PLZT陶瓷的介电弛豫行为与A位有序  

DIELECTRIC RELAXATION BEHAVIOR AND A-SITE ORDERING OF La-MODIFIED LEAD ZIRCONATE TITANATE RELAXOR

作　　者：方菲[1] 桂红[1] 张孝文[1] 

机构地区：[1]清华大学材料科学与工程系

出　　处：《硅酸盐学报》1995年第6期599-604,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重点项目

摘　　要：用传统粉末工艺合成了（Ｐｂ＿（０．８６５）Ｌａ＿（０．０９））（Ｚｒ＿（０．６５）Ｔｉ＿（０．３５））Ｏ＿３陶瓷（ＰＬＺＴ９／６５／３５）。Ｘ射线研究表明：试样中存在着Ａ位准体心立方有序超结构，有序畴的平均尺寸为１０～２０ｎｍ。测定了１０个频率下介电常数与温度的关系，并将介电常数最大值的温度Ｔ＿ｍ与对应的频率ｆ用Ｖｏｇｅｌ－Ｆｕｌｃｈｅｒ公式拟合，得到物理上合理的激活能及指数前项值，这表明试样的介电弛豫行为与自旋玻璃态类似。基于Ａ位有序超结构及类似于自旋玻璃态的极化行为，对试样的极化全过程进行了探讨。Pb_(0.865) La_(0.09))(Zr_(0.65) Ti_(0.35)) O_3 ceramics was synthesized by conventional powder processingtechnique.X-ray diffraction investigation reveals that A-site body-centered pseudo-cubic ordered superstruc-ture exists in the sample with an average size of 10～20nm. The dielectric constant as a function of tempera-ture was measured for ten different frequencies. The frequency dependence of the temperature of the dielectricconstant maximum was analyzed based on the Vogel-Fulcher relat ionship,obtaining reasonable resuIts forboth activation energy and preexponential factor. It is suggested that the relaxor behavior of the PLZT ce-ramics is similar to that of spin glasses. Based on these results, the polarizatiOn process is discussed.

关 键 词：锆钛酸镧陶瓷 介电驰豫 驰豫铁电体 陶瓷 

分 类 号：TQ174.756[化学工程—陶瓷工业] TQ174.758[化学工程—硅酸盐工业]