Photostriction effect in perovskite crystals.

摘要

This work is designed to understand the mechanism of the photostriction effect in perovskite crystals aiming at actuator applications. The photovoltaic effect has been observed in certain ferroelectrics, from which a constant electromotive force is generated by uniform illumination with the wavelength corresponding to the fundamental or impurity absorption region. This voltage is generated in the direction of polarization of the crystal and disappears in the paraelectric region under uniform illumination and the magnitude of the induced voltage is proportional to the crystal length in the polarization direction and is much greater than the band gap energy of the crystal. The asymmetric crystal generating photovoltaic force is also piezoelectric; therefore, a photostriction effect is expected as a superposition of the bulk photovoltaic effect and the inverse piezoelectric effect.;The first phase of this work focused on the bulk photovoltaic effect in bulk PLZT(3/52/48) ceramics. In this study, the photovoltaic current, the corresponding voltage and the photostrictive response were measured in PLZT ceramics doped with WO