<title>Corona poling of a ferroelectric polymer (PVDF)</title>

Abstract

In this work, we applied constant current corona poling in order to study potential buildup and polarization switching in uniaxially and biaxially stretched PVDF. Relaxation processes have been studied by the thermally stimulated depolarization (TSD) current method. It has been confirmed that the poling and switching processes consisted of three stages. A simple technique has been suggested to find the P(E) hysteresis curves and obtain static and dynamic dielectric constants, as well as the coercive Ec and saturated Es fields in one sequence of experiments. The method can be used for any material with the hysteresis-like field dependence of polarization. It has been found that there are three components of the residual polarization in PVDF, namely the stable ferroelectric component, the slowly relaxing one and the unstable component. Two TSD peaks have been observed immediately after poling, but two more peaks appeared in the samples stored for a long time. It follows from our results that very slow redistribution of charges and polarization takes place in PVDF until the electret and ferroelectric components of polarization are finally separated, both accompanied by the trapped charges.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.