BaTiO_3-Yb_2O_3-MgO系陶瓷居里点移动机理研究  

Study on the Mechanism of Curie Temperature Shifting in BaTiO_3-Yb_2O_3-MgO System Ceramics

作　　者：杜旻[1] 袁颖[1] 王升[1] 张树人[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,四川成都610054

出　　处：《压电与声光》2008年第4期450-452,455,共4页Piezoelectrics & Acoustooptics

摘　　要：通过在BaTiO3陶瓷中单独添加Yb2O3或复合添加MgO／Yb2O3，研究了不同含量Yb^3＋掺杂对BaTiO3陶瓷居里点的影响。研究表明，在BaTiO3陶瓷中单独添加Yb^3＋使陶瓷介电常数减小，介电常数温度特性改善，但不会影响居里温度。而同时添加Mg^2＋与Yb^3＋时，BaTiO3陶瓷的温度特性能满足X8R（-55～150℃，电容变化率△C／C≤±15％，）标准，且系统的居里点随Yb^3＋含量增大而升高，掺入Yb^3＋每增加1％（摩尔比）使居里点提高2℃。研究认为，BaTiO3居里点向高温方向移动是由于在具有壳一芯结构BaTiO3陶瓷中，Yb^3＋取代Ti^4＋使晶粒壳晶胞体积增大，对晶粒芯产生张应力所致。In this paper, the effects of different amounts of Yb^3＋ substitution on the Curie temperature of BaTiO3 ceramics were investigated. It was observed that the dielectric constant was decreased and the capacitance-temperature characteristic was improved by only Yb^3＋ addition. However, Yb^3＋ replacement had little effect on the Curie temperature. On the other hand, when Mg^2＋ and Yb^3＋ were added to BaTiO3 simultaneously, the temperature characteristic of BaTiO3 ceramics could satisfy the X8R specification. Moreover, the Curie point was shifted towards higher temperatures with increasing Yb^3＋ amounts by the rate of 2℃ with an addition of 1% Yb^3＋ . It was revealed that the increase of Curie temperature of BaTiO3 ceramics with core-shell structure was resulted from the tensile stress in grain core caused by the expansion of crystal cell in grain shell when Yb^3＋ replaced Ti^4＋ of BaTiO3.

关 键 词：BATIO3 X8R 介电性能 居里点 

分 类 号：TM534[电气工程—电器]