Effects of Compositional Variations on Antiferroelectric-Ferroelectric Phase Transition of PZST Ceramics

Phase structures, properties and critical parameters of field-induced phase transitions of PZST ceramics near ferroelectric (FE) -antiferroelectric (AFE) phase boundary were studied as a function of composition and temperature. The electric field-induced FE state can maintain metastable state below the critical temperature TFE-AFE after electric field is removed. As temperature increases, the metastable FE state changes to AFE state at TFE-AFE. As Ti content increases, the structure of unpoled PZST ceramics changes from tetragonal AFE phase to rhombohedral FE phase, dielectric constant maximum max and transition temperature TFE-AFE increase, switching field EAFE-FE and EFE-AFE decrease. The forward switching field EAFE-FE and hysteresis E were observed to be dependent on TFE-APE and TC, respectively, and EAFE-FE and E decreased with an associated increasing in TFE-AFE and decreasing in Tc.