Preparation of Ba_xSr_1-xTiO₃  Solid Solution Doped with Ca²⁺ and Mn²⁺ by Sol-gel Process

Liu Shengfeng,  Liu Junsheng,  Han Xiaozhao,  Zhang Xingfa
(School of Chemical Engineering, Hefei University of Technology,  Hefei  230009)

Abstract  Kinetic parameters of Ca²⁺ and Mn²⁺ Codoping Ba_xSr_1-xTiO₃ to prepare Ba_0.4Sr_0.5Ca_0.08Mn_0.02TiO₃ solid solution was studied. Results indicate that the structure of microcrystals is transformed from disorder into order as heating temperature increases, and crystallites become regular tetragonal system. The crystallization temperature increases when heating rate is raised and apparent activation energy of crystallization is 152.04kJ/mol. By only using glacial acetate acid to dissolve barium and strontium hydroxide, the sol-gel of Ba_0.4Sr_0.5Ca_0.08Mn_0.02TiO₃ can be derived, and the maximum mole ratio of chelating agent content on the sol-gel is about 1.0.

Key words  Ba_xSr_1-xTiO₃,  Sol-gel process,  Kinetics,  Doping

Ca²⁺和Mn²⁺共掺杂Ba_xSr_1-xTiO₃制备固溶体Ba_0.4Sr_0.5Ca_0.08Mn_0.02TiO₃

刘胜峰  刘俊生  韩效钊  张兴法
(合肥工业大学化工学院  合肥  230009)

摘要  研究了用溶胶-凝胶法制备Ca²⁺﹑Mn²⁺共掺杂Ba_xSr_1-xTiO₃合成 Ba_0.4Sr_0.5Ca_0.08Mn_0.02TiO₃固溶体的动力学参数，结果表明：热处理温度升高，微晶结构从无序向有序转变，同时晶粒呈规则的四边形态。提高升温速率，晶化峰顶温度升高，晶化放热峰向高温方向移动。由立方相向四方相转变的煅烧温度约为700～850°C，晶化表观活化能为152.04kJ/mol。只有使用冰醋酸溶解钡﹑锶的氢氧化物才能制得Ba_0.4Sr_0.5Ca_0.08Mn_0.02TiO₃完全固溶体，螯合剂加入量的最大摩尔比为1.0。
关键词  Ba_xSr_1-xTiO₃  溶胶-凝胶法  动力学  掺杂

刘胜峰  男，42岁，博士，教授，主要从事无机功能材料的低温合成与动态过程研究。
教育部留学回国人员科研启动基金(教外司留(2002)247号)，合肥工业大学人才引进专项基金项目
2003-05-13收稿，2003-09-05接受

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