SHALLOW PB3-ZIRCONATE-TITANATE FERROELECTRICS( HOLE TRAPS IN LEAD)

A combination of electron paramagnetic resonance and band structure ca lculations is used to show that the Pb2+ ions in lead zirconate titana te materials can act as shallow hole traps to give Pb3+ centers. The P b3+ centers are created by optical illumination and are found to be me tastable at room temperature. Their decay kinetics follow a stretched exponential function which suggests dispersive transport. The traps ha ve the same character as the upper valence band which is formed from t he hybridization of Pb s and O p states.