Polarization-related electrostrictive coefficients Qhhave been determined for relaxation dielectrics 0.856Sr T1O3-O.144 Bi23TiO3and (K3, 4Bi, 4) (Zn1/6Nb5, 6)O3, and for a simple non-polar perovskite BaZr03by measuring the hydrostatic pressure dependence of the dielectric permittivity. Anomalous variation in the electrostrictive coefficient with temperature and frequency were observed in (K3/4Bi1/4) (Znt/6Nb5/6)O3in the relaxation-temperature region. This behavior can be explained qualitatively with a simple model based on potential barriers separating alternative cation sites. The empirical rule noted previously for ferroelectric perovskites, that the electrostrictive Q coefficient increases with cation order from disordered, through simple and then ordered perovskites is confirmed again in non-polar perovskites.
All Science Journal Classification (ASJC) codes
- Materials Science(all)