Critical point in ferroelectric Langmuir-Blodgett polymer films

Authors

Stephen Ducharme, University of Nebraska - LincolnFollow
A.V. Bune, University of Nebraska - Lincoln
L.M. Blinov, Institute of Crystallography of the Russian Academy of Sciences, Moscow, Russia
V.M. Fridkin, Institute of Crystallography of the Russian Academy of Sciences, Moscow, Russia
S.P. Palto, Institute of Crystallography of the Russian Academy of Sciences, Moscow, Russia
A.V. Sorokin, Institute of Crystallography of the Russian Academy of Sciences, Moscow, Russia
S.G. Yudin, Institute of Crystallography of the Russian Academy of Sciences, Moscow, Russia

Date of this Version

January 1998

Comments

Published by American Physical Society. Physical Review B 57, 25-28 (1998). http://prl.aps.org. Copyright © 1998 American Physical Society. Permission to use.

Abstract

The ferroelectric critical point has been found in a ferroelectric polymer by exploring the influence of the electric field on the paraelectric-ferroelectric phase transition. Dielectric and pyroelectric measurements on 30-monolayer-thick films of the crystalline copolymer poly(vinylidene fluoride-trifluoroethylene) grown by Langmuir-Blodgett deposition show a single hysteresis loop below the zero-field phase transition temperature T_c0=80±10 °C, double hysteresis loops between T_c0 , and the critical temperature T_cr=145±5 °C, and no hysteresis above T_cr where the critical electric field is E_cr=0.93±0.1X10⁹ V/m.