PLZT陶瓷在多能场耦合下的光致伸缩效应

为了消除高能光束照射下镧改性锆钛酸铅(PLZT)陶瓷的光致形变与光生电压之间的迟滞现象,建立了一种多能场耦合下的新型光致伸缩本构方程,实验研究了影响该迟滞现象的各种因素。首先,对光照作用下光-电-热-力多能场耦合作用进行理论分析,建立了光致伸缩效应的本构关系;然后,对反常光生伏特效应、光焦热效应、热释电效应、热膨胀效应以及压电效应进行理论推导,得到了新型的光致伸缩本构方程;最后,通过温度屏蔽实验和光致伸缩静态实验验证了提出的本构方程。实验表明:PLZT陶瓷表面的温升是造成迟滞现象的主要原因;实验曲线变化趋势与理论结果一致,显示理论模型合理;消除温度影响后,实验所用PLZT样品的光致形变达到饱和所用的时间约为10s。结果表明,降低PLZT陶瓷表面的温升能有效消除迟滞现象,提高光致形变响应速度;建立的光致伸缩本构方程为PLZT陶瓷驱动控制研究提供了理论基础。

Photostrictive effect of PLZT ceramic at coupling of multiple energy fields

To eliminate the hysteresis phenomenon between the photodeformation and the photovoltage of PLZT (Lead Lanthanum Zirconate Titanate) under the irradiation of high energy light, a novel photostrictive constitutive equation in multi-energy fields was established and the influence factors of the hysteresis phenomenon were investigated by experiments. Firstly, the light-thermal-electric-elastic coupling mechanisms of the photostrictive effect under a lighting were analyzed theoretically and the constitutive relationship of photostrictive effect was established. After that, a novel constitutive equation was obtained by the derivation of anomalous photovoltaic effect, thermal effect, pyroelectric effect, thermal expansion effect and piezoelectric effect. Finally, the photostrictive constitutive equation was validated through the temperature screening test and photostrictive static experiments. Experimental results indicate that the temperature rise of PLZT ceramic is the main reason of hysteresis phenomenon; and the variation trends of experiment curves are agreed well with the theoretical results, which confirms the reasonability of the theoretical model. Moreover, the photodeformation of the PLZT in the experiment takes about 10 s to reach saturation after eliminating the temperature rise. It shows that reducing the temperature rise effectively eliminates the hysteresis phenomenon and improves the response speed of photodeformation. The novel constitutive equation provides a theoretical basis for driving and controlling of PLZT ceramics.