Photostriction in lead lanthanum zirconate titanate ceramics enhanced by the additive effect

(Pb-0.97, La-0.03) (Zr-0.52, Ti-0.48)(1-0.03/4)O-3 ceramics doped with 0-10 mol% Ta were sintered at 1200 degrees C for 2h and then heat-treated in nitrogen at 900 degrees C for Ih to investigate the change in the photostrictive response upon illumination with wavelength of 300-400 nm. Before the heat treatment in nitrogen, both photovoltaic current and voltage were increased by doping with Ta, revealing maxima around 1.5 mol% of doped Ta, A very similar change upon doping with Ta was observed in piezoelectric properties such as electromechanical coupling factor (k(33)), Strain constant (d(33)) and dielectric constant. On the other hand, the heat treatment in nitrogen heightened the photovoltaic response, on the whole, regardless of the amount of doped Ta, but scarcely affected the piezoelectric parameters. Due to an additive effect of the doping with Ta and the nitrogen-treatment, the photovoltaic properties were further enhanced and hence the photostriction response was confirmed to be markedly improved.