The thermal depolarization behavior of PMN-PT-BZT relaxor ferroelectric ceramics from the standpoint of domain structure transitions

Abstract

The thermal depolarization behavior of PMN-PT-5BZT relaxor ferroelectric ceramics was studied, and the depolarization mechanism was discussed from the perspective of domain structure transitions. In addition to the transition from MPB structure at room temperature to cubic phase at high temperature, the structure symmetry of PMN-PT-5BZT ceramics has no obvious change with increasing temperature. However, the ceramic had experienced a transition process from ferroelectric state to nonergodic relaxor state, and then to ergodic relaxor state. The results of temperature dependence of ferroelectric properties showed that the depolarization temperature Td corresponds to the transition temperature TF-NR from ferroelectric state to nonergodic relaxor state, and there is an obvious dielectric abnormal peak at this temperature, which is mainly due to the depolarization behavior caused by the decrease of macrodomain size and the beginning of transition to nanodomains.