Computational Nanostructures and Physical Properties of the Ultra-Thin Ferroelectric Langmuir-Blodgett Films

Abstract

Computational molecular nanostructures and transition physical properties of the ultra-thin ferroelectric (FE) Langmuir-Blodgett (LB) films, based on polymer poly(vinylidene fluoride) PVDF and its copolymers with trifluoroethylene TrFE (CH₂-CF₂:CHF-CF₂) were explored theoretically using ab initio quantum-chemical calculations (by HyperChem and Gaussian-98 code). As result the computational models for different molecular conformations were constructed and switching phenomena of FE LB films were explored. These results correspond to known experimental data for switching phenomena of ultra-thin FE LB films and clarify the nature of the ferroelectricity on the molecular level for these new nano-materials.

Keywords:

• thin polymer films
• ferroelectrics
• computational molecular models

ACKNOWLEDGMENTS

This work are supported by INTAS grant No. 03-51-3967 and by RFBR grant No. 05-02-16871.

Notes

∗) Li Ji-Chao, Wang Chun-Lei, and Zhong Wei-Lie, Effect of trifluoroethylene monomers on molecular conformation of poly (vinylidene fluoride-trifluoroethylene) copolymer∗, Chinese Physics, 13(3), (March 2004) [18].

∗40/60 model (6 units out of 16 changed into TrFE).