Field-induced lead zirconate titanate stannate antiferroelectric-to-ferroelectric phase-switching ceramics

The electric field induced antiferroelectric-to-ferroelectric phase transition of lead zirconate titanate stannate ceramics was investigated by means of dielectric, polarization, and strain hysteresis measurements. Compositions of varying titanium and tin within the general formula (Pb_0.98La_0.02) (Zr_0.66Ti _0.11-xSn_0.23+x)O₃, located in the tetragonal antiferroelectric phase field and near the ferroelectric rhombohedral boundary were prepared. As the applied electric field increased, a sudden increase in both longitudinal and transverse strain was observed with a corresponding change in dielectric constant, loss, and polarization, indicating the transition from antiferroelectric to ferroelectric phase. The longitudinal strain increased continuously into the ferroelectric phase, whereas the transverse strain became negative after the phase change. By defining the phase change field from polarization and high field dielectric constant and loss measurements, the longitudinal strains associated with the phase change for all of the compositions were less than 0.2%. For some compositions, however, the longitudinal strain increased to levels greater than 0.5% with increasing applied field. Owing to the relatively small decrease in transverse strain in the ferroelectric region, the volume strain continued to increase even after antiferroelectric to ferroelectric phase change.