Radiation effects on lead-containing perovskite ceramics

Optical spectra and dielectric parameters are used to study PLZT X/65/35 (X=4. 5-11 at. % La) and PSN ceramics subject to gamma- electron-, and neutron irradiation. In neutron-irradiated ceramics stable defects, maintained at annealing up to 700 °C are manifested by a gradual shift of extinction edge near the fundamental absorption to longer wavelengths and by reduced polarization values. The thermal dependence of the extinction edge in reference samples of PLZT and PSN has been determined to be ca. 0. 10 nm/deg (0. 9 meV/deg) and 0. 125 nm/deg, respectively in the range 20-500°C. In PLZT 6. 5-8/65/35 ceramics a defect enforced phase transformation from the initial rhombohedral structure to "quasicubic" with essential broadening of the phase transition takes place.