<title>Fatigue effect in bulk ferroelectrics</title>

Abstract

We have used a kinetic approach to the fatigue phenomenon in ferroelectrics for the analysis of the evolution of switching current and strain hysteresis loops in bulk PZT ceramics and the switching current in PZN-PT single crystals during cyclic switching. It is proposed that fatigue is due to a redistribution of the local internal bias field during cycling (spatially non-uniform imprint effect). The model considered is based on the fact that during cycling the ratio of the states with opposite direction of polarization ranges over the sample area. The local value of this ratio defines the change of the internal bias field at the given point during the switching cycle considered. Thus the spatial distribution of the internal bias field depends on the domain evolution prehistory. We have investigated by computer simulation the self-consistent change of the internal bias field distribution function with cycling, which leads to fatigue. The mathematical treatment of the switching current data allows us to extract the information about the evolution of the field distribution function. The fatigue-induced change of the strain loops is explained by a strong unipolarity of the growing frozen domain area, which has been predicted by our simulations. The analysis of experimental data confirms the validity of our model.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.