新型钽酸锂薄膜热释电系数测试研究

用溶胶-凝胶法在导电的Pt／Ti／SiO2／Si衬底上制备了一种1μm厚的新型钽酸锂薄膜；采用直流电压对新制备的薄膜进行了极化；选择了电荷积分法，设计了与钽酸锂薄膜阻抗匹配的测试电路，组建了新的水浴搅拌加热的热释电系数测试系统，完成了薄膜的热释电系数测试。测试结果表明，钽酸锂薄膜有较好的热释电特性，在6V、15min极化条件下，测得热释电系数为122．8μC／m^2K，测试精度为1．14％，说明新开发的测试系统对新材料热释电系数测试具有重要的实用价值。实验误差分析表明，采用适合的搅拌速度和加热功率、采用更高精度的温度传感器，设计完全匹配的测试电路，是进一步提高钽酸锂薄膜热释电系数测试精度的最有效途径。

Pyroelectric coefficient measurement of novel lithium tantalate thin film

A novel 1μm thickness lithium tantalate thin film sample was prepared on a Pt/Ti/SiO2/Si substrate using sol-gel method. The sample was polarized by DC voltage. The pyroelectric coefficient of the sample was obtained adopting charge integration method, a measurement circuit matched with the impedance of the lithium tantalate thin film was designed, a new water stirring and heating measurement system was built, and the pyroelectric coefficient measurement of the sample was completed. Measurement results show that the lithium tantalate thin film has perfect pyroelectric characteristic; the measured pyroelectric coefficient is 122.8μC/cm^2K and the measurement error is 1.14% under the polarization condition of 6 V, 15 min. The measurement results verify that the newly developed measurement system has important application value to the pyroelectric coefficient measurement of new materials. Measurement error analysis shows that the most effective methods to improve the measurement resolution of the lithium tantalate thin film pyroelectric coefficient measurement system include adopting proper stirring speed and heating power, using a higher resolution temperature sensor, and designing a totally matched measurement circuit.