Memory effects in dielectric and anelastic measurements of PLZT

Anelastic (1-10 kHz) and dielectric (200 Hz-1 MHz) relaxation measurements on ceramic PLZT 9/65/35 are presented. The anelastic and dielectric measurements are extended between 140 and 560 K, and exhibit the typical features of a relaxor transition slightly above room temperature. The peak in the elastic compliance, however is about 30 K below the relaxor peak in the dielectric susceptibility, indicating an increasing role of the non-180degrees polarization dynamics at lower temperature. Both the dielectric and elastic susceptibilities exhibit comparable aging and memory effects. The possible influence on aging and memeory from relatively mobile defects like O vacancies is discussed.