Open AccessElectrical polarization phenomena, dielectric relaxations and structural transitions in a relaxor-ferroelectric terpolymer investigated with electrical probing techniques
Author(s) -
Thulasinath Raman Venkatesan,
Anna A. Gulyakova,
Peter Frübing,
Reimund Gerhard
Publication year - 2019
Publication title -
materials research express
Language(s) - English
Resource type - Journals
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab5352
Subject(s) - materials science , ferroelectricity , dielectric , electric field , condensed matter physics , polarization density , polarization (electrochemistry) , poling , dipole , phase transition , glass transition , dielectric spectroscopy , nuclear magnetic resonance , polymer , magnetization , optoelectronics , chemistry , magnetic field , physics , electrode , organic chemistry , quantum mechanics , electrochemistry , composite material
Dielectric Relaxation Spectroscopy (DRS) and Thermally Stimulated Depolarization Current (TSDC) measurements were employed to study dielectric-relaxation processes, structural transitions and electric-polarization phenomena in poly(vinylidenefluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer films. Results from DRS confirm the existence of two separate dispersion regions related to a para-to-ferroelectric phase transition and to the glass transition. The dipolar TSDC peak correlates with the loss peak of the α relaxation that represents the glass transition. The electric polarization calculated from the dipolar TSDC peak (glass transition) shows a non-linear electric-field dependence and saturates at high electric poling fields. As the observed behaviour is essentially the same as that of the electric polarization obtained from direct polarization- versus -electric-field hysteresis measurements, TSDC experiments are also suitable for studying the polarization in relaxor-ferroelectric polymers. A saturation polarization of 44 mC m −2 was found for an electric field of 190 MV m −1 .