OPTICALLY INDUCED ABSORPTION AND PARAMAGNETISM IN LEAD LANTHANUM ZIRCONATE TITANATE CERAMICS

Electron paramagnetic resonance (EPR) and photothermal deflection spectroscopy measurements have been performed to identify the nature of the centers responsible for the subgap absorption in both unilluminated and ultraviolet (UV) illuminated lead lanthanum zirconate titanate (PLZT) ceramics. In the PLZT ceramics we find that the absorption near 2.6 eV is correlated with the presence of Ti+3 centers. UV exposure of these ceramics leads to the generation of two charged paramagnetic defects, Pb+3 and Ti+3, as well as an increased subgap absorption. These observations demonstrate strong correlations between the UV-induced EPR and optical responses, suggesting that both are due to the same trapping centers.