摘要
采用硝酸钡、硝酸锶、钛酸丁酯和柠檬酸为原料的配合物溶胶凝胶方法制备了(Ba1-xSrx)TiO3(BST)陶瓷。实验结果表明,BST粉体合成温度及烧结温度分别为700及1250℃,均低于传统工艺的相应温度。Sr含量x≥0.40,(Ba1-xSrx)TiO3陶瓷的相结构为立方钙钛矿相;Sr含量x<0.40,(Ba1-xSrx)TiO3陶瓷的相结构为四方钙钛矿型。(Ba1-xSrx)TiO3(0.5≤x≤0.70)陶瓷的电容率随温度变化曲线,说明存在由铁电四方相到顺电立方相的相变。且随锶(Sr)的摩尔量x的增加,(Ba1-xSrx)TiO3陶瓷样品的相变温度向低温方向移动,相变温度Tc的移动关系为Tc=394.1-272.6x(K)。
The Ba1-xSrxTiO3 （BST） ceramics of various compositions were prepared by sol-gel-derived powders. The microstructure and dielectric properties of Ba1-xSrxTiO3 ceramics with X from 0.3 to 0.5 have been investigated. Experimental results showed that the synthetic temperature of Ba1-xSrxTiO3 powder is 700℃, which is much lower than that by the conventional solid-state reaction method. The Ba0.60 Sr0.40 TiO3 powder obtained is a cubical phase. The typical cubic phase structure with x≥0.4 and tetragonal phase structure with x〈0.4 in the XRD pattern of the Ba1-xSrxTiO3 ceramics sintered at 1573K. The sintering temperature of the Ba0.60Sr0.40TiO3 powder falls to 1250℃. Sr acts as substitution to replace Ba in the A site of ABO3 perovskite structure, leading to a shift of Curie temperature （To） to lower temperature with increasing Sr content. The correlation of Curie temperature （Tc） dependence of Sr content （x） for the Ba1-xSrxTiO3 ceramics can be expressed as Tc=394.1- 272.6x （K）.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第3期389-392,共4页
Journal of Functional Materials
基金
国家重点基础研究发展计划(973计划)资助项目(2002CB613304)
关键词
钛酸锶钡陶瓷
溶胶凝胶
介电性能
相变
barium strontium titanate
sol-gel
dielectric property
phase transition
