掺钙-钛酸钡陶瓷缺陷化学的研究

用高温平衡电导率及正电子湮没寿命谱量测研究了钙离子的两种置换类型对钛酸钡缺陷结构、电性能的影响及机理。结果表明：等价置换能够改变钛酸钡氧化、还原反应生成焓，受主置换对钛酸钡电导率曲线、正电子淹没寿命谱均有显著影响；少量受主置换可以使在强还原气氛下烧结钛酸钢材料的绝缘电阻提高近１０个数量级。该材料可做为进一步研究贱金属电极独石电容器的基础。

On the Defect Chemistry of Ca-Doped BaTiO_3 Ceramics

In this paper, the measurements of high temperature conductivity and positron annihilation are used to analyze the effect of two kinds of substitution(equivalent, non-equivalent) of Ca2 on the defect structure, and electric properties of BaTiO3, The results show:the equivalent substitution of Ca2 can change the enthalpy of oxidation and reduction reactions of BaTiO3.Accepted dopants have marked influence on the electric conductivity and positron lifetime of the material. The accepted solid solubility of Ca2 in BaTiO3 are given based on the analysis of defect chemistry. Equivalent substitution of Ca2 in BaTiO3 have little effect on the properties of anti-reduction. A few amounts of accepted substitution may increase the resistivity more than ten orders of magnitude for the materials sintered in strong reducing atmosphere. This material can further be improved into monolithic capacitors with base-metal electrods.