Interrelationship between self-heating and ferroelectric properties inPZT ceramics during polarization reorientation

Abstract

Ferroelectric ceramics when driven under high electric field have theirferroelectric properties modified due to the polarization reorientation, whichinduces the fatigue effect or domain depinning process. The self-heating processis another important characteristic that can be observed in this situation. Inthis work, we investigated the interrelationship among self-heating and bothfatigue and depinning processes in PZT ceramics, calculated from the P-Ehysteresis loop measurements. It was found that the fatigue and depinningprocesses are reflected mainly in the temperature trend of the sample duringpolarization reorientation at 60 Hz and they have the same profile in bothcases. The heating process might be visualized as resulting from domain rotationin a viscous medium. For `hard' PZT, the self-heating accelerated a depinningprocess. While the electric field cycles were accumulated the heat generated bythe sample increased the complex defect mobility. In consequence, the domaincould be depinned, increasing the amplitude rotation of the domains. For `soft'PZT, the self-heating accelerated a fatigue process by space charge motion.