PMN-BT陶瓷的介电性能和相变温度

Dielectric Properties and Phase Transition Temperature of PMN-BT Ceramics

制备了一系列ＰＭＮ－ＢＴ陶瓷，系统地研究了ＢＴ含量的变化对介电性能和相变温度的影响．ＰＭＮ－ＢＴ陶瓷的相变温度与组成呈“Ｕ”型变化曲线．相变温度的异常变化是由于系统中存在Ｂａ（Ｍｇ１／３Ｎｂ２／３）Ｏ３顺电微区所致．ＰＭＮ－ＢＴ陶瓷的介电弛豫特性随ＢＴ的增加经历了一个由弱变强，再由强变弱的过程．对由两种钙钛矿化合物构成的铁电固溶体相变温度的变化规律进行了讨论．

The dielectric properties of PMN-BT solid solution ceramics were systematically studied. The change of the transition temperature with composition is in the form of 'U' curve and the possible cause may be existing of paraelectric phase Ba(Mg1/3Nb2/3)O-3 in PMN-BT ceramics. The effects of composition on dielectric relaxation for PMN-BT ceramics were studied. With increasing BT content, dielectric relaxation of PMN-BT ceramics was increasing first, then decreasing. The characteristics of phase transition temperature of the ferroelectric solution composed of two perovskite compound were also discussed.