Identification of paramagnetic Pb+3 defects in lead zirconate titanate ceramics

We report the first observation of positively charged Pb+3 defect centers in lead zirconate titanate (PZT) ceramics using electron paramagnetic resonance. The charged traps were optically generated using ultraviolet light energies roughly corresponding to the band gap of PZT (3.4 eV). The interpretation of the 207Pb+3 hyperfine parameters indicates that the defect’s unpaired electron is approximately 48% localized on the Pb nucleus. These observations may be of considerable importance since they prove that charged carriers created by optical excitation become trapped and form charged paramagnetic defects.