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

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