Research On Photo-induced Characteristics Of 0-3 Polarized PLZT Ceramics

The lead lanthanum zirconate titanate(PLZT)materials poling with 0-3 polarization exhibits photostriction by superposition of anomalous photovoltaic effect and converse piezoelectric effect under ultraviolet light illumination.The plate deflections generated by UV light are due to the nonuniform mechanical strains that are induced by the inhomogeneous electrical field strength along thickness direction.The PLZT actuators do not require hard-wire wire connections which avoid the unfavorable factors such as external electromagnetic field.Photostrictive actuators,which can transducer from optical energy to electrical energy and wireless remote control,have important research value and wide prospect of engineering application.In this paper,the photo-induced characteristics of 0-3 polarized PLZT ceramics under UV light are studied by the method of combining the theoretical,the experiment and the simulation.The coupling principle and relationship between 0-3 polarized PLZT ceramic optical-thermo-electric – mechanics multi-physical field are analyzed in depth,and the constitutive equations of 0-3 polarization PLZT ceramic linear and nonlinear are elaborated.Set up 0-3 polarized PLZT ceramics static experiment platform and experimental investigated the change rule of the photovoltage,photocurrent and bending deformation and the hysteresis phenomenon between the photovoltage and bending deformation.Giant negative voltage,current and reverse bending deformation are detected when light switched off.Then experimental tested the photo-induced characteristics when temperature of PLZT ceramics controlled by air cooling device.Compared with no air cooling,the decrease of temperature will result in the decrease of the saturation voltage in the illumination phase,but the effect on the bending deformation is not very obvious.The negative voltage in the stop stage is caused by the superposition of the pyroelectric voltage and 0-3 polarization PLZT ceramic discharge.Finally based on constitutive equation of 0-3 polarized PLZT ceramic multi-physical field constitutive equation and the RC circuit,established the mathematical model contain more time parameters and fit parameters from experimental data.The rationality of the model is verified by comparing the experimental curves with the theoretical curves.