ICMCTF 2012! - CD-Lab Application Oriented Coating Development

Post Deadline Discoveries and Innovations
Room: Pacific Salon 1-2 - Session PD-1
Post Deadline Discoveries and Innovations
Moderator: W. Kalss, OC Oerlikon Balzers AG,
Liechtenstein, S. Ulrich, Karlsruhe Institute of Technology,
Germany
1:30pm PD-1-1 The Multi Beam Sputtering: a new thin film deposition
approach, P. Sortais (sortais@lpsc.in2p3.fr), T. Lamy, J. Médard,
Laboratoire de Physique Subatomique et Cosmologie de Grenoble (LPSC),
France
Thanks to the latest development of ultra compact and reliable microwave
ion sources 1,2 it is now possible to build an ion beam sputterring system
composed of an arbitrary large number of simple ion sources that can be
individually tuned. With this new concept of Multi Beam Sputtering (MBS)
device, new possibilities are conceivable for the Ion Beam Sputtering (IBS)
technology 3,4 , especially for thin film deposition on large size substrates
with high uniformity. With MBS, the deposition profile is not defined by
the shape and the tuning of a unique large beam, but by the sum of the
contributions of a great number of small, well controlled in size, sputterring
spots. The uniformity is the consequence of the geometric sum of all
sputterring lobes obtained by each sputtering spot. The ion sources units can
be distributed along a circle or a line and each ion beam delivered by an ion
source impinges its own target. An individual source of a typical size 3x3x3
cm uses a few watts of microwave power for producing a beam up to 1 mA
with energy in the range of 5 to 15 keV. The first operational device, MBS-
20, uses 20 of such ion sources distributed on a circle around a 70 mm
diameter multi-target holder allowing thin film deposition on 100 to 300
mm diameter substrates with deposition rates in the range of 0 to 1 µm/h.
An important point, since each ion source uses an individual target, is that
co-evaporation of several components can be done simultaneously. By the
way, the deposition of alloys with a controlled stoechiometry is easier than
with any other method and without uniformity loss. We will show
preliminary results for Cu, Ta, Ta2O5, C, Si02, Ti, TiN, TiO2, TiAlN and Th
on 100 or 200 mm glass substrate diameters, Mylar 0.5 µm or Si substrates.
All these processes can be done with reactive atmosphere allowing oxide or
nitride deposition.
1
P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev.
Sci. Instrum. 81 (2010) 02B31
2
P. Sortais, T. Lamy, J. Médard, J. Angot, P. Sudraud et al., Rev. Sci.
Instrum. 83, 02B912 (2012
3
Patent pending N° 1150981.
4
Under Grant Grenoble Alpes Valorisation Innovation Technologies
(GRAVIT) 080606, may 2009.
1:50pm PD-1-2 Molecular dynamics simulation and experimental
validation of nanoindentation measurements of silicon carbide
coatings., A.-P. Prskalo (alen-pilip.prskalo@imwf.uni-stuttgart.de),
Universität Stuttgart, Germany, S. Ulrich, Karlsruhe Institute of
Technology, Germany, S. Schmauder, J. Lichtenberg, , C. Ziebert, Kit, Iam-
Awp, Germany
Molecular dynamics simulation of the nanoindentation was used to
investigate mechanical properties of single layer silicon carbide coatings on
silicon substrates. Indenter load-penetration depth relation was determined
and put into relation to the internal coating structure and the substrate
behavior. In order to reach this objective, an indenter tip in the form of a
Berkovich indenter was introduced, a discrete indenter motion of 0.2 Å was
imposed. For the modeling of the Si-C system, well known bond-order
Tersoff potential was used, while the substrate-indenter interaction was
modeled by a self-developed short range repulsive pair potential. From the
indenter load-penetration depth relation, mechanical values of hardness and
Young modulus for the coatings could be obtained. Hardness values
determined by molecular dynamics simulations were in the range between
26.4 GPa and 34.4 GPa. These results are in good agreement with
experimental measurements using UMIS 2000 system delivering values
between 20.1 GPa and 35 GPa in dependence of the micro structure of the
coating, the deposition temperature and maximum indentation depth.
2:10pm PD-1-3 Anatase TiO2 Beads Having Ultra-fast Electron
Diffusion Rates for use in Low Temperature Flexible Dye-sensitized
Solar Cells, J.-M. Ting (jting@mail.ncku.edu.tw), Ke, National Cheng
Kung University, Taiwan
The first use of mesoporous TiO2 beads in plastic substrate flexible dyesensitized
solar cell (FDSC) is demonstrated. Pure anatase TiO2 beads with
various sizes (250 to 750 nm) and characteristics are obtained using a
Thursday Afternoon, April 26, 2012 92
modified and efficient two-step method. The concept of chemical sintering,
eliminating the step of additive removal, is used to prepare bead-containing
paste for room temperature fabrication of photoanode having good adhesion
to the substrate. The obtained photoanodes are examined for their dye
loadings and light absorbance properties. Various plastic substrate FDSCs
having commercial P25- and bead-containing photoanodes are fabricated
and evaluated. The resulting cells are evaluated for the J-V characteristics,
electron diffusion time, electron lifetime, charge-collection efficiency,
electron-injection efficiency and incident photon-to-electron conversion
efficiency. The bead-only cells not only have better efficiencies, as high as
~5%, but also exhibit ultra-fast electron diffusion rates, less than 1 ms. The
best efficiency and electron diffusion rates are respectively 15% higher and
two-order of magnitude faster than the P25-only cell. The effects of the
bead characteristics on the cell performance is presented and discussed.
2:30pm PD-1-4 MOCVD nano-structured TiO2 coatings for corrosion
protection of stainless steels, H. Herrera-Hernández
(hhh@correo.azc.uam.mx), M. Palomar-Pardavé, Universidad Autónoma
Metropolitana- Azcapotzalco, Mexico, J.A. Galaviz-Pérez, J.R. Vargas-
García, Departamento de Ingeniería, Metalúrgica, ESIQIE-IPN, Mexico
TiO2 nanoparticles were deposited on 316 stainless steel substrates at three
different temperatures using a horizontal hot-wall reactor in the presence of
a titanium isopropoxide Ti(OC3H7)4 precursor, method known as metal
organic chemical vapor deposition (MOCVD). The influence of deposition
temperature (Tdep 300, 400 and 500 ºC) on the structural and protective
properties of the TiO2 nanoparticles was discussed. The morphology and
structure of these nanoparticles that form a continuous thin coating over the
steel was investigated by X-ray diffraction (XRD), energy dispersive
spectroscopy (EDS) and scanning electron microscopy (SEM) techniques.
The corrosion resistance of the TiO2 coatings was evaluated in a strong
corrosive solution (0.5M H2SO4) by means of electrochemical
measurements such as anodic polarization, cyclic voltammetry (CV) and
electrochemical impedance spectroscopy (EIS). Anodic polarization results
revealed that the pitting corrosion potential (Epit) shifted to a more positive
when the deposition temperature increased in comparison to the bare
substrate, while CV behaviour showed lower passive current density for
TiO2 coatings. Through the EIS data it was found that TiO2 nanoparticles
deposited at 500 ºC for 30 min did not corroded by pits during over
exposure for 100 days in such aggressive electrolyte. A higher electrical
coating resistance (RTiO2 = 59.52 KW-cm 2 ) and lower capacitance (CTiO2=
87.37 mF/cm 2 ) was measured for 500 ºC TiO2 coating in contrast to 300 or
400 ºC coatings.
The improve pitting corrosion resistance for TiO2 nanoparticles deposited at
500 ºC is attributed to its morphology features and its uniform & compact
anatase structure, which consisted of platelets agglomerates with very small
quasi-spherical nano-particles (10~nm) that impedes the free transfer of
electrons and mass-transport process across the coating. Therefore, stainless
steels surface modification with TiO2 nanoparticles showed excellent
corrosion resistance for long times exposure in sulphuric acid that makes it
an attractive material for biomedical applications.
2:50pm PD-1-5 Improvement on the mechanical and corrosion
properties of nanometric HfN/VN superlattices, P. Prieto, Excellence
Center for Novel Materials, CENM, Cali, Colombia, C.A. Escobar,
Universidad del Valle, Colombia, J.C. Caicedo, Universidad del Valle,
Colombia, W. Aperador, Universidad Militar Nueva Granada, Colombia, J.
Esteve, M.E. Gomez, Universitat de Barcelona, Spain
The aim of this work is the improvement of the mechanical and
electrochemical behavior of 4140 steel substrate using HfN/VN
multilayered system as a protective coating. We have grown HfN/VN
multilayered via reactive r.f. magnetron sputtering technique in which was
varied systematically the bilayer period (Λ), and the bilayer number (n),
maintaining constant the total thickness of the coatings (~1.2 μm). The
coatings were characterized by X-ray diffraction (XRD), X-ray photo
electron spectroscopy (XPS), electron microscopy assisted with selected
area electron diffraction. The mechanical properties were analyzed by
nanoindentation method. The electrochemical properties were studied by
Electrochemical Impedance Spectroscopy and Tafel curves. XRD results
showed a preferential growth in the face-centered cubic (111) crystal
structure for [HfN/VN]n multilayered coatings. The best improvement of
the mechanical behavior was obtained when the bilayer period (Λ) was 15
nm (n = 80), yielding the highest hardness (37 GPa) and elastic modulus
(351 GPa). The values for the hardness and elastic modulus are 1.48 and
1.32 times greater than the coating with n = 1, respectively. The
enhancement effects in multilayer coatings could be attributed to different
mechanisms for layer formation with nanometric thickness due to the Hall-
Petch effect. The maximum corrosion resistance was obtained for coating
with (Λ) equal to 15 nm, corresponding to n = 80 bilayered. The
polarization resistance and corrosion rate were around 112.19 kOhm cm 2
and 3.66x10 -3 mm/year, these values were 98 % and 99 % better than those