Radiation-Induced effects in transparent ferroelectric ceramics

PLZT and PSN ceramics have been exposed to 7-radiation (energy ^1.15 MeV, dose up to 3 - 10⁹rad), electron flux (4.5 MeV, dose up to 3, 10¹⁸electr./cm²) and fast neutrons (> 0.1 MeV, dose up to 10¹⁸n/cm²). The irradiated material was used to study radiation effects on dielectric parameters (a and tg6 were measured at frequencies from 1 kHz to 5 MHz), polarization (dielectric hysteresis quasistatic loops) and non-linear optical properties (I_2W)- The measurements were made in the region of phase transition as well as to examine annealing of radiation-induced defects. As compared to PLZT the PSN ceramics is more resistant to radiation, the most sensitive PLZT compounds being with 7 X 9.5 at.% of La. Obtained results are explained by the change of ion charge, redistribution of vacancies in A and B sublattices of PLZT and by possible ion ordering in sublattice B of PSN with account for intrinsic fields in the relevant compounds.