Local polarization dynamics in ferroelectric materials

Rep. Prog. Phys. 73 (2010) 056502
S V Kalinin et al
I
V (air)
I. No switching
II. Partial III. Uniform
(a)
1 µm
IV (isopropanol)
(b)
400 nm
III (isopropanol)
Field localization
non-local non-local
IV. Fractal
V. Local
3 µm
2 µm
(e)
Pulse bias and length
Figure 61. (a)–(d) PFM phase images illustrating domain morphology in regions I–V and the choice of solvent for the phase map
in (e). (e) Schematic parameter diagram of possible switching modes versus field localization and pulse parameters. Reproduced
from [413]. Copyright 2007, American Physical Society.
Figure 62. Fabrication steps for insulated PFM probe for imaging in liquid environment. Reproduced from [414]. Copyright 2007,
American Institute of Physics.
switched regions [269] and may be of concern to bismuth
ferrite capacitor based applications.
7. Summary
Strong coupling between order parameters and electromechanical
response in ferroelectric materials enables a local probe
approach for studying the static domain structures and polarization
dynamics. The unique image formation mechanism of
PFM and its spectroscopic and dynamic modes have rendered
them a quantitative and powerful method for probing ferroelectrics
on the nanometer level, and have opened new venues
in understanding the role of defects on switching, polarization
ordering in relaxors and many other applications. The future
will undoubtedly see atomic level studies on an engineered
defect structure (including imaging in vacuum and in liquid),
perhaps on a single unit cell level. A new generation of dynamic
PFM modes is emerging to allow high energy resolution
spectroscopy and of weakly piezoelectric materials. The combination
of PFM and EM methods offers the opportunity for
imaging atomic rearrangements during polarization switching
in situ. These developments will lead to new advancements in
areas such as information technologies, data storage, energy
technologies, electrophysiology, as well as new serendipitous
areas we can only imagine.
Acknowledgments
This work was sponsored by the Center for Nanophase
Materials Sciences, Oak Ridge National Laboratory, managed
and operated by UT-Battelle, LLC for the Office of Basic
Energy Sciences, US Department of Energy (SVK, BJR)
and by the DOE under the grant number DOE DE-FG02-
07ER46417 (LQC). BJR also acknowledges the support of
UCD Research. The authors are grateful to E A Eliseev and
S Choudhury for their contributions to this work and to the
numerous authors who provided permission to reproduce their
work here. SVK gratefully acknowledges the collaboration
with Stephen Jesse, Nina Balke, Maxim Nikiforov, Katyayani
Seal, Peter Maksymovych and Alexander Tselev, as well as
Roger Proksch (Asylum Research). He is also grateful to
numerous CNMS users and attendees of the PFM workshop
series, discussions with whom have contributed immensely to
the writing of this paper.
References
[1] von Hippel A, Breckenridge R G, Chesley F G and Tisza L
1946 J. Ind. Eng. Chem. 38 1097
[2] Wul B M 1946 J. Phys. USSR 10 95
Wul B M 1946 Nature 157 808
61