摘要
建立起适合厚片材料测试的非线性介电测试系统和相应的数据处理方法；测得了在不同场强和温度下ＰＺＴ／Ｐ［ＶＤＦ（７７）ＴｒＦＥ（２３）］０３ 型铁电复合物厚片的二阶非线性介电系数；根据Ｙａｍａｄａ 模型拟合（一阶） 介电系数的电场和温度依赖关系得到了退极化场系数Ｌｚ，并由此计算了在各电场和温度下作用于陶瓷粒子的局域场；结果说明在介电系数测试过程中，未预极化复合物试样的二阶非线性介电系数起源于分散相陶瓷粒子在局域场作用下发生的部分极化反转．
A system for measuring nonlinear dielectric permittivity of thick films and data processing method have been set up. The second order nonlinear dielectric permittivities for thick PZT/P[VDF(77) TrFE(23)] 0 3 ferroelectric composite films were measured. Yamada model can be used to best fit the measured dielectric permittivities which depend on the electric field and temperature with the change of depolarization field coefficient L z. The local electric field applied to ceramic particles was been calculated based on L z at various electric fields and temperatures. The result shows that the second order dielectric permittivity of unpoled composites arises from the partial polarization reversal in ceramic particles under the local electric field during the measurement of nonlinear dielectric permittivity.
基金
国家自然科学基金资助
香港RGC和香港理工大学资助
关键词
极化反转
铁电复合物
非线性介电系数
电场
polarization reversal, ferroelectric composite, second order nonlinear dielectric permittivity
