (2009). 

[2] P. Zahl, M. Bammerlin, G. Meyer, and R. R. Schlittler, Rev. Sci. Instrum. 76, 023707 (2005). 

127

Poster 

Session II 

Wednesday, 12 August 

128

Molecular Structures of Organic Single Crystals Investigated by 

Frequency Modulation Atomic Force Microscopes 

Taketoshi Minato 1 , Hiroto Aoki 2 , Thorsten Wagner 3 2, 4 

, and Kingo Itaya 

129 

P.II-01 

1 

Institute for International Advanced Interdisciplinary Research (IIAIR), Tohoku Univ., 6-6-07 Aoba, 

Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan 

2 

Department of Applied Chemistry, Tohoku Univ., 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980- 

8579, Japan 

3 

University at Duisburg-Essen, Fachbereich Physics, Lotharstr. 1-21, 47057 Duisburg, Germany 

4 

World Premier International Research Center (WPI), Tohoku Univ., 6-6-07 Aoba, Aramaki, Aoba-ku, 

Sen-dai, Miyagi 980-8579, Japan 

Recently, single crystals of organic semiconductors such as rubrene [1], 

pentacene [2] and PTCDA [3] are attracting great interest as materials to be used for 

organic field effect transistors (OFETs). It is important to characterize geometric and 

electronic structures of organic layers in molecular levels in order to achieve higher 

carrier mobility. Here, we describe applications of Frequency Modulation Atomic Force 

Microscopy (FM-AFM) for single crystal to investigate the molecular structure [4, 5]. 

First, we measured FM-AFM images on 

prepared pentance single crystals in UHV. The 

obtained molecular resolved FM-AFM images 

showed very wide terrace (2 – 3 um) and high 

crystallity of prepared single crystal without 

molecular defects [2]. Also, we have recently 

achieved molecular resolution on a rubrene single 

crystal in UHV [5]. Fig. 1 shows a FM-AFM 

image in 5.0 nm × 5.0 nm. This also showed high 

crystallity of prepared single crystal without 

molecular defects as same as pentacene single 

crystals. Such results strongly suggest that the 

prepared organic single crytals are applicable to 

OFETs. 

Figure 1 A FM-AFM image 

(5.0 nm × 5.0 nm) of rubrene 

single crystal. Tsample = 298 K. 

References 

[1] R. W. I. de Boer, M. E. Gershenson, A. F. 

Morpurgo, V. Podzorov, Phys. Status Solidi A, 201, 1302 (2004). 

[2] V. Y. Butko, X. Chi, D. V. Lang, A. P. Ramirez, Appl. Phys. Lett. 83, 4773 (2003). 

[3] T. Wagner, A. Bannani, C. Bobisch, H. Karacuban, M. Stohr, M. Gabriel, R. Moller, 

Org. Elect., 5, 35 (2004). 

[4] K. Sato, T. Sawaguchi, M. Sakata, and K. Itaya, Langmuir, 23, 12788 (2007). 

[5] T. Minato, H. Aoki, T. Wagner, H. Fukidome and K. Itaya, J. Am. Chem. Soc., 

submitted (2009).

Imaging of aromatic molecules by tuning-fork based LT-NC-AFM 

P.II-02 

Bartosz Such 1 , Thilo Glatzel 1 , Shigeki Kawai 1 , Sacha Koch 1 , Alexis Baratoff 1 , Ernst 

Meyer 1 , Catelijne H. M. Amijs 2 , Paula de Mendoza 2 , and Antonio M. Echavarren 2 

1 Department of Physics, University of Basel, Kilngelbergstrasse 82, 4056 Basel, Switzerland 

2 Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain. 

Utilizing tuning forks [1,2] as sensors for NC-AFM allowed for extending 

capability of the technique to cryogenic temperatures. 

In the presentation, high resolution imaging of large aromatic molecules at 5K will 

be presented. Functionalized truxeses (10,15-dihydro-5H-diindeno[1,2-a;1',2'c]fluorine) 

with three 4-cyanobenzyl groups added in positions 5, 10, and 15 in a syn relative 

configuration have been evaporated onto a clean Cu(111) surface. The molecules adopt 

planar configuration and form a triangular network (see fig. 1). However, the 

cyanobenzyl groups are flexible and can adopt various configurations for neighbouring 

molecules. Supposedly the cyanobenzyl groups standing in the upright position appear in 

frequency shift images as dark spots (areas of larger interaction) due to enhanced 

electrostatic interaction with the tip, proving NC-AFM capability of imaging internal 

structures of aromatic molecules. 

Figure 1: 7.8x7.8 nm constant height image of truxene layer on Cu(111) surface. a) current (tip 

bias = -1.8 V, colour scale form 173 pA to 503 pA); b) frequency shift, Ap-p = 260 pm f0 = 26417, 

Q = 47000, colour scale from -56.5 Hz to -34.8 Hz. 

[1] F.J. Giessibl, Appl. Phys. Lett. 76, 1470 (2000). 

[2] M. Ternes et al. Science 319, 5866 (2008). 

130

One and Two Dimensional Structure of Water on Cu(110) and 

O/Cu(110)-(2x1) Surface 

Byoung Y. Choi 1 , Yu Shi 1,2 , Thomas Duden 3 , and Miquel Salmeron 1,2 

1 Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, USA 

2 Department of Materials Science and Engineering, University of California, Berkeley, USA 

3 National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, USA. 

P.II-03 

The interaction of water on metal surfaces like Ru, Pt, or Pd has been studied for a long 

time to understand its role in catalysis, electrochemistry and environmental science. 

Especially, the structure of water on atomically clean surfaces has been an important 

subject because of its complexity. Water molecules can easily diffuse and aggregate on 

the surface at over ~40K to form a two dimensional (2D) hexagonal structure on closepacked 

metallic surfaces [1] . 

For water on Cu, it has been reported that it forms 1D-like chains at low coverage on 

the (110) surface while it forms 2D hexagonal networks at higher coverage. It has been 

proposed that this 1D wire is built from hydrogen bonded hexagons as building blocks 

[2]. The 1D chain structure was recently suggested to be a combination of pentagons 

based on experiment and theory [3]. An important question is how the pentagon based 

chains evolve into hexagon based 2D networks. To determine this, more careful 

investigation at the atomic scale is required. 

Atomic force microscopy (AFM) in non-contact (NC) mode can be used to study the 

molecules on metals and insulators with atomic resolution. We built a tuning fork base 

NC-AFM which works in both 4K and 77K with a FET type current amplifier on the low 

temperature side to reduce a noise coupling through the signal lines. Our instrument can 

work in either the NC-AFM or STM mode, which provides complementary information 

and is useful for reference and calibration. 

With this instrument we investigated the evolution of water from 1D chain to 2D 

network on clean and oxygen precovered Cu(110) surfaces at low temperature, which 

reveals the growth mechanism of water at various coverages and growth temperatures. 

By dosing water on partially covered O/Cu(110)-(2x1) surface, we were able to show that 

the oxygen atoms at the edges of CuO rows play an important role in forming well 

ordered 2D hexagonal networks even at low coverage. Finally we suggest that water 

hexamer can be a base structure of both 1D and 2D islands when it grows adjacent to 

CuO row. 

[1] Angelos Michaelides and Karina Morgenstern, Nature Mater. 6, 597 (2007). 

[2] T. Yamada, S. Tamamori, H. Okuyama, and T. Aruga, Phys. Rev. Lett. 96, 036105 (2006) 

[3] Javier Carrasco, Angelos Michaelides, Matthew Forster, Sam Haq, Rasmita Raval and Andrew 

Hodgson, Nature Mater. doi:10.1038/nmat2403 (2009). 

131

P.II-04 

Dynamical simulations of truxene molecules adsorbed on the KBr (001) 

surface 

Thomas Trevethan 1,2 and Alexander Shluger 2 

1 Department of Physics and Astronomy, University College London, London, UK 

2 WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan. 

We present the results of calculations performed to model the dynamical behavior of 

truxene derivative molecules adsorbed on the KBr (001) surface, which have been 

imaged at room temperature with the NC-AFM with both molecular and atomic 

resolution. An atomistic potential model of the system was built from extensive quantum 

chemical calculations and used to investigate the room temperature mobility of the 

molecules on different surface sites at room temperature using molecular dynamics 

simulations. We find a hierarchy of rates of diffusion on different surface structures: the 

molecule is highly mobile on the perfect terrace and is bound to, but mobile along, the 

perfect monolayer step edge. The molecule is more strongly bound to double layer kinks, 

as observed by their immobilization at these sites in the experimental images; however 

the binding energies of the molecule on the two different polarity kinks are very similar. 

We show using dynamical simulations how one polarity kink results in a much higher 

residence time than the other, suggesting the identity of the kinks in the experimental 

images and hence of the identity of the sublattice. 

132

Temperature-dependent growth of C60 on CaF2(111) 

Felix Loske, Philipp Maaß, Jens Schütte, and Angelika Kühnle 

Department of Physics, Universität Osnarück, Barbarastraße 7, 49076 Osnabrück ,Germany 

E-Mail: floske@uos.de 

P.II-05 

Non-contact atomic force microscopy was employed to study the system of C60 

molecules on the CaF2(111) surface in-situ at various temperatures. The molecules were 

observed to be very mobile on the surface at room temperature (RT), as they nucleate at 

step edges and form large islands on the terraces. Both, regular triangular islands as well 

as branched structures were observed to coexist (Fig. 1b and 1c). The branched structures 

were seen to change shape during measuring. S. Burke et al. have previously reported 

about such branched structures on alkali halides [1]. 

The compact islands of C60 on CaF2 are at least two layer high, and at higher coverages 

C60 molecules grow in a dendritic manner onto the these compact C60 islands (Fig. 1d). In 

contrast, at low temperatures (LT) hexagonal islands are predominant, which are initially 

only one layer high. Here, already the second layer is growing in a dendritic manner (Fig. 

1a). 

These temperature-dependent measurements allow to gain insight into the molecular 

dynamics of this system and to specify the diffusion barrier. Microscopic growth models 

are shortly addressed to explain the measured island morphologies. 

Figure 1: Topographic NC-AFM images. (a) C60 island with dendritic second layer at LT. (b) 

and (c) represent the coexistence of compact triangular and branched islands at RT, with dendritic 

growth starting at the second layer (d). 

[1] S.A. Burke, J.M. Mativetsky, S. Fostner, P. Grütter, Phys. Rev. B 76, 035419 (2007) 

133

134 

P.II-06 

Creating 1D nanostructures: Heptahelicene-carboxylic acid on Calcite 

Philipp Rahe 1 , Markus Nimmrich 1 , Jens Schütte 1 , Irena G. Stara 2 and Angelika Kühnle 1 


2 Institute of Organic Chemistry and Biochemistry, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic 

Creating nanostructures on a molecular level has received an exceptional level by 

depositing molecules on metal surfaces. Structures with two-, one- or quasi zerodimensionality 

have successfully been created [1,2]. When deposited onto insulating 

substrates, one-dimensional nanostructures may act as wires in future molecular 

electronic devices. Recently, first results of such structures on insulating surfaces have 

been presented, binding molecules to step edges [3] or forming wires consisting of 

several molecules in width [4]. 

Here, we present a study of heptahelicene-carboxylic acid adsorbed on the calcite 

(10-14) surface. The molecules are sublimated in-situ from a glass crucible. Both, 

molecule deposition and NC-AFM imaging are performed in ultra-high vacuum. As 

presented in Fig 1, we observe single and double rows, which align along the [010] 

substrate direction. These structures are not bound to step edges. Rows are formed at 

room temperature and stabilize presumably by hydrogen bonds between the carboxylic 

end groups forming pairs as well as by π-π stacking along the molecular row. 

[1] J. Barth et al. Annu Rev Phys Chem 58, 375 (2007). 

[2] A. Kühnle. Curr Op Coll Interf Sci 14, 157 (2009). 

[3] S. Maier et al. Small 4, 1115 (2007). 

[4] M. Fendrich et al. Appl Phys Lett 91, 023101 (2007). 

Figure 1: Frequency shift image taken at 

room temperature. Rows along the [010] 

substrate direction are presented: Single 

rows (solid circle) and double rows (dashed 

circle). Adjacent to the double rows, further 

single rows may attach as marked by a white 

triangle.

P.II-07 

Atomic Force Microscopy Study of Cross-Linked C32H66 Monolayer by 

Low-Energy (10eV) Hyperthermal Bombardment 

Y. Liu 1 , H.Y. Nie 2 , D.Q. Yang 2 , M.W. Lau 2 and J. Yang 1 

1 Department of Mechanical and Materials Engineering, University of Western Ontario, Ontario, Canada 

2 Surface Science Western, University of Western Ontario, Ontario, Canada 

Email: yliu452@uwo.ca 

Low-energy (10eV) hydrogen projectiles generated in a special production prototype 

reactor are being developed in our study to only break the C-H bonds with other bonds 

intact on C32H66 monolayer, as spin cast on a silicon wafer. The generation of free carbon 

radicals leads to neighboring cross-link and form covalent C-C bonds [1]. The newly 

formed surface is characterized by a combination of XPS, optical contact angle 

measurement and dynamic atomic force microscopy (AFM). Especially, AFM study is 

focused on to correlate with the results from other two techniques. Roughness AFM 

results demonstrate a temporal behavior of C32H66 monolayer surface modification, 

corresponding to bombardment time which is proportional to the influence during 

bombardment process. The transiting roughness measurements can also interpret the 

directional properties of the formed covalent C-C bonds. 

The controllability of the surface modification is additionally demonstrated by the 

evolution of hydrophibilicity of the monolayer as measured by the aid of AFM and 

contact angle measurements. Phase image by tapping mode AFM provides necessary 

contrast on other mechanical properties and/or adhesion energy to evaluate the untreated 

and treated areas on an incompletely bombarded monolayer surface [2]. The results are 

further associated with the measurements from force modulation and torsion resonance 

modes to provide a critical bombardment time essential to carry on a complete 

bombardment and guarantee the surface homogeneity. All of the results confirm crosslinking 

C-C bonds as formed after bombardment and explain the enhanced surface and 

mechanical properties through the developed hyperthermal bombardment. 

[1] Z. Zheng, X.D. Xu, X.L. Fan, W.M. Lau, and R.W.M. Kwok, J. Am. Chem. Soc. 126, 12336 (2004) 

[2] J. 1. Tamayo, J. and R. Garcia, Appl. Phys. Lett., 71, 2394 (1997). 

135

P.II-08 

Towards a molecule-based Ferroelectric-OFET: surface modification of 

PZT mediated through functionalized thiophene derivates 

Peter Milde 1 , Kinga Haubner 2 , Evelyn Jaehne 2 , Denny Köhler 1 , Ulrich Zerweck 1 , and 

Lukas M. Eng 1 

1 Department of Applied Photophysics, TU Dresden, Dresden, Germany 

2 Institute of Macromolecular Chemistry and Textile Chemistry, TU Dresden, Dresden, Germany 

Organic field effect transistors (OFETs) and their application have become a field of 

intense research due to significant advances in molecular design and integration [1]. For 

an OFET-design whith a gate “electrode” that is made out of a ferroelectric (FE), we may 

expect even more functionality due to the strong and remanent electric field arising from 

bound surface charges at the FE/molecule interface [2]. In order to achieve excellent 

electric transport properties, a high degree of intermolecular ordering is inevitable [3]. 

In our approach, lead zirconate titanate (PZT) is used as material of choice for designing 

an ultrathin ferroelectric gate electrode in a Ferroelectric-OFET. The focus of the present 

work is on the film formation process of the molecularly thin organic conduction layer 

based on α,ω-dicyano-β,β*-dibutylquaterthiophene (DCNDBQT). Film formation is 

effectively promoted through specifically designed, bifunctional self-assembling 

molecules (CNBTPA: 5-cyano-2-(butyl-4-phosphonic acid)-3butylthiophene) which act 

as template layer (see Fig. 1). We report on nc-AFM and KPFM [4] investigation of the 

template layer's structural and electronical properties. 

D 

Org. 

DCNDBQT 

Ferroelectric Gate 

Conductive Gate 

Figure 1: Schematic of the proposed molecular OFET design. The CNBTPA template layer 

promotes both bonding of the organic semiconductor onto the PZT substrate and the self 

assembling of the DCNDBQT layer. 

[1] see for instance: phys. stat. solidi A 205(3) (2008) 

[2] S. Gemming, R, Luschtinetz, W. Alsheimer, G. Seifert, Ch. Loppacher, and L.M. Eng, Journal of 

Computer-Aided Materials Design 14(S1), 211 (2007) 

[3] K. Haubner, E. Jähne, H.-J.P. Adler, D. Köhler, Ch. Loppacher, L.M. Eng, J. Grenzer, A. 

Herasimovich, and S. Scheinert, phys. stat. solidi A 205(3), 430 (2008) 

[4] U. Zerweck, Ch. Loppacher, T. Otto, S. Grafström, and L.M. Eng, Phys. Rev. B 71, 125424 (2005) 

S 

136

Imaging and Detection of Single Molecule Recognition Events on 

Organic Semiconductor Surfaces 

P.II-09 

N. S. Losilla 1 ,J. Preiner 2 , , A. Ebner 2 , P. Annibale 3 , F. Biscarini 3 , R. Garcia 1 and P. 

Hinterdorfer 2 

1 Instituto de Microelectrónica de Madrid, CSIC, Tres Cantos, Spain 

2 Johannes Kepler University of Linz, Austria 

3 CNR-Istituto per lo Studio dei Materiali Nanostrutturati (ISMN),Italy 

The combination of organic thin film transistors and biological molecules could open 

new approaches for the detection and measurement of properties of biological entities. To 

generate specific addressable binding sites on such substrates, it is necessary to determine 

how single biological molecules, capable of serving as such binding sites behave upon 

attachment to semiconductor surfaces. Here, we use a combination of high-resolution 

atomic force microscopy topographical imaging and single molecule force spectroscopy 

(TREC), to study the functionality of antibiotin antibodies upon adsorption on pentacene 

islands, using biotin-functionalized, magnetically coated AFM tips. The antibodies could 

be stably adsorbed on the pentacene, preserving their functionality of recognizing biotin 

over the whole observation time of more than one hour. We have resolved individual 

antigen binding sites on single antibodies for the first time. This highlights the resolution 

capacity of the technique. 

Figure 1: (a) Scheme of the simultaneous topography and recognition AFM imaging of antibiotin 

antibodies adsorbed on pentacene islands. A magnetically driven cantilever oscillates across the 

surface. The oscillation signal is split into two parts of which the lower part is used to generate 

the topography (topography signal, red) and the upper part is used for the recognition image 

(recognition signal, green).(b) Antibody molecule on pentacene with its expected size and shape. 

[1] J. Preiner et al. Nano Lett., , 9, 571( 2009). 

a) b) 

137 

10 nm 

100 nm

P.II-10 

Transverse conductance image of DNA probed by current-feedback 

noncontact AFM 

T. Matsumoto 1, Y. Maeda 2, and T Kawai 1 

1 Institute of Scientific and Industrial Research (ISIR), Osaka Universit,Osaka, Japan 

2 National Institute of Advanced Industrial Science and Technology (AIST), Osaka Japan 

Scanning probe microscopy (SPM), which provides means to access to individual 

molecule, has a special significance for investigations of molecular-scale electronics. In 

particular, scanning tunneling microscopy (STM) has been used to evaluate molecular 

conductivity. However, STM measurement is effective only for height-foreknown system 

such as the molecules embedded in self-assembled monolayer. For the molecules having 

conformational variations, STM measurement is unable to separate the information of 

transverse conduction through the molecules from the unknown height variation. 

We demonstrated that simultaneous measurement of tunnel current and frequency 

shift realized to separate electrical properties from topographic variations. Figure 1(a) 

shows simultaneously obtained STM topography (constant-current mode) and frequency 

shift image of DNA on Cu (111) surface. These images are totally similar to each other 

but the contrast distribution of these images shows differences. For the quantitative study 

of these variances, the correlation between STM height and frequency shift is analyzed by 

plotting each pixel as shown in Figure 2(a). The negative frequency shift overall increase 

as increasing STM height. This indicates that the tip close to the molecule at the high 

region of STM topography. Assuming the transverse electron tunneling through DNA 

molecules, frequency shift and STM height show linear relationship as a function of 

transconductance G0 at molecule/surface interface and attenuation decay constant β. The 

line represented in Figure 2(a) means the data sets of STM height and frequency shift 

satisfying a parameter set of G0=0.27 and β= 0.26 . The pixel data picked from the plots 

around this line is used for reconstructing an image which shows a slice indicating the 

conduction with G0=0.27 and β= 0.26. As shown in Figure 2(b), the conductance image 

differ from either STM topography and frequency shift image in that it reflects the 

conductance variations affected by molecular conformation and/or molecules/substrate 

interface. 

STM topography Frequency shift image 

Fig. 1. Simultaneously obtained STM 

topography and frequency shift image 

of DNA on Cu (111). 

(a) Correlation analysis (b) Conductance image 

Frequency shift (Hz) 

4 

2 

0 

-2 

-4 

-6 

(G 0 ,β ) = (0.26, 0.27) 

-8 

-6 -4 -2 0 2 4 6 8 

STM height (nm) 

Fig. 2. (a) Correlation analysis between STM height 

and frequency. (b) Conductance image reconstructed 

from the data around the line of G0=0.27, β= 0.26. 

138

P.II-11 

Imaging Schwann Cell NGF Receptors using Atomic Force Microscopy 

Ryan Williamson and Cheryl Miller 

Department of Biomedical Engineering, Saint Louis University, St Louis, MO, USA. 

Nerve growth factor (NGF) is a necessary neurotrophic agent that promotes neural 

survival and proliferation. Production of NGF by Schwann cells is essential for 

successful nerve regeneration. During neural axotomy and the resulting Wallerian 

degeneration, Schwann cells increase proliferation while axons and their myelin sheaths 

are degraded. The resulting formation, the band of Bungner, is crucial for guidance of 

axon sprouts which form during regeneration. Schwann cells in the distal axon will 

express the high affinity NGF receptor tyrosine kinase A (TrkA) selectively in the bands 

of Bungner as well as the low affinity receptor p75. Using force measurements taken 

with a modified atomic force microscopy (AFM) tip to detect binding events, NGF 

receptor locations were identified. Using AFM with Schwann cells, we investigated the 

expression and conformation of NGF receptors. Receptor location and change during 

axon-Schwann cell contact could explain Schwann cell role during regeneration and 

possible clinical solutions. 

139

Comparative Studies on Water Structures on Hydrophilic and 

Hydrophobic Surfaces by FM-AFM 

Kazuhiro Suzuki 1 , Noriaki Oyabu 1,2 , Kei Kobayashi 3 , Kazumi Matsushige 1 , 

and Hirofumi Yamada 1 . 


2 Japan Science and Technology Agency /Adv. Meas. and Analysis, Japan 

3 Innovative Collaboration Center, Kyoto University, Kyoto, Japan 

P.II-12 

Water structures play essential roles in various biochemical functions such as selfassembly 

of proteins and molecular recognition between ligands and receptors. Recently 

we succeeded in three-dimensional molecular-scale visualization of water structures on 

hydrophilic surfaces including a mica surface and a purple membranes using frequency 

modulation atomic force microscopy (FM-AFM) [1]. 

In this study water structures on a hydrophobic highly oriented pyrolytic graphite 

(HOPG) surface were investigated using FM-AFM. The results were compared with 

those obtained on the hydrophilic mica surfaces. Figure 1 shows frequency shift-distance 

curves measured on the HOPG surface (a) and on the mica surface (b). The oscillatory 

behavior, originating from the water structure on each surface, can be observed in each 

curve. However, there is a clear difference in the number of the water layers between the 

two curves, which reflects the difference in the hydrophilicities of the two surfaces. In 

addition, a possible effect of the hydration structure on the AFM tip surface was 

investigated by using a chemically modified tip with a self-assembled monolayer film. 

Figure 1: Frequency shift-distance curves measured on a hydrophobic HOPG surface (a) and on 

a hydrophilic mica surface (b). Arrows indicate the peaks produced by the water layers. 

[1] K. Kimura et al, The 11 th International Conference on Non-Contact Atomic Force Microscopy, 

Madrid 2008, Oral Presentation Th-1200. 

140

Molecular Resolution Investigation of Lysozyme Crystal 

in Liquid by Frequency-Modulation AFM 

P.II-13 

K. Nagashima 1,2 , M. Abe 1,2 , S. Morita 1,2 , N. Oyabu 2,3 , K. Kobayashi 2,3,4 , H. Yamada 2,3 , 

R. Murai 1 , H. Adachi 1,5 , K. Takano 1,5 , H. Matsumura 1,5 , S. Murakami 5,6 , T. Inoue 1,5 , Y. 

Mori 1,5 , M. Ohta 2,7 , R. Kokawa 2,7 

1Grad. School of Eng., Osaka Univ.; 2 SENTAN, JST; 3 Electronic Sci. & Eng., Kyoto Univ.; 4 Innovative 

Collaboration Center, Kyoto Univ.; 5 SOSHO Inc.; 6 Grad. School of Biosci. and Biotech., Tokyo Insti. of 

Tech.; 7 Shimadzu Corporation 

Recently, Frequency-Modulation AFM (FM-AFM) in liquids has opened a new 

way to direct visualization with atomic or molecular resolution [1,2]. We have developed 

a high-resolution FM-AFM working in liquids based on a commercially available AFM 

(Shimadzu: SPM-9600), which obtained atomic or molecular resolution in liquid [3]. 

We have tried to observe protein crystals in liquid. To make high quality protein 

crystals is very important for determining its molecular structure by X-ray diffraction 

analysis. We observed (110) face of tetragonal lysozyme crystal in saturated solution. A 

surface unit cell (11.2 x 3.8 nm) consists of 4 molecules with different orientations from 

one another (Fig. 1a). We observed it for the first time at molecular resolution (Fig. 1b), 

which was not achieved in contact mode AFM [4]. In addition, we also succeeded to 

observe changes of the terrace with admolecule and the point defect when the terrace was 

covered with a single unit layer (height = 5.6 nm) in supersaturated solution. Such 

observations are considered to be fruitful technique for investigating growth mechanism 

at molecular level. 

a) b) 

c c 

5 nm 

Figure 1: (a) The molecular-packing arrangement of the tetragonal lysozyme (110) face. The 

surface unit cell shows black rectangle. (b) FM-AFM image of tetragonal lysozyme (110) face. 

[1] T. Fukuma, K. Kobayashi, K. Matsushige, H. Yamada, Appl. Phys. Lett. 86 (2005) 193108. 

[2] T. Fukuma, K. Kobayashi, K. Matsushige, H. Yamada, Appl. Phys. Lett. 87 (2005) 34101. 

[3] S. Rode, N. Oyabu, K. Kobayashi, H. Yamada, A. Kuhnle, Langmuir 25 (2009) 2850. 

[4] H. Li, M. A. Perozzo, J. H. Konnert, A. Nadarajaha, M. L. Pusey, Acta Cryst. D55 (1999) 1023. 

141

Noncontact Atomic Force Microscope Observation 

of TiO2(110) Surface in Pure Water 

Akira Sasahara 1 , Yonkil Jeong 1 , and Masahiko Tomitori 1 

1 School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa, Japan 

P.II-14 

Titanum dioxide (TiO2) has a wide range of industrial applications such as pigments, 

optical devices, catalyst supports, photocatalysts, and photoelectrodes. A rutile 

TiO2(110) surface, which exhibits a simple truncation of the bulk structure (Fig. 1(a)) by 

simple cleaning procedures, has been most frequently employed in ultra high vacuum 

(UHV) studies to understand the origin of its properties. In many of the applications, 

TiO2 demonstrates the excellent properties in the presence of aqueous media. Nanoscale 

investigation of a well-defined rutile TiO2(110) surface in a liquid possibly provides 

further insight into the surface chemical properties of TiO2. We attempted noncontact 

atomic force microscope (NC-AFM) observation of TiO2(110) surface in pure water. 

The experiments were performed by using an intermittent contact mode atomic force 

microscope (5500 AFM/SPM, Agilent Technologies). The microscope was operated as 

an NC-AFM by using a phase locked loop detector (easy PLL plus, Nanosurf AG). The 

microscope was placed in a glass chamber, and imaging was performed under a flow of 

Ar. The TiO2(110) surface was cleaned by cycles of Ar + sputtering and annealing in 

UHV, removed from the vacuum chamber, and immersed in Ar-purged Milli-Q water. 

Figure 1(b) shows an NC-AFM image of the surface in water. Strings elongated to the 

[001] direction were observed. Along cross section 1 in Fig. 1(c), subnanometer 

corrugation was observed perpendicular to the rows. The distance between the lowest 

rows, indicated by arrowheads, was approximately 0.65 nm. On some of the rows, 

periodic corrugation was observed as shown in the cross sections 2 and 3. We attributed 

the lowest rows to the oxygen atom rows, and the corrugation along the rows to H2O 

clusters. 

Figure 1: (a) Ball model of a rutile TiO2(110)-(1×1) surface. Size of the unit cell is 0.65 

nm×0.30 nm. (b) NC-AFM image of the TiO2(110) surface in pure water (15×15 nm 2 ). 

Frequency shift = +150 Hz, sample bias voltage = 0 V, peak-to-peak amplitude of the cantilever 

oscillation = 2 nm. (c) Cross sections obtained along the lines in the image. 

142

Development of Multifrequency High-speed NC-AFM in Liquid 

Y. J. Li 1,2 , K. Takahashi 1 , N. Kobayashi 1 , Y. Naitoh 1,2 , M. Kageshima 1,2 

and Y. Sugawara 1,2 

1 Department of Applied Physics, Osaka University and 2 CREST, Japan 

P.II-15 

AFM is a power tool to observe the solid-liquid interface, and it has succeeded in true 

atomic-resolution imaging on the nano-scale. Especially, the high-speed imaging is useful 

for understanding the dynamic behavior of biomolecules and the clarification of the 

physical phenomena that happen in the solid-liquid interface. In order to clarify unknown 

physical phenomena on the surface, not only the topography image and energy 

dissipation image but also elasticity including the information of surface physical 

properties is also necessary. 

Previously, we have succeeded in simultaneous imaging topography and energy 

dissipation image by our developed high-speed phase-modulation AFM (PM-AFM) in 

constant-amplitude (CA) mode [1-2]. Recently, Garcia et al have developed a theory of 

the multifrequency method in AM-AFM [3]. So far, the multifrequency method for 

measuring elasticity by high-speed PM-AFM in CA mode has not been developed yet. 

In this research, we develop the multifrequency high-speed PM-AFM in CA mode with 

the capability of simultaneous imaging elasticity in liquid. From the theory and the 

experiment, we discuss the multifrequency method in high-speed PM-AFM in CA mode. 

The high-speed elasticity image can be measured by phase shift Ф2from high-speed 

phase detector with the bandwidth of 3MHz (the second resonance mode). We 

demonstrate the multifunctional high-speed images of polymer film with the scan 

speed of 10 frames /s in water. 

(a) (b) (c) 

Figure 2 (a) topographic, (b) energy dissipation and (c) elasticity images of polymer film 

with 10frames/s. 300x300nm 2 . f1 =600 kHz, f2 =3MHz. 

[1] N. Kobayashi et, al., Jpn. J. Appl. Phys., 45 (2006) L793. 

[2] Y. Sugawara, et, al., Appl. Phys. Lett., 90 (2007) 194104. 

[3] J. R. Lozano and R. Garcia, Phys. Rev. Lett., 100 (2008) 076102. 

143

P.II-16 

Frequency-Domain and Time-Domain Analyses of Soft-Matter 

Dynamics Using Wide-Band Magnetic Excitation AFM 

Masami Kageshima, Tatsuya Ogawa, Shinkichi Kurachi, Yoshitaka Naitoh, Yan Jun Li, 

and Yasuhiro Sugawara 

Department of Applied Physics, Osaka University, Suita, Osaka, Japan. 

Dynamics analysis of nanometer-scale soft matter systems is essentical in 

understanding mechanical properties of polymer systems, function of biological 

molecules, interaction of biological systems with water molecules, etc. There are two 

major experimentally accessible quantities to represent viscoelastic properties of a system, 

a frequency response function and a step response function, each of which can be 

understood as a frequency-domain and a time-domain measurement, respectively. 

Bothapproaches can be implemented with AFM by applying a sinusoidal force with a 

varied frequency or a step force onto the AFM cantilever, given that the excitation device 

posesses a sufficient bandwidth. Here the magnetic excitation technique was extended so 

that a supurious-free and well-characterized cantilever excitation force can be applied 

onto the cantilever beyond 1 MHz [1]. As an example of a frequency-domain 

measurement, frequency-dependent viscoelasticity of a single dextran chain was already 

presented [1]. Alternatively, a step force can be applied to the cantilever using the same 

excitation system. By driving a coreless electromagnet with a wide-band constant-current 

circuit (Fig. 1), a current step of 1 A can be settled in ca. 500 ns (Fig 2(a)). Since the 

cantilever deflection makes a ringing motion mainly due to its fundamental resonance 

even in liquid, an active feedback (Q-control) circuit is employed to suppress the 

resonance (Fig. 2(b)). Results of analysis of a single polymer chain and water molecules 

interacting with a hydrophilic surface will be presented. 

Input 

Sinusoidal 

Step 

+ 

OP amp. 

- 

HV amp. 

- 

Electromagnet 

Differential amp. 

Fig. 1: Constant-current circuit and electromagnet. 

[1] M. Kageshima, T. Chikamoto, T. Ogawa, Y. 

Hirata, T. Inoue, Y. Naitoh, Y. J. Li, and Y. 

Sugawara, Rev. Sci. Instrum. 80 (2009) 023705. 

+ 

Cantilever 

Magnet 

144 

Iuput (V) 

(a) 

0.08 

0.03 

-0.02 

-1 0 1 

(b) Time (microsec.) 

input 

deflection 3 nm 

0.4 

-0.1 

-0.6 

Current (A) 

0 1 2 3 4 5 

Time (msec.) 

Fig.2: (a) Current profile and (b) Qsuppressed 

cantilever deflection in water.

Noncontact observation in liquid with van der Pol-type FM-AFM 

M. Kuroda 1 , H. Yabuno 2 , T. Someya 3 , R. Kokawa 4 , and M. Ohta 4 

1 National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan 

2 Department of Mechanical Engineering, Keio University, Yokohama, Japan 

3 Mitsubishi Heavy Industries Ltd., Hiroshima, Japan 

4 Analytical & Measuring Instruments Division, Shimadzu Corp., Kyoto, Japan 

Atomic force microscopy (AFM) is crucial for nanobiotechnology 

studies. Observing bio-related samples 

in liquids using AFM is important, but deformable, 

uneven, and easily damaged surfaces of such 

specimens require non-contact AFM observation. 

For probe-cantilever excitation, the eigenfrequency 

must be estimated based on frequency response 

characteristics for the external excitation method. It 

cannot estimate the probe cantilever’s eigenfrequency 

precisely because of many spurious peaks (Fig. 1). But, 

the self-excitation method needs fine adjustment of the 

linear feedback gain near the oscillation limit by an 

automatic gain controller (AGC) to prevent the probe 

cantilever from touching the sample surface: 

oscillation can easily halt, disabling the observation. 

In solving those problems, van der Pol-type (vdP) 

self-excited oscillation represents a positive use of 

nonlinearity [1–2]. Along with conventional positive 

linear velocity feedback for self-excited oscillation, 

vdP self-excited oscillation is realized by adding 

nonlinear feedback proportional to the squared 

deflection times the velocity. With the eigenfrequency 

component alone (Fig. 2), vdP self-excited oscillation 

guarantees existence of a stable stationary amplitude. 

Increased nonlinear feedback gain reduces the response 

amplitude but retains the high gain linear feedback. 

A 19-nm-high SiN4 surface pattern with 3 μm pitch 

was observed in pure water using vdP-AFM (Fig. 3). 

The smaller probe-cantilever vibration amplitude than 

the probe-cantilever – sample gap verifies noncontact 

observation. The vdP-AFM takes sample surface 

images with equal accuracy to that of contact-mode 

AFM. Even in liquid, oscillation continues. 

[1] H. Yabuno et al. Nonlinear Dynamics 54, 137 (2008). 

[2] M. Kuroda et al. Journal of System Design and Dynamics 2-3, 886 (2008). 

145 

P.II-17 

Figure 1: Frequency response 

curve in pure water (External 

excitation method) 

f=54.4 kHz 

Figure 2: Power spectrum in pure 

water (vdP self-excited oscillation 

method) 

Figure 3: Sample observed in pure 

water by vdP FM-AFM

P.II-18 

Development of a NC – AFM for Ambient and Liquid Environments 

Haider I. Rasool 1 , Shivani Sharma 1 , James K. Gimzewski 1,2,3 

1 Department of Chemistry and Biochemistry, University of California – Los Angeles, USA 

2 California NanoSystems Institute, 570 Westwood Plaza, Los Angeles, USA. 

3 International Center for Materials Nanoarchitectonics (MANA), Tsukuba, Japan 

High resolution Non – Contact Atomic Force Microscopy imaging has been 

achieved by various groups in both ambient and liquid environments [1] – [3]. The recent 

success of NC – AFM in these “low – Q” environments has been attributable to the 

development of low noise detection schemes for measuring small amplitude deflections. 

We describe current research on the development of a robust home – built scanning probe 

microscope with an incorporated low noise all fiber interferometer deflection sensor for 

imaging in both ambient and liquid environments. The current design of the scanning 

probe microscope in its AFM configuration is depicted in Figure 1 (a). 

The developing instrument has been used to image various biological species in 

both ambient and liquid environments in different imaging modes. In particular, our 

group has been successful in imaging isolated human saliva exosomes fixed to a mica 

substrate in both air and buffer solution. Both amplitude and phase modulation imaging 

have been accomplished on these samples under ambient conditions. Using constant 

excitation phase modulated imaging, a simultaneous mapping of topography and energy 

dissipation has been possible at a constant average tip sample force. Figure 1(b) shows a 

typical image of the topography of an isolated exosome. 

a) b) 

Figure 1: The above images show (a) the design of the home built microscope and (b) a PM – 

AFM image of a human saliva exosome. 

[1] T. Fukuma, M. Kimura, K. Kobayashi, K. Matsushige, and H. Yamada. Rev. Sci. Instrum. 76, 053704 

(2005). 

[2] B.W. Hoogenboom, H.J. Hug, Y. Pellmont, S. Martin, P.L.T.M. Frederix, D. Fotiadis,and A. Engel. 

Appl. Phys. Lett. 88, 193109 (2006). 

[3] T. Fukuma, and S. Jarvis. Rev. Sci. Instrum. 77, 043701 (2006). 

146

P.II-19 

Cantilever Holder Design for Spurious-Free Cantilever Excitation in 

Hitoshi Asakawa 1 and Takeshi Fukuma 1,2 

Liquid by Piezoactuator 

1 Frontier Science Organization, Kanazawa University, Japan 

2 PRESTO, JST, Japan 

Recent advancement in frequency modulation atomic force microscopy (FM-AFM) 

has enabled us to obtain atomic and molecular resolution images in liquid, which has 

encouraged us to explore the possibilities of FM-AFM application in biological research. 

In liquid-environment FM-AFM, a method for cantilever excitation is particularly 

important for ensuring the stability and accuracy in imaging and quantitative force 

measurements. This is because FM-AFM utilizes a cantilever deflection signal not only 

for obtaining a distance feedback signal (i.e., frequency shift signal) but also for 

producing a cantilever excitation signal. Although the cantilever excitation with a 

piezoactuator is most commonly used, the method typically results in an excitation of 

spurious resonances around the natural resonance frequency of a cantilever due to the 

uncontrolled propagation of acoustic waves from a piezoactuator to the cantilever (Fig. 

1(a)). 

In order to suppress the influence of the spurious resonances, we propose a cantilever 

holder design, where the propagation of an acoustic wave is restricted the surrounding 

boundaries between two materials having significantly different specific acoustic 

resistances (ρ·c [kg/m 2 ·s]). In our design, an acoustic wave is greatly reduced by the 

reflection at the boundary between a piezoactuator (PZT, ρ·c=35×10 6 ) and its supporting 

material (PEEK, ρ·c=3.3×10 6 ). Then the remaining acoustic wave is further reduced by 

the reflection at the boundaries between the PEEK part and other components such as a 

cantilever support (stainless steel 316, ρ·c=36×10 6 ) and an optical window (glass, 

ρ·c=11×10 6 ). Figure 1 demonstrates the remarkable effect of the acoustic boundaries for 

suppressing spurious vibrations induced by the acoustic waves. 

a) b) 

Figure 1: Frequency responses of cantilever oscillation amplitude induced by a piezoactuator. 

(Excitation amplitude, : 0.5 V, : 1 V, : 1.5 V). Supporting materials for a piezoactuator: (a) 

stainless steel 316 and (b) PEEK. 

147

The different faces of the calcite (10-14) surface 

Jens Schütte 1 , Lutz Tröger 1 , Philipp Rahe 1 , Ralf Bechstein 1,2 and Angelika Kühnle 1 



P.II-20 

Although atomic resolution has been achieved on calcite (10-14) using static atomic force 

microscopy (AFM) in liquid environment since 1992 [1], it is still unclear whether the 

surface reconstructs or not. Most experiments carried out so far using static AFM in 

liquids show a reconstruction of the surface in the [-4-21] direction, called “row pairing” 

[2,3]. Besides the row pairing, several results exist, showing a (2 x 1) reconstruction [4]. 

This reconstruction has been discussed rather controversial and was explained by the 

adsorption of water. 

Here, we present an NC-AFM study carried out in ultra-high vacuum of the in-situ 

cleaved calcite (10-14) surface showing real atomic resolution (see Fig. 1 (a)) and a 

detailed research of the many “faces” of the surface. It is shown, that the (2 x 1) 

reconstruction (see Fig. 1 (b)) of the surface is not induced by water adsorption, but 

imaging the surface with a (2 x 1) reconstruction is strongly influenced by the tip-sample 

distance. 

a) b) 

Figure 1: NC-AFM frequency shift images of calcite (10-14). In (a) the surface shows “row 

pairing” in [-4-21] direction, however, no (2 x 1) reconstruction is seen. The average detuning is - 

9.3 Hz. In (b) a (2 x 1) reconstruction is clearly visible. The average detuning is -12.1Hz. 

[1] P. E. Hillner et al., Ultramicroscopy 42-44, 1387 (1992). 

[2] S. L. S. Stipp et al., Geochim. Cosmochim. Ac. 58, 3023 (1994). 

[3] F. Ohnesorge and G. Binnig, Science 260, 1451 (1993). 

148

P.II-21 

Manipulation Mechanism of Single Cu Atoms on Cu(110)-O Surface 

with Low Temperature Non-Contact AFM 

Y. Kinoshita, T. Satoh, Y. J. Li, Y. Naitoh, M. Kageshima and Y. Sugawara 

Department of Applied Physics, Graduate School of Engineering, Osaka University Osaka, Japan 

Atom manipulation is a fascinating technique for artificially fabricating nanometer 

scale structures. Recently using non-contact atomic force microscopy (NC-AFM), the 

well-controlled manipulations of individual atoms [1] or molecules on surfaces were 

demonstrated. Furthermore, using the force spectroscopy techniques, atomic force-vector 

field [2] or driving forces involved in a single atom manipulation [3] were determined. 

More recently our group have successfully manipulated single topmost Cu atoms 

laterally on Cu(110)-O surfaces and identified manipulation modes (pulling or pushing) 

from the AFM feedback signals. At the same time, we found that the atom species (Cu or 

O) of the tip apex changes not only the AFM topographic images drastically but also the 

mode for lateral manipulation of a Cu atom on the surface. However the difference in tipsample 

potential energy from the species of the tip apex has still been unclear. In this 

study, we investigate the potential distributions depending on the species of the topmost 

atom on the tip and clarify the different mechanisms for lateral manipulation of Cu atoms 

All measurements were performed in ultrahigh vacuum at 78 K. By using the image 

tracking scheme, the precise positioning of the tip with small drift velocity

P.II-22 

Simultaneous NC-AFM/STM Imaging of the Surface Oxide Layer on 

Cu(100) and Identification of Lattice Sites 

Mehmet Z. Baykara 1 , Todd C. Schwendemann 1,2 , Eric I. Altman 2 , Udo D. Schwarz 1 

1 



2 

Department of Chemical Engineering and Center for Research on Interface Structures and Phenomena 


Exposure of Cu(100) to molecular oxygen at elevated temperatures leads to the (2√2 × 

√2) R45 o missing row reconstruction pictured in Fig. 1a, where oxygen atoms are found 

to sit nearly co-planar with the Cu atoms in the outermost layer [1]. Since O and Cu 

atoms occupy sublattices with different symmetries, this surface represents an ideal 

model where atoms responsible for contrast formation in NC-AFM and STM imaging 

modes can be identified by symmetry alone. Using our homebuilt low temperature, 

ultrahigh vacuum atomic force microscope [2], we have obtained simultaneously 

recorded NC-AFM and tunneling current images on the oxidized Cu(100) surface. 

Comparing the visual distinctions between the two images, bright features in the images 

are assigned to specific locations on the surface. In particular, metal tips are found to 

interact strongly with bridge sites between two under-coordinated oxygen atoms, leading 

to a rectangular unit cell contrast in high-resolution NC-AFM images (Fig. 1b), whereas 

simultaneously collected tunneling current data exhibit an elongated hexagonal unit cell, 

which is assigned to surface Cu atoms (Fig. 1c). These measurements demonstrate the 

ability of multi-dimensional, atomic-resolution scanning probe microscopy to identify 

adsorption sites on oxide surfaces. 

Figure 1: a) Model of the (2√2 ×√2) R45 o O-induced reconstruction of Cu(100). The grey balls 

represent O, the light orange surface Cu, and the darker orange second layer Cu. b) NC-AFM 

image acquired with a frequency shift of -0.95 Hz at T = 6 K and c) simultaneously acquired 

tunneling current image collected at a sample bias of -0.4 V. 

[1] M. C. Asensio et al, Surf. Sci. 236, 1 (1990). 

[2] B. J. Albers et al, Rev. Sci Instrum. 79, 033704 (2008). 

150

nc-AFM Investigations of Metal Nanoclusters on α-alumina 

P.II-23 

K Venkataramani 1 , M C R Jensen 1 , M Reichling 2 , F Besenbacher 1 , and J V Lauritsen 1 

1 Interdisciplinary Nanoscience Center (iNANO), Department of Physics, Aarhus University, Denmark 

2 Department of Physics, University of Osnabrück, Germany 

AFM operated in the non-contact mode has proved very successful in imaging insulating 

surfaces with atomic resolution and recently has also proved the capability to image 

supported nanoclusters. Insight from studies of such systems may be important for a 

better and much needed understanding of heterogeneous catalysis, since most catalysts 

consists of nanoclusters dispersed on insulating metal oxide substrate. It is well known 

that while imaging nanoclusters with nc-AFM, the tip apex is one of the main limiting 

factors in the topography imaging mode i.e. constant detuning mode (Z) but a 

complementary scanning mode, the constant height mode (df), has surprisingly been 

shown to give a more precise estimation of lateral cluster shape [1]. In this study, using 

nc-AFM, we present high resolution topography images of Cu nanoclusters supported on 

clean (Fig. 1(a)) and pre-hydroxylated α-Al2O3(0001) surfaces and can thereby report in 

great detail on cluster growth, thermal stability and morphology. Further, by scanning in 

constant height mode, we obtained high quality images of the top (111) facet of Cu 

nanoclusters revealing a clear hexagonal shape (Fig. 1(b)). This equilibrium shape 

determined solely from AFM can be related to the adhesion energy (Eadh) by the equation 

derived from the Wulff-Kaichew reconstruction (Fig. 1(c)) [2], which gives an 

understanding of the strong cluster-substrate binding. Further, this study was extended to 

investigate the growth of Ni nanoclusters and our initial results revealed nanoscale 

ordering of Ni clusters at room temperature. 

Figure 1: (a) Topography image of supported Cu nanoclusters on α-Al2O3(0001) surface. (b) Cu 

clusters imaged in constant height mode. (c) Schematic representation of Wulff-Kaichew 

reconstruction and the equation relating free energy of cluster facet (γmetal(i)) with Eadh. 

[1] C. Barth, O. H. Pakarinen, et al. Nanotechnology 17, S128-S132 (2006). 

[2] C. R. Henry. Surface Science Reports 31, 231-325 (1998). 

151

Atom-resolved AFM studies of the polar MgAl2O4 (001) surface 

Morten K. Rasmussen, Jeppe V. Lauritsen, and Flemming Besenbacher 

Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, Denmark 

P.II-24 

Magnesium-aluminate spinel (MgAl2O4) has many interesting properties and 

applications, among other things the use as a support for catalysts. In particular, MgAl2O4 

in a porous form is a support material for the important Ni-based catalyst used for steam 

reforming of methane, which today is the most common method of producing bulk 

hydrogen. A study of the clean spinel is thus of very great importance to understand the 

role of the support, and still almost no surface science studies on the MgAl2O4 surface 

have been presented due to the insulating nature of the material. When constructing a 

surface model one must consider the fact that the spinel (001) surface is polar and the 

surface consequently has to be modified somehow to cancel out or compensate for this. 

Additionally, it is well known that the AFM tip can pick up material from the surface, 

and this material then can change the polarity of the nano-apex which leads to variations 

in the AFM contrast seen in atom-resolved images and reveals the individual sub lattices 

[1, 2]. In this study we observe from atom-resolved AFM images that the MgAl2O4 (001) 

surface may be imaged in two distinctly different contrast modes revealing the anion or 

cation sub-lattice. Tentative structural characterizations from the AFM studies suggest a 

stoichiometric bulk like termination. Stabilization mechanism may then include 

relaxations in the crystal structure below the topmost layer which cannot be probed by 

AFM, hence surface x-ray diffraction is used to complement the AFM data. 

a) b) 

Figure 1: (a) Atom resolved non-contact AFM image (4nm×4nm) of the clean MgAl2O4 (001) 

surface imaged under UHV conditions together with (b) a ball model of the surface. The surface 

appears to be Mg-terminated and near stoichiometric with a low atomic defect density less than 

0.1ML. 

[1] Lauritsen, J.V., et al., Chemical identification of point defects and adsorbates on a metal oxide 

surface by atomic force microscopy. Nanotechnology, 2006. 17(14): p. 3436. 

[2] Enevoldsen, G.H., et al., Noncontact atomic force microscopy studies of vacancies and hydroxyls 

of TiO[sub 2](110): Experiments and atomistic simulations. Physical Review B (Condensed 

Matter and Materials Physics), 2007. 76(20): p. 205415-14. 

152

P.II-25 

Contrast formation on cross-linked (1x2) reconstructed titania (110) 

Hans H. Pieper 1 , Stefan Torbrügge 1,2 , Stephan Bahr 1,2 , Krithika Venkataramani 1,3 , 

Angelika Kühnle 1 and Michael Reichling 1 


2 present address: SPECS GmbH, Voltastrasse 5, 13355 Berlin, Germnay 


In NC-AFM imaging, the tip structure plays a prominent role in atomic contrast 

formation. It is, for instance, possible to image the cationic or the anionic sub-lattice of 

CaF2(111) by changing the tip termination [1]. For the unreconstructed rutile TiO2 (110) 

at least a third mode is known [2]. 

Here, we investigate the cross-linked (1x2) surface reconstruction of rutile 

TiO2(110), which has been studied both with STM and NC-AFM, however, the atomic 

structure is still discussed controversially. We present NC-AFM results, which will be 

interpreted with respect to tip termination and tip-surface distance. A comparison with 

existing models provides strong evidence for one of these models. 

Figure 1: Three consecutive images of the cross-linked (1x2) titania surface taken with different 

tip terminations. The left image is taken with a positive tip termination. A contact with the sample 

leads to a negative tip termination (middle image). The tip in the right picture is unidentified. 

Figure 2: High resolution measurements are in good agreement with the surface model suggested 

by Bennett [3] as shown to the right. 

[1] C. Barth et al. J. Phys.: Condens. Matter 13, 2061 (2001) 

[2] G.H. Enevoldsen et al. Phys. Rev. B 76, 205415 (2007) 

[3] R.A. Bennett et al. Phys. Rev. Lett. 82, 3831 (1999) 

153

P.II-26 

Nano volcanoes – the surface structure of antimony-doped TiO2(110) 

Ralf Bechstein 1,2 , Mitsunori Kitta 3 , Jens Schütte 1 , Hiroshi Onishi 3 , and Angelika Kühnle 1 



3 Department of Chemistry, Kobe University, Rokko-dai, Nada-ku, Kobe 657-8501, Japan. 

Titanium dioxide constitutes a very prominent and widely used example of a wide band 

gap photocatalyst [1]. Upon codoping with chromium and antimony, rutile titania has 

shown photocatalytic activity under irradiation with visible-light. The reactivity has been 

found to be optimized in slight excess of antimony. Even larger antimony excess has 

been observed to again result in reduced photocatalytic activity [2]. 

Here, we address the role of excess antimony in chromium and antimony codoped titania 

by studying the influence of antimony on the surface structure of rutile TiO2(110) using 

high-resolution NC-AFM. All findings draw a picture of weakly integrated antimony in 

antimony-doped titania indicating why an excess of antimony beyond the optimum ratio 

is unfavourable for photocatalytic applications. Moreover, the presented study revealed 

another interesting phenomenon: It seems to be possible to create nano-sized holes with 

depths ranging from a few up to more than hundred monatomic steps in a controlled way 

by tuning the annealing parameters of antimony-doped TiO2(110) [3]. This might be an 

appropriate strategy for creating nano-patterned surfaces with macroscopic techniques. 

(a) (b) 

Figure 1: NC-AFM topography images of antimony-doped TiO2(110) obtained after annealing at 

1100 K. Holes with a diameter of about 50 nm and a depth of more than 30 nm are created (a). 

Typically, the holes are surrounded by small islands (b). This results in an appearance that 

resembles a volcano-like shape. 

[1] A. Fujishima, X. Zhang, and D. A. Tryk, Surf. Sci. Rep. 63, 515 (2008). 

[2] H. Kato and A. Kudo, Catal. Today 78, 561 (2003). 

[3] R. Bechstein et al., submitted to Nanotechnology (2009). 

154

P.II-27 

Non-contact scanning nonlinear dielectric microscopy imaging of TiO2 

Nobuhiro Kin and Yasuo Cho 

(110) surfaces 

Research Institute of Electrical Communication, Tohoku University, Sendai, Japan 

Scanning nonlinear dielectric microscopy (SNDM) is a pure electrical method that is 

used for detecting the local anisotropy of dielectric materials and measuring ferroelectric 

polarization with sub-nanometer resolution [1]. Recently, we have developed non-contact 

SNDM (NC-SNDM) with a height control technique that makes use of the detection of a 

higher-order nonlinear dielectric constant (ε (4) signal). We have already succeeded in 

observing the typical Si (111) 7 × 7 atomic structure [2]. An interesting potential future 

application of NC-SNDM is in the imaging of insulating materials such as TiO2, SrTiO3 

(STO), Al2O3, SiO2, and MgO. It is well known that TiO2 becomes an n-type 

semiconductor after high-temperature annealing under ultra-high vacuum conditions. Due 

to its simplicity, the atomic structure of TiO2 can be examined easily as compared to that 

of other materials such as STO, which comprises three types of atoms. Moreover, TiO2 

has been studied extensively because it is well known and widely used as a superior 

substrate for catalysts. Therefore, in this study, we selected TiO2 (110) as our initial 

specimen for investigating insulating materials. We have demonstrated that atomresolved 

images of a TiO2 (110) surface can be obtained by NC-SNDM. Considering 

both the topography and the electrical dipole moment (ε (3) image) [2], the parallel bright 

stripes in the [001] direction should correspond to Ti 4+ . The protrusion on the bright 

stripes corresponds to Ti 3+ , and the other protrusion on the dark rows corresponds to H + 

due to water. It should be noted that there exist other possibilities; these will be analyzed 

in detail in the future. 

a) b) 

Figure 1: (a) NC-SNDM image of TiO2 (110) recorded using the ε (4) signal as feedback. The 

scan resolution is 30 nm × 30 nm. (b) STM image of TiO2 (110) having the same scan resolution. 

A positive voltage of 1.2 V is applied to the bottom of the sample. 

[1] Y. Cho, A. Kitahara, and T. Saeki. Rev. Sci. Instrum. 67, 2297 (1996). 

[2] Y. Cho and R. Hirose. Phys. Rev. Lett. 99, 186101 (2007). 

155

156 

P.II-28 

Characterizations of Carbon Material by Non-contact Scanning 

Non-linear Dielectric Microscopy 

Shin-ichiro Kobayashi and Yasuo Cho 

Research Institute of Electrical Communication, Tohoku University, Sendai , Japa 

Recently a new and uniquely promising technique, the "non-contact scanning 

non-linear dielectric microscopy" (NC-SNDM) was introduced [1,2]. Since this technique has 

high sensitivity to variations in the capacitance, we were able to use it to visualize the domain 

structure in ferroelectric or carrier in flash memory. The graphite or fullerene (C60) are paied to 

attention because of the unique properties and the candidate of high performance device. In this 

study, we present SNDM images of the graphite (HOPG) and C60 on Si(111)-7x7 (7x7) surface 

by the NC-SNDM to understand the properties of carbon materials with new viewpoint. C60 

thin-film on 7x7 surfaces were fabricated by the deposition method under the ultra high vacuum 

Feedback signal to observe topography or SNDM images was utilized by 2ω amplitude signal. 

Figure 1 shows ω amplitude image of HOPG. The contrast is inverted to make easily 

to understand the image. The clear honeycomb structure is observed. In addition, the three 

saddle points in the single hexisagonal ring are also recognized. This means that the NC-SNDM 

can detect the A or B site originated from the difference of the band structure. These results are 

similar to those of the STM. This indicates that the origin of the SNDM signal for the HOPG is 

similar to that of the STM. Figure 2 shows the topography of C60 for 1ML on 7x7 surface. The 

insert is the expanded image of Fig. 2. As 

is seen from the insert, the internal 

structures in some C60 molecules by the 

NC-SNDM are observed. This structure is 

similar to the charge distribution for the 

LUMO orbital. Furthermore, investigating Figure 1 The ω amplitude image for HOPG the 

phase reversal in ω phase image for 

various coverage of C60 on 7x7 surface, we 

could guess the characterization of the 

bonding between C60 and 7x7 surface. The 

details of the observed SNDM images are 

described in the presentation. 

[1]R. Hirose, K.Ohara and Y. Cho, Figure 2 Topography of C60 on 7x7 surface for 1ML 

Nanotechnology. 18 (2007), p084014. [2] Y. Cho and R. Hirose, PRL 99 (2007), p186101.

P.II-29 

Local Dielectric Spectroscopy of Nanocomposite Materials Interfaces 

M. Labardi 1 , D. Prevosto 1 , S. Capaccioli 1,2 , M. Lucchesi 1,2 and P.A. Rolla 1,2 

1 INFM-CNR, LR polyLab, Largo Pontecorvo 3, 56127 Pisa, Italy 

2 Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy. 

Dielectric spectroscopy (DS) has revealed especially successful to disclose structural 

properties of polymeric materials, like e.g. their glass transition and structural relaxation 

phenomena. Local probe DS [1] combines the high spatial resolution of frequency 

modulation electrostatic force microscopy (FM-EFM) with the physical insight typical of 

DS, being firstly demonstrated on homogeneous poly-vinyl-acetate (PVAc) films under 

vacuum [1]. In essence, a sinusoidal potential at frequency fmod is applied to a conductive 

probe and the induced modulation of the resonant frequency shift Δfres is measured by 

dual-phase lock-in technique, referenced at 2fmod. Phase delay indicates dielectric loss due 

to polarization relaxation occurring with characteristic time τR ~ 1/ fmod [1]. 

We apply local DS to address the influence of inorganic inclusions on structural 

relaxation of polymers. A PVAc thin film (30 nm) with a dispersion of a layered silicate 

(montmorillonite, MMT) was spin-coated onto Au, and partially scratched away to 

expose the metal, to obtain a reference surface (Fig. 1a). Presence of inorganic layers on 

the surface is evident from the TappingMode TM phase image (Fig. 1b). Conventional FM- 

EFM (Veeco Lift mode TM in controlled atmosphere [2] and temperature) shows materials 

contrast (Fig. 1c), independent of T. In Fig. 1d-f, dielectric loss maps at T = 50, 60, 70°C 

show highest contrast at T = 60°C for the used fmod = 130 Hz, corresponding to τR ~ 7-8 

ms. Dielectric contrast at inclusions can also be studied (Fig. 1e, arrow). 

Financial support from INFM-CNR “Seed 2007” project is acknowledged. 

Figure 1: a) Topography of a PVAc/MMT thin film (left) on Au (right). b) Phase image showing 

the location of inorganic layers (arrow). c) Δfres map. d)-f) Dielectric loss maps at T = 50,60,70°C. 

[1] P.S. Crider, M.R. Majewski, J. Zhang, H. Oukris, N.E. Israeloff, Appl. Phys. Lett. 91, 013102 (2007). 

[2] M. Lucchesi, G. Privitera, M. Labardi, D. Prevosto, S. Capaccioli, P. Pingue, J. Appl. Phys. 105, 

054301 (2009). 

157

P.II-30 

Probing Local Bias-Induced Phase Transitions on the Single Defect 

Level: from Imaging to Deterministic Mechanisms 

N. Balke 1 , S. Jesse 1 , P. Maksymovych 1 , Y.H. Chu 2 , R. Ramesh 2 , S. Choudhury 3 , L.Q. 

Chen 3 , and S.V. Kalinin 1 

1 Oak Ridge National Laboratory, Oak Ridge, TN 37831 

2 Dept. of Physics and Dept. of Mat. Sci. and Eng., University of California, Berkeley, CA 

3 Dept. of Mat. Sci. and Eng., Pennsylvania State University, University Park, PA 16802 

Force-induced processes such a molecular unfolding spectroscopy and NC-AFM 

atomic manipulation now underpin many areas of physics and biology. Here, I discuss 

recent progress on probing local bias-induced phase transitions in ferroelectrics and 

electrochemical systems. Bias-induced phase transitions are controlled by structural 

defects that act both as the local nucleation centers and the pinning centers for moving 

domain walls. Future progress necessitates understanding of polarization switching 

mechanisms on the single structural or morphological defect level. In this talk, I will 

present results on local studies of polarization reversal mechanisms in ferroelectrics [1-2]. 

The direct imaging of a single nucleation center on the sub-100 nanometer level is 

demonstrated [3]. By using switching spectroscopy Piezoresponse Force Microscopy on 

systems with engineered defect structures and phase-field modeling, we demonstrate that 

deterministic that mesoscopic polarization switching mechanisms on single 1D and 2D 

defects can be determined. We develop a framework to link the modeling results to 

experimental observations using neural-network based recognition. The future potential 

for atomistic studies is discussed. Research was supported by the U.S. Department of 

Energy Office of Basic Energy Sciences Division of Scientific User Instruments and was 

performed at Oak Ridge National Laboratory which is operated by UT-Battelle, LLC. 

Figure 1: (a) Surface topography and (b) SS-PFM nucleation bias map of BiFeO3 24deg (100) 

bicrystal grain boundary (GB). Each point in (b) is a hysteresis loop. (c) Ferroelectric switching 

properties across the interface. 

[1] S.V. Kalinin, B.J. Rodriguez, S. Jesse, Y.H. Chu, T. Zhao, R. Ramesh, E.A. Eliseev, and A.N. 

Morozovska, PNAS 104, 20204 (2007). 

[2] S. Jesse, B.J. Rodriguez, A.P. Baddorf, I. Vrejoiu, D. Hesse, M. Alexe, E.A. Eliseev, A.N. Morozovska, 

and S.V. Kalinin, Nature Materials 7, 209 (2008). 

[3] S.V. Kalinin, S. Jesse, B.J. Rodriguez, Y.H. Chu, R. Ramesh, E.A. Eliseev and A.N. Morozovska, Phys. 

Rev. Lett. 100, 155703 (2008) 

158

P.II-31 

Polarization-dependent electron tunneling into ferroelectric surfaces 

Peter Maksymovych 1 , Stephen Jesse 1 , Pu Yu 2 , Ramamoorthy Ramesh 2 , Arthur P. 

Baddorf 1 , Sergei V. Kalinin 1 

1 Center for Nanophase Materials Sciences, Oak Ridge National Laboratory 

2 Department of Physics and Dept. of Materials Science, University of California, Berkeley 

Electron tunneling underlies the operation of numerous devices relevant to 

information technology and has been proposed in futuristic applications for energy 

harvesting and quantum computing. Replacing a conventional insulator in the tunnel 

junction with electronically correlated materials can yield new types of electronic 

functionality. In one such concept, dubbed ferroelectric tunneling, the tunneling barrier 

height is controlled by the polarization of a ferroelectric oxide, enabling non-volatile 

conduction states that can be switched with electric field. Although ferroelectric 

tunneling has been a recent focus of a number of theoretical studies, aiming to unveil the 

interfacial behaviors of the ferroelectric order parameter, a convincing experimental 

demonstration of this phenomenon has been lacking. The key challenges are to find a 

material system that simultaneously satisfies the dimensional constraints for tunneling 

and ferroelectricity, as well as to assure that the conductance is not dominated by 

extrinsic effects due to charge injection and filamentary conduction, which is ubiquitous 

in complex oxides. 

In this talk we will demonstrate a highly reproducible polarization control of local 

electron transport through thin Pb(Zr0.2Ti0.8)O3 film. Despite being 30 nm thick, 

conductive atomic force microscopy revealed that the film possessed spatially and 

temporally reproducible local conductivity. Fowler-Nordheim electron tunneling was 

identified as the conductance mechanism, likely enabled by strong electric field in the 

sub-surface region (excess of 10 6 V/cm) created by the relatively sharp metal tip. Local 

conductance exhibited strong hysteresis depending on the probed bias range. Using a 

newly-developed combination of piezoresponse force and conductive atomic force 

microscopy, we have, for the first time, directly correlated local events of ferroelectric 

and resistive switching [1]. The large polarization of the studied film resulted in as high 

as 500-fold enhancement of the FN-tunneling conductance upon ferroelectric switching, 

sufficient to demonstrate a local non-volatile memory function. 

The physical mechanism of the observed effect was traced to the polarizationdependence 

of the height and possibly width of the metal-ferroelectric Schottky barrier. 

Our measurements have thus extended a well-known polarization dependence of surfacepotential 

on ferroelectric materials from Kevlin probe force microscopy to demonstrate 

local control of electron transport through such materials. Variable-temperature 

measurements and local effects due to dielectric non-linearities will also be discussed. 

[1] P. Maksymovych, S. Jesse, P. Yu, R. Ramesh, A. P. Baddorf, S. V. Kalinin, Science (2009) in review. 

159

Local ferroelectric and magnetic investigations on 

multiferroic thin films 

P.II-32 

Ulrich Zerweck 1 , D. Köhler 1 , P. Milde 1 , Ch. Loppacher 2 , S. Geprägs 3 , S.T.B. Goennenwein 

3 , R. Gross 3 , L.M. Eng 1 

1 Institute of Applied Photophysics / Technische Universität Dresden, 01062 Dresden, Germany 

2 L2MP, Université Paul Cézanne, 13397 Marseille , France 

3 Walther-Meißner-Institut / Bayerische Akademie der Wissenschaften, 85748 Garching, Germany. 

Multiferroic materials, which combine ferroelectric and ferromagnetic properties, are 

promising candidates for novel nanoscale switching and memory devices, especially if 

there is a coupling between those properties. 

Here, we present low-temperature noncontact atomic force microscopy (nc-AFM) - in 

particular magnetic force microscopy (MFM) and Kelvin probe force microscopy 

(KPFM) - investigations of multiferroic BiCrO3 and BiFeO3 thin films prepared by 

pulsed laser deposition (PLD) as described in [1]. In addition to the nc-AFM 

investigations, piezoresponse force microscopy (PFM) was used to study the ferroelectric 

switching behaviour of the thin films. 

Although the separation of magnetic and ferroelectric properties is nontrivial due to the 

long range nature of both of the related forces, we were able to clearly separate the two 

different domain types by simultaneously running KPFM and MFM. 

[1] S. Geprägs et al., Phil. Mag. Lett. 87: 141 (2007). 

160

Magnetic Resonance Force Microscopy in Anisotropic Systems 

Thomas Fan and Vladimir I. Tsifrinovich 1 

1 Department of Physics, Polytechnic Institute of NYU, Brooklyn, USA 

161 

P.II-33 

We have developed theory for the detection of a single spin S≥1 using magnetic 

resonance force microscopy (MRFM), a subset of atomic force microscopy. The 

anisotropy caused by the crystalline field is taken into account. The MRFM signal (i.e. 

the frequency shift of the cantilever vibrations) in the oscillating cantilever-driven 

adiabatic reversals technique is computed using a semi-classical approach: the spin is 

treated quantum mechanically, and the cantilever vibrations classically. We have shown 

that the MRFM signal for spin S≥1 is the same as for the spin S=1/2. We have obtained 

the analytical estimate for the half-width of the MRFM signal.

P.II-34 

Sub-10 nm resolution in Magnetic Force Microscopy (MFM) at ambient conditions 

Ö. Karcı 1,2 , H. Atalan 1 , M. Dede 1 , Ü. Çelik 3 , A.Oral 4 

1 NanoMagnetics Instruments Ltd., 266 Banbury Road, Oxford OX2 7DL, UK. 

2 Hacettepe University, Department of Nanoscience & Nanomedicine, Beytepe, Ankara, 

Turkey 

3 Istanbul Technical University, Department of Material Science, Istanbul, Turkey 

4 Sabanci University, Faculty of Engineering & Natural Sciences, 34956 Istanbul, Turkey 

aoral@sabanciuniv.edu 

We describe designs of high resolution Magnetic Force Microscopes, which can achieve 

better than 10 nm resolution in magnetic imaging even in ambient conditions. We 

developed two different MFMs, which can both achieve better than 10 nm lateral 

resolution, using commercially available, off the shelf, magnetically coated cantilevers. 

Both MFMs have been optimized to have low noise, using RF modulation of the laser 

diode. One of the instruments is designed for low temperature use, 300 mK-300 K using 

low noise fiber optic interferometer & alignment free cantilevers. The other MFM is 

designed to operate in ambient conditions and employ a beam deflection pickup with 

optimized noise performance. Both MFMs can also be operated in bimodal operation, 

using first and second resonance of the magnetically coated cantilever for topography and 

magnetic contrast. One of the typical images obtained at ambient conditions with the 

MFMs on Seagate’s 394 Gbpsi harddisk is given below. 

162

P.II-35 

Enhancement of the Exchange-bias Effect based on Quantitative 

Magnetic Force Microscopy Results. 

N. Pilet 1 , M.A. Marioni 1 , S. Romer 1 , N. Joshi 2 , S. Özer 2 and H.J. Hug, 1,2 

1 Empa, Swiss Federal Institute for Materials Testing and Research, CH-8600 Duebendorf, Switzerland, 

2 Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland 

Exchange biasing (EB) causes a lateral shift of the magnetization vs. field curve in 

antiferromagnetic-ferromagnetic (AF-F) thin-film structures. It is largely believed that 

EB arises from linking the magnetization of the F to that of (pinned) uncompensated 

spins (UCS) in the AF. In the present work we are able to measure the local density of 

UCS on the scale of 20 nm, using quantitative magnetic force microscopy (qMFM). With 

quantitative results at this lateral resolution, it becomes possible to resolve and measure 

the UCS underneath each F domain at scales comparable to the grain size. The average 

density of UCS around 20% of that expected for a full monolayer of spins is considerably 

higher than expected from the measured exchange field and local values may reach 

100%. We found that UCSs coupling antiparallel to the F magnetization stabilize its 

orientation, i.e. they are biasing [1,2]. Locally, UCS oriented parallel to the F 

magnetization were found. These have an antibiasing effect and are hence expected to 

weaken the exchange field. We hypothesized that such anti-biasing arises from 

conflicting exchange interaction between the F-layer and AF-grains, and between AFgrains 

themselves. Exchange-bias systems grown with suppressed inter-granular coupling 

in the AF-layer proved our hypothesis to be correct. These systems showed an exchangebias 

effect enhanced by 20%. High resolution MFM revealed a more homogenous pattern 

of UCS with a correspondingly higher density. The evolution of the F-domains in an 

applied field was strikingly different. 

Figure 1: . (A) UCS density calculated from measured MFM data and the instrument calibration 

function. Positive UCS (i.e. parallel to the cooling field) are colored yellow, negative UCS red. 

(B) UCS with overlayed contours of the F domains at H = 0; (C) Idem for H = 200mT. With few 

exceptions (such as pointed out by the arrows) the UCS align antiparallel to the domain 

magnetization at H=0. 

[1] I. Schmid, P. Kappenberger, O. Hellwig, M. Carey, E. Fullerton and H. J. Hug, EPL 81 (2008) 17001 

[2] I. Schmid, M. Marioni et al. submitted. 

163

Author 

Index 

164

Abe M. 51,58,92,141 Clerk A. A. 78 

Adachi H. 141 Cockins L. 78 

Ahn C. 109 Cuberes M. T. 125 

Albers B. J. 62 Dalvit D. 33 

Albonetti C. 69 Dalvit D. A. R. 43 

Altman E. I. 62,150 Danza, R. 76 

Amijs C. H. 130 de Boer M. P. 35 

Andrews K. M. 111 de Hosson J. Th. M. 42 

Annibale P. 137 de Man S. 39 

Aoki H. 129 Debierre J. M. 68 

Arai T. 94,114,118 Dede M. 162 

Asakawa H. 46,147 DelRio F. W. 35 

Ashino M. 64 Deresmes D. 105,106 

Atalan H. 162 Diesinger H. 105,106 

Baddorf A. P. 116,159 Dietz C. 89 

Bahr S. 153 Ding X. D. 103 

Balke N. 116,158 Duden T. 131 

Bao Y. 41 Ebeling D. 49 

Baratoff A. 54,74,75,95,96,130 Ebner A. 137 

Baykara M. Z. 62,150 Echavarren A. M. 130 

Bechstein R. 60,66,148,154 Elias G. 104 

Bennett S. D. 78 Eng L. M. 55,86,102,136,160 

Berber S. 64 Esquivel-Sirvent R. 32 

Besenbacher F. 151,152 Falter J. 109.112 

Bettac A. 80 Fan T. 161 

Binns C. 40 Feltz A. 80 

Biscarini F. 69,137 Ferrini G. 97 

Boag A. 104 Foster A. 100 

Bocquet F. 68,100 Fremy S. 67 

Borowik L. 106 French R. H. 29 

Braun D. A. 73,112 Freund H. J. 57 

Brugger T. 101 Fuchs H. 49,73,112 

Campbellova A. 71 Fukui K. 90 

Canetta C. 99 Fukuma T. 45,46,115,147 

Capaccioli S. 157 Gangopadhyay, S. 76 

Cavero-Pelaez, I. 31 Garcia R. 69,89,126,137 

Celik U. 162 Gepraegs S. 160 

Chan H. B. 41 Giessibl F. J. 72,77 

Chawla G. 119 Gimzewski J. K. 146 

Chen L. Q. 158 Glatzel Th. 54,74,75,95,96,101,104,127,130 

Chen, G. 38 Goennenwein S. T. B. 160 

Chevrier J. 37 Gomez C. J. 69 

Ching W. Y. 29 Gonzalez C. 59 

Cho Y. 155,156 Gottlieb O. 121 

Choi B. Y. 131 Grafstroem S. 86 

Choudhury S. 158 Graham N. 30 

Chu Y. H. 158 Greffet J-J. 37 

Cirelli R. A. 41 Gross L. 77,127 

165

Gross R. 160 Kitta M. 60,154 

Grutter P. 78 Kiyohara K. 94 

Gu N. 38,99 Klapetek P. 71 

Hane F. 102 Klemens F. 41 

Harada M. 48 Klocke M. 123 

Haubner K. 136 Kobayashi D. 87 

Heeck K. 39 Kobayashi K. 47,84,85,88,118,122,140,141 

Heinrich A. J. 72 Kobayashi N. 143 

Helm M. 86 Kobayashi S. 156 

Herruzo E. T. 89 Koch S. 54,74,75,95,96,101,127,130 

Heyde M. 57 Kokawa R. 118,141,145 

Hinterdorfer P. 137 Köhler D. 136,160 

Hirade M. 118 König T. 57 

Hirata Y. 88 Kusiaku K. 106 

Hosokawa Y. 84 Kurachi S. 144 

Hoffman J. E. 110 Kuroda M. 145 

Hoffman P. M. 98 Kushida S. 94 

Hoffman R. 55 Kühnle A. 60,66,133,134,148,153,154 

Hofmann T. 72 Labardi M. 157 

Hori K. 114 Laemmle K. 67 

Hornstein S. 121 Lamoreaux S. K. 43 

Hölscher H. 49,55,112 Lange M. 113 

Hug H. J. 163 Langer M. 101 

Huston S. M. 111 Langewisch G. 73 

Iannuzzi D. 39 Lau M. W. 135 

Ido S. 47,88 Lauritsen J. V. 151,152 

Imai T. 47 Leonenko Z. 102 

Inoue T. 141 Li Y. 82,120 

Itaya K. 129 Li Y. J. 52,143,144,149 

Jacob R. 86 Liebmann M. 109 

Jaehne E. 136 Liljeroth P. 77 

Jelinek P. 59,63,71 Liu Y. 135 

Jensen M. C. R. 151 Lobo-Checa J. 101 

Jeong Y. 118,142 Loppacher Ch. 68,100,160 

Jesse S. 116,117,158,159 Losilla N. S. 137 

Joshi N. 163 Loske F. 133 

Kageshima M. 52,82,120,143,144,149 Lozano J. R. 89 

Kalinin S. V. 116,117,158,159 Lucchesi M. 157 

Karci O. 162 Lutz C. P. 72 

Kawai S. 54,74,75,95,96,101,127,130 Lux-Steiner M. Ch. 61 

Kawai T. 138 Ma Z. 82,120 

Kawakatsu H. 87 Maass P. 133 

Khlobystov A. N. 64 Maeda Y. 138 

Kim J. 110 Maksymovych P. 116,158,159 

Kim W. J. 43 Malegori G. 97 

Kimura K. 47 Mansfield W. M. 41 

Kin N. 155 Marioni M. A. 163 

Kinoshita Y. 52,149 Martinez J. 126 

166

Martinez N. F. 69 Parashar P. 31 

Martinez R. V. 126 Parsegian A. 29,53 

Masago A. 93 Pawlak R. 68 

Matsamura H. 141 Pearl T. P. 111 

Matsumoto T. 138 Perez R. 59,65,69,71 

Matsushige K. 84,85,88,122,140 Pieper H. H. 153 

Melin T. 105,106 Pilet N. 62,109,163 

Mendoza P. 130 Podgornik R. 29 

Meyer E. 54,74,75,95,96,101,104,127,130 Poole P. 78 

Meyer G. 77,127 Port R. T. 111 

Milde P. 55,136,160 Porte L. 68 

Miller C. 139 Pou P. 65,71 

Milton K. A. 31 Pratama A. 58 

Minato T. 129 Preiner J. 137 

Mitani Y. 115 Prevosto D. 157 

Miyahara Y. 78 Prosenc M. 67 

Morita S. 51,58,92,141 Rahe P. 134,148 

Mohn F. 77 Rajter R. 29,34 

Moores B. 102 Ramesh R. 158,159 

Mori Y. 141 Rasmussen M. K. 152 

Moriarty P. 76 Rasool H. I. 146 

Morita K. 51,92 Reichling M. 66,151,153 

Möller R. 113 Repp J. 77 

Murai R. 141 Ribbeck H.-G. 86 

Murakami S. 141 Roca i Cabarrocas P. 106 

Nagashima K. 141 Rohlfing M. 66 

Naitoh Y. 52,82,120,143,144,149 Rolla P. A. 157 

Narayanaswami A. 99,38 Romer S. 163 

Nguyen-Tran T. 106 Rosenwalks Y. 104 

Nie H. Y. 135 Rousseau E. 37 

Nikiforov M. 117 Rozsival V. 63 

Nimmrich M. 134 Rychen J. 83 

Nishida S. 87 Sachrajda A. 78 

Nony L. 68,100 Sadewasser S. 61 

Nys J-P. 105 Salmeron M. 131 

Oesterhelt F. 49 Sasahara A. 118,142 

Ogawa T. 144 Sassi M. 68 

Ohta M. 141,145 Sato T. 94 

Oison V. 68 Satoh T. 149 

Okabe N. 87 Sawada D. 51,92 

Ondracek M. 63 Schaff O. 83 

Onishi H. 60,154 Schaffert J. 113 

Oral A. 162 Schirmeisen A. 50,73,112 

Ovchinnikov O. 116,117 Schlittler R. R. 127 

Oyabu N. 47,88,118,140,141 Schneider S. C. 86 

Ozer S. 163 Schütte J. 60,66,133,134,148,154 

Pai C. S. 41 Schwarz A. 67 

Palasantzas G. 42 Schwarz U. D. 62,109,112,150 

167

Schwendemann T. C. 62,150 Wagner T. 129 

Shajesh K. V. 31 Weiner D. 50,73 

Sharma S. 146 Welker J. 72 

Shavit A. 121 Wenzel M. T. 86 

Shen S. 38 Wiesendanger R. 64,67 

Shi Y. 131 Wijngaarden R. J. 39 

Shluger A. 79,132 Williamson R. 139 

Siber A. 29 Winnerl S. 86 

Simon G. H. 57 Wintjes N. 113 

Siria A. 37 Wojciech K. 69 

Solares S. D. 119 Wolf D. E. 123 

Someya T. 145 Wright C. A. 119 

Staffier P. 109 Wu W. 121 

Stara I. G. 134 Xu J. B. 103 

Studenikin S. A. 78 Yabuno H. 145 

Such B. 73,74,75,95,96,101,130 Yamada H. 47,84,85,88,118,122,140,141 

Sugawara Y. 82,120,143,144,149 Yamatani H. 118 

Sugimoto Y. 51,58,92 Yang D. Q. 135 

Sushkov A. 43 Yang J. 135 

Sutter P. 108 Yokota Y. 90 

Suzuki K. 47,140 Yu P. 159 

Svetovoy V. B. 42 Yurtsever A. 58 

Sweetman A. 76 Zahl P. 107,108 

Tagami K. 48 Zech M. 110 

Takahashi K. 143 Zerweck U. 55,86,136,160 

Takano K. 141 Zhang J. X. 103 

Tang H. X. 36 Zou J. 41 

Ternes M. 72 Zypman F. 124 

Theron D. 106 

Thornton S. 40 

Tomanek D. 64 

Tomitori M. 94,114,118,142 

Torbruegge S. 83,153 

Torricelli G. 40 

Trevethan T. 79,132 

Troeger L. 148 

Tsifrinovich V. I. 161 

Tsukada M. 48,88,93 

Tsunemi E. 85 

Ueda Y. 45,46 

Umeda K. 90 

van Zwol P. J. 42 

Venkataramani K. 151,153 

Wagner J. 31 

168

List of 

Participants 

169

LastName FirstName Institution Email 

Altman Eric Yale University eric.altman@yale.edu 

Arai Toyoko Kanazawa University arai@staff.kanazawa-u.ac.jp 

Asakawa Hitoshi Kanazawa University hi_asa@staff.kanazawa-u.ac.jp 

Baratoff Alexis University of Basel alexis.baratoff@unibas.ch 

Baykara Mehmet Yale University mehmet.baykara@yale.edu 

Bechstein Ralf Aarhus University ralf@inano.dk 

Bernard Laetitia EMPA laetitia.bernard@empa.ch 

Bettac Andreas Omicon NanoTechnology a.bettac@omicron.de 

Borowik Lukasz Institut d'Electronique 

Microelectronique Nanotechnologie 

lbor@tlen.pl 

Braendlin Dominik Nanosurf AG braendlin@nanosurf.com 

Cannara Rachel National Institute of Standard and 

Technology 

rachel.cannara@nist.gov 

Celik Umit Istanbul Technical University umitcelik@itu.edu.tr 

Chan Ho Bun University of Florida hochan@phys.ufl.edu 

Chawla Gaurav University of Maryland College Park gchawla@umd.edu 

Cho Yasuo Tohoku University yasuocho@riec.tohoku.ac.jp 

Dalvit Diego LANL dalvit@lanl.gov 

de Boer Maarten Sandia National Labs mpdebo@sandia.gov 

de Man Sven VU University Amsterdam sdeman@nat.vu.nl 

Diesinger Heinrich Institut Elelectronique 

Microelectronique Nanotechnologie 

170 

heinrich.diesinger@isen.iemn.univlille1.fr 

Ding Xidong Sun Yat-sen University dingxd@mailsysu.edu.cn 

Ebeling Daniel University of Muenster Daniel.Ebeling@uni-muenster.de 

Esquivel-Sirvent Raul Universidad Nacional Autonoma de 

Mexico 

raul@fisica.unam.mx 

Faddis David Nanosurf Inc. faddis@nanosurf.com 

Falter Jens Westfallische Wilhelms-Universitaet 

Muenster 

JensFalter@Uni-Muenster.de 

Ferrini Gabriele University Cattolica gabriele@dmf.unicatt.it 

Fukui Ken-ichi Osaka University kfukui@chem.es.osaka-u.ac.jp 

Fukuma Takeshi Kanazawa University fukuma@staff.kanazawa-u.ac.jp 

Giessibl Franz University of Regensburg franz.giessibl@physik.uni-r.de 

Glatzel Thilo University of Basel Thilo.Glatzel@unibas.ch 

Gomez Carlos IMM - CSIC carlos@imm.cnm.csic.es 

Graham Noah Middlebury College ngraham@middlebury.edu 

Gross Leo IBM Research lgr@zurich.ibm.com 

Grutter Peter McGil University grutter@physics.mcgill.ca 

Hafizovic Sadik Zurich Instruments sadik.hafizovic@zhinst.com 

Heer Flavio Zurich Instruments flavio.heer@zhinst.com 

Heyde Markus Fritz-Haber-Institute of the Max- 

Planck-Society 

heyde@fhi-berlin.mpg.de 

Hoffmann Peter Wayne State University hoffmann@wayne.edu 

Hori Kenichirou Kanazawa University horiken@stu.kanazawa-u.ac.jp 

Hosokawa Yoshihiro Kyoto University hosokawa@piezo.kuee.kyoto-u.ac.jp 

Hölscher Hendrik Forschungszentrum Karlsruhe hendrik.hoelscher@imt.fzk.de 

Huston Shawn North Carolina State University smhuston@ncsu.edu

Ido Shinichiro Kyoto University ido@piezo.kuee.kyoto-u.ac.jp 

Jelinek Pavel Institute of Physics of the ACSR, 

v.v.i. 

jelinekp@fzu.cz 

Jesse Stephen Oak Ridge National Laboratory sjesse@ornl.gov 

Jhe Wonho Seoul National University whjhe@snu.ac.kr 

Kawai Shigeki University of Basel shigeki.kawai@unibas.ch 

Kim Woo-Joong Yale University Woo-Joong.Kim@yale.edu 

Kim Jeehoon Harvard University jeehoonkim@gmail.com 

Kin Nobuhiro Tohoku University kin@riec.tohoku.ac.jp 

Kinoshita Yukinori Graduate School of Engineering, 

Osaka Univ 

kinoshita@ap.eng.osaka-u.ac.jp 

Kiyohara Kosei Kanazawa University kosei@stu.kanazawa-u.ac.jp 

Klocke Michael University of Duisburg-Essen m.klocke@uni-duisburg.de 

Kobayashi Kei Kyoto University keicoba@iic.kyoto-u.ac.jp 

Kobayashi Shin-ichiro Research Institute of Electrical 

Communication 

kshin@atom.che.tohoku.ac.jp 

Koch Sascha University of Basel sascha.koch@unibas.ch 

Kose Rickmer SPECS USA Corp. rkose@specsus.com 

Kuroda Masaharu National Institute of Advanced 

Industrial Science and Technology 

(AIST) 

m-kuroda@aist.go.jp 

Kühnle Angelika University of Osnabrueck kuehnle@uos.de 

Labardi Massimiliano CNR-INFM labardi@df.unipi.it 

Lamoreaux Steve Yale University steve.lamoreaux@yale.edu 

Lange Manfred University of Duisburg-Essen manfred.lange@stud.uni-due.de 

Langewisch Gernot University of Muenster g.langewisch@uni-muenster.de 

Lengel George SPECS USA Corp. lengel@nanonis.com 

Li Yanjun Osaka Univarsity liyanjun@ap.eng.osaka-u.ac.jp 

Loppacher Christian Aix Marseille University Christian.Loppacher@im2np.fr 

Loske Felix University of Osnabrueck floske@uos.de 

Maksymovych Petro Oak Ridge National Laboratory maksymovychp@ornl.gov 

Masago Akira Tohoku University masago@wpi-aimr.tohoku.ac.jp 

Mavrokefalos Anastassios Massachusetts Institute of 

Technology 

anastass@mit.edu 

Milde Peter TU Dresden peter.milde@iapp.de 

Milton Kimball University of Oklahoma milton@nhn.ou.edu 

Minato Taketoshi International Advanced Research 

and Education Organization 

minato@atom.che.tohoku.ac.jp 

Miyahara Yoichi McGill University miyahara@physics.mcgill.ca 

Moenig Harry Yale University harry.moenig@yale.edu 

Moon Christopher Agilent Laboratories chris_moon@agilent.com 

Moores Brad University of Waterloo brad.moores@gmail.com 

Moriarty Philip University of Nottingham philip.moriarty@nottingham.ac.uk 

Morita Seizo Osaka University smorita@eei.eng.osaka-u.ac.jp 

Möller Rolf University of Duisburg-Essen rolf.b.moeller@uni-due.de 

Nagashima Ken Osaka University nagasima@eei.eng.osaka-u.ac.jp 

Naitoh Yoshitaka Osaka University naitoh@ap.eng.osaka-u.ac.jp 

Narayanaswamy Arvind Columbia University arvind.narayanaswamy@columbia.edu 

171

Nishida Shuhei Institute of Industrial Science, 

University of Tokyo 

snishida@iis.u-tokyo.ac.jp 

Onishi Hiroshi Kobe University oni@kobe-u.ac.jp 

Oral Ahmet Sabanci University aoral@sabanciuniv.edu 

Oyabu Noriaki Kyoto University oyabu@piezo.kuee.kyoto-u.ac.jp 

Palasantzas Georgios University of Groningen g.palasantzas@rug.nl 

Parsegian Adrian NIH parsegia@mail.nih.gov 

Perez Ruben Universidad Autonoma de Madrid ruben.perez@uam.es 

Pieper Hans Hermann University of Osnabrueck hapieper@uos.de 

Pilet Nicolas EMPA nicolas.pilet@empa.ch 

Podgornik Rudolf NIH podgornr@mail.nih.gov 

Porthun Steffen RHK Technology, Inc porthun@rhk-tech.com 

Rahe Philipp University of Osnabrueck prahe@uos.de 

Rasmussen Morten Aarhus University mkr@inano.dk 

Rasool Haider UCLA haider@chem.ucla.edu 

Reichling Michael University of Osnabrueck reichling@uos.de 

Sadewasser Sascha Helmholtz Zentrum Berlin sadewasser@helmholtz-berlin.de 

Sasahara Akira Japan Advanced Institute of Science 

and Technology 

sasahara@jaist.ac.jp 

Sawada Daisuke Graduate School of Engineering, 

Osaka University 

d-sawada@afm.eei.eng.osaka-u.ac.jp 

Schirmeisen Andre University of Muenster schirmeisen@uni-muenster.de 

Schütte Jens University of Osnabrueck jens.schuette@uos.de 

Schwarz Udo Yale University udo.schwarz@yale.edu 

Schwarz Alexander University of Hamburg aschwarz@physnet.uni-hamburg.de 

Schwendemann Todd Yale University todd.schwendemann@yale.edu 

Shen Sheng MIT sshen1@mit.edu 

Siria Alessandro CNRS alessandro.siria@grenoble.cnrs.fr 

Staffier Peter Yale University peter.staffier@yale.edu 

Sugawara Yasuhiro Osaka University sugawara@ap.eng.osaka-u.ac.jp 

Sugimoto Yoshiaki Graduate School of Engineering ysugimoto@afm.eei.eng.osaka-u.ac.jp 

Sushkov Alexander Yale University alex.sushkov@yale.edu 

Suzuki Kazuhiro Kyoto University suzuki@piezo.kuee.kyoto-u.ac.jp 

Sweetman Adam University of Nottingham ppxams@nottingham.ac.uk 

Tang Hong Yale University hong.tang@yale.edu 

Tomas Herruzo Elena IMM-CSIC elena.tomas@imm.cnm.csic.es 

Tomitori Masahiko Japan Advanced Institute of Science 

and Technology 

tomitori@jaist.ac.jp 

Torricelli Gauthier University of Leicester gt47@le.ac.uk 

Trevethan Thomas University College London t.trevethan@ucl.ac.uk 

Tsukada Masaru Tohoku University tsukada@wpi-aimr.tohoku.ac.jp 

Tsunemi Eika Kyoto University eika@piezo.kuee.kyoto-u.ac.jp 

van Zwol Peter Groningen petervanzwol@gmail.com 

Venkataramani Krithika Aarhus University krithika@inano.dk 

Werle Christoph University of Basel christop.werle@unibas.ch 

Williamson Ryan Saint Louis University williamson.ryan@gmail.com 

Wintjes Nikolai University of Duisburg-Essen nikolai.wintjes@uni-due.de 

Workman Richard Agilent Laboratories richard_workman@agilent.com 

172

Wright Alan University of Maryland College Park cawright@umd.edu 

Yurtsever Ayhan Osaka University ayhan@afm.eei.eng.osaka-u.ac.jp 

Zahl Percy Brookhaven National Laboratory pzahl@bnl.gov 

Zerweck Ulrich University of Technology Dresden ulrich.zerweck@iapp.de 

173

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attocube systems’ products. 

For further technical information concerning attocube systems’ products, please visit the website 

www.attocube.com.

Nanosurf ® Saphyr 

Your Ultimate “Laboratory-in-a-Box” Signal Analyzer/Controller 

The Nanosurf Saphyr is a completely modular digital signal-processing unit that can be used 

as an SPM sensor controller for a wide range of applications. Its signal modules can be set to 

work independently or to use their analysis power on the same microscopy signals. High-end 

analog preconditioning stages and digital inter-module communication provide an as of yet 

unseen usable signal range. Controlled by an easy-to-use software interface, the Saphyr is your 

all-in-one signal-processing solution. 

Go beyond the limits of your current measurement capabilities: 

• Generate sub-Angstrom amplitudes with the Saphyr PLL Modules and SignalCompensator 

• Detect even the smallest forces with the KPFM Controller Module and SignalSuppressor 

• Track harmonic frequencies with up to four PLL or Lock-In Modules and SignalSync 

• Unify control over multiple cantilevers or scan heads in a single powerful system 

Get the most out of your investment: 

• Combine the Saphyr with any home-built or commercial scan controller and scan head 

• Immediately update system characteristics and features through a simple file download 

• Extend your system’s capabilities with cost-effective modules to match your growing needs 

www.nanosurf.com/saphyr

AD VT-QPlus_ONUS / 09-May 

Nanotechnology is our Profession! 

Z 

dF 

D 

The Si(111) 7x7 surface with 

QPlus 

Beam 

AFM in an Omicron VT at RT 

Deflection AFM 

(raw data). 

with QPlus! 

- Expanding the capabilities of your Omicron VT 

- Ideal sensor for the detection of short range forces 

- QPlus replaces needle sensor technology 

- Provides 2 orders of magnitude better force sensitivity 

Height [pm] 

30 

20 

10 

0 

-10 

0.5 

1 1.5 2 2.5 3 

Position [nm] 

Imaging of rest atoms (raw data) of the Si(111) 7x7 surface with QPlus AFM in an Omicron 

VT at 50 K (Left image). Line profile showing the height difference of the rest atoms (above). 

Measurement: A. Bettac, Omicron NanoTechnology 

Z 

dF 

Germany: Omicron NanoTechnology GmbH 

Tel: +49(0) 6128 / 987 - 0 

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Tel: 952 345 5240 

e-mail: info@omicronUS.com 

D 

The Si(111) 7x7 surface with 

QPlus AFM in an Omicron VT at RT 

(raw data).

Imaging the Future of Nanoscience 

World leading technology in UHV Scanning Probe Microscopes, SPM Control Systems, and 

Complete Surface Analysis Systems. RHK Technology sets the standard for powerful, flexible 

solutions for researchers pushing the limits of fundamental science at the atomic scale 

PLLPro 2 AFM Control System 

RHK’s next generation of AFM control. 

Ultra high performance and KFM capability in a one box solution. 

IDEAL INTERFACE IHDL TM 

RHK’s unique Iconic Hardware Description Language unites 

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Air-Cleaved Mica NC-AFM 

Large regularly shaped islands on air-cleaved mica surfaces after 

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Kolodziej, M. Reichling 

Tuning Fork AFM on Silicon 

RHK UHV 325 with RHK SPM 1000 and PLLPro Controllers. 

True constant height image with current and ∆F(Hz) acquisition 

amplitude of oscillation, 3Å peak to peak. S. Pryadkin, RHK. 

RHK Technology, Inc. | 1050 East Maple, Troy, MI 48083 | 248.577.5426 | www.rhk-tech.com | Visit our booth at NC-AFM 2009

Surface Analysis 

Technology 

Aarhus STM 

State-of-the-Art STM Technology 

for Advanced SPM Research 

Key Features: 

� Quartz oscillator based design: sensor (tungsten tip) 

separated from oscillator: force and tunneling 

signals simultaneously and indepentently 

� Imaging of conductive and non-conductive samples 

in non-contact mode 

Vacuum 

Components 

� Atomically resolved imaging on a daily basis 

JT-STM 

Ultra-low temperature Joule Thomson-STM 

for ultimate STM spectroscopy and manipulation 

Key Features: 

� Designed at Aarhus University, group of 

Prof. F. Besenbacher 

� Extreme stability 

� Highest productivity 

� Variable temperature: 115 K to 400 K 

(for STM optional: 1300 K) 

� One-tip-suits-all: in situ tip sputtering 

Key Features: 

� Cryostat designed by Prof. W. Wulfhekel 

� Base temperature: < 1 K (optional < 500 mK) 

� LHe hold time: > 4 days 

� NANONIS control package 

� Magnetic field up to 3 Tesla 

Applications: 

Surface Analysis 

System Software 

AFM Option 

Combining KolibriSensor TM and 

NANONIS Control Package 

� Inelastic electron tunneling spectroscopy 

� Investigation of superconductors 

� Quantum structures 

� Spin polarized tunneling 

� Atomic manipulation 

� Molecular electronics 

Computer 

Technology

First Announcement: 

13th International Conference on 

Noncontact Atomic Force Microscopy 

Kanazawa, Japan 

13th International Conference on 

Noncontact Atomic Force Microscopy (ncAFM2010) 

and 

Satellite Workshops on 

bio-imaging, 

solid-liquid interface, 

SPM standardization 

Venue: 

Ishikawa Ongakudo, Kanazawa, JAPAN 

Date: 

July 31 - August 1, 2010 (Satellite Workshops) 

August 2 - 5, 2010 (ncAFM2010) 

Conference Chair: 

Toyoko Arai (Kanazawa Univ.) 

Program committee: 

Masayuki Abe (Osaka Univ.) 

Proceedings committee: 

Satoshi Watanabe (Univ. of Tokyo) 

Web page: 

http://www.afm.eei.eng.osaka-u.ac.jp/ncafm2010/ 

Kanazawa information: 

http://www.kanazawa-tourism.com/ 

Co-organizers (tentative): 

167th Committee on Nano-Probe Technology of JSPS 

The Surface Science Society of Japan 

Osaka University Global Center of Excellence Program 

Center for Electronic Device Innovation

Notes

Program Summary of the NC-AFM 2009 Satellite Workshop on 

Casimir Forces and Their Measurement 

Monday sessions only; Tuesday sessions are joint with the NC-AFM Conference (see the main 

conference program for listing). Note in particular that the Casimir workshop’s second invited talk, 

given by Adrian Parsegian (NIH, USA), will take place Tuesday 14:30-15:10. 


7:45 Registration 


9:00 Rudi Porgornik (University of Ljubljana, Slovenia), invited 

9:30 Noah Graham (Middlebury College, USA) 

9:55 Kimball Milton (University Oklahoma, USA) 

10:20 


10:50 Raul Esquivel-Sirvent (Universidad Nacional Autónoma, Mexico) 

11:15 Diego Dalvit (Los Alamos National Laboratory, USA) 

11:40 Rick Rajter (MIT, USA) 

12:05 Maarten de Boer (Sandia National Laboratory, USA) 

12:30 

Lunch (12:30-14:30) 

14:30 Hong Tang (Yale University, USA) 

14:55 Alessandro Siria (CNRS, France) 

15:20 Arvind Narayanaswamy (Columbia University, USA) 

15:45 


16:15 Sven de Man (VU University Amsterdam, Netherlands) 

16:40 Gauthier Torricelli (University of Leicester, UK) 

17:05 Ho Bun Chan (University of Florida, USA) 

17:30 Peter van Zwol (University of Groningen, Netherlands) 

17:55 Woo-Joong Kim (Yale University, USA) 

18:30-20:30 

Welcome Reception with Dinner

NC-AFM 2009 

Sessions 

Monday 

August 10 

�� Liquids I 

Tuesday 9:20-10:40 

�� Force Spectroscopy I 

Tuesday 11:20-12:40 

�� Electronic, photonic, & Casimir forces 

Tuesday 14:30-15:50 

�� Oxides 


�� Carbon-based materials 


Tuesday 

August 11 

Wednesday 

August 12 

�� Molecules on insulators 


�� Force spectroscopy II 

Thursday 9:00-10:40 

�� Forces & charges 

Thursday 11:20-13:00 

�� Method development 

Friday 9:00-10:40 

�� Liquids II 

Friday 11:20-12:40 

Thursday 

August 13 

Friday 

August 14 

8:30 Registration Registration Registration Registration 

9:00 Opening Remarks M. Heyde A. Campbellova Y. Naitoh 

9:20 T. Fukuma A. Yurtsever F. J. Giessibl S. Torbrügge 

9:40 H. Asakawa R. Pérez G. Langewisch Y. Hosokawa 

10:00 N. Oyabu R. Bechstein A. Baratoff E. Tsunemi 

10:20 M. Tsukada S. Sadewasser S. Kawai U. Zerweck 

10:40 Coffee Break Coffee Break Coffee Break Coffee Break 

11:20 D. Ebeling U. D. Schwarz A. Sweetman S. Nishida 

11:40 A. Schirmeisen P. Jelínek L. Gross S. Ido 

12:00 Y. Sugimoto M. Ashino Y. Miyahara E. T. Herruzo 

12:20 Y. Sugawara P. Pou T. Trevethan K. Fukui 

12:40 A. Bettac Closing Remarks 

13:00 

Lunch 

110 min. 

(12:40-14:30) 

Lunch 

110 min. 

(12:40-14:30) 

14:30 

A. Parsegian 

A. Kühnle 

14:50 

(invited) 

A. Schwarz 

15:10 Th. Glatzel Ch. Loppacher 

15:30 H. Hölscher C. J. Gómez 

15:50 

| 

18:00 

C 

A 

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M 

I 

R 

W 

O 

R 

K 

S 

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O 

P 

18:30-20:30 

Welcome 

Reception/Dinner 

Poster Session I Poster Session II 

Lunch 

90 min. 

(13:00-14:30) 

18:30-22:00 

Conference 

Banquet

Noncontact Atomic Force Microscopy - Yale School of Engineering ...

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