Multiscale kinetic model for polarization switching in ferroelectric polymer thin films

作     者：Rajeev Ahluwalia Michael B. Sullivan David J. Srolovitz Jian Wei Zheng Alfred C. H. Huan 

作者机构：Materials Theory and Simulation Laboratory Institute of High Performance Computing A*STAR (Agency for Science Technology and Research) Singapore 117528 Singapore Institute of Materials Research and Engineering A*STAR (Agency for Science Technology and Research) Singapore 117602 Singapore Computational Materials Science and Engineering Programme Institute of High Performance Computing A*STAR (Agency for Science Technology and Research) Singapore 117528 Singapore Department of Physics Yeshiva University New York New York 10033 USA Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637616 Singapore 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2008年第78卷第5期

页      面：054110-054110页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

摘      要：Polarization switching in ferroelectric polymers is studied using a multiscale framework. A continuum Landau-Ginzburg-Devonshire model for a first-order phase transition is parametrized for ideal all trans chains of P(VDF-TrFE) (70:30) copolymers using data obtained from molecular-dynamics (MD) simulations. Thermal fluctuations and kinetics are accounted for by using a time-dependent Ginzburg-Landau model where the length and time scales, as well as the thermal noise amplitude, are also set from MD simulations. This method is used to investigate the nature of polarization switching in ferroelectric polymers and to test recent claims that ultrathin ferroelectric polymer films undergo intrinsic switching. Our simulations show that for a defect-free system, domain nucleation due to thermal fluctuations prevents homogeneous switching of the polarization, even at very small thicknesses. However, this nucleation does not substantially decrease the coercive field compared to the intrinsic value.