Field-induced reversible or irreversible lattice rearrangement of transparent PLZT 9/65/35 ferroelectric ceramics

Crystallographic parameters of the transparent PLZT 9/65/35 ferroelectric ceramics as functions of temperature (T = −190− +60°C) and applied field (E = ±20 kV/cm) as well as their kinetics have been studied by precision x-ray analysis, a method of complex diffraction profile analysis being used. The field-induced cubic to monoclinic transition reversible at temperatures T > T t becomes irreversible in the macroscopic polarized state at T < T t . The absence of macroscopic polarization in thermally depolarized state at cooling below T t in the absence of applied field is explained by random dipole and elastic field in the PLZT lattice caused by heterovalent substitution La3+ → Pb2+.