铁电复合物PZT/P[VDF(77)-TrFE(23)] 退极化场系数的电场与温度效应

EFFECTS OF ELECTRIC FIELD AND TEMPERERATURE ON DEPOLARIZATION FIELD COEFFICIENT IN PZT/P[VDF(77)-TrFE(23)] FERROELECTRIC COMPOSITES

用自建的适合厚片材料测量的介电测试系统研究了不同组分含量的ＰＺＴ／Ｐ［ＶＤＦ（７７）－ ＴｒＦＥ（２３）］ ０－３型铁电复合物厚片介电系数的电场和温度依赖性在低电场和室温附近的温度范围，由 Ｂｒｕｇｇｅｍａｎ方程预测的介电系数和实验值较为接近．Ｙａｍａｄａ模型通过退极化场系数 Ｌｚ的变化，可 拟合复合物介电系数的电场和温度依赖关系结果显示Ｌｚ随电场的升高而降低，随温度的改变（升温、 降温过程）而与复合物介电系数类似。

A system for measuring dielectric permittivity of thick films and data processing method have been set up. The relationships between the dielectric permittivity and the electric field as well as temperature for thick PZT/P[VDF(77)-TrFE(23)] 0-3 composite films were investigated. Bruggeman equation is suitable for the prediction of dielectric permittivity of composite at low electric field and around the ambient temperature while Yamada model can be used to best fit the measured dielectric permittivities which depend on the measuring electric field and temperature with the change of depolarization field coefficient L.' It is found that L. decreases as the electric field rises. The variatidn of L. with temperature shows a distinct thermal hysteresis phenomenon similar to that appeared in dielectric permittivity of the composite.