Models for the dependence of switching time on electric field in ferroelectric polymers

The change in macroscopic polarization of ferroelectric polymers, when the applied field E is increased, is considered to be due to the growth of certain saturated domains at the expense of less favored adjacent domains with different directions of polarization. The rate of switching from one state of polarization to another can be viewed as a thermally activated process where the activation energy depends approximately linearly, with a negative slope, on E. Some data for PVDF (polyvinylidene fluoride) are analyzed to demonstrate this fact. Molecular models, based on statistical thermodynamical considerations of polarization domains of cylindrical shape, are discussed