粗晶粒BaTiO_3陶瓷的微观结构及电学性能  

Microstructure of Coarse-grained BaTiO_3 Ceramics and Its Effects on Electric Properties

作　　者：李伟[1] 徐志军[1] 初瑞清[1] 付鹏[1] 郝继功[1] 

机构地区：[1]聊城大学材料科学与工程学院,山东聊城252059

出　　处：《材料科学与工程学报》2009年第6期952-954,958,共4页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(50602021);国家高技术研究开发资助项目(2006AA03Z437);聊城大学科研基金资助项目(X071001)

摘　　要：以钛酸丁酯和乙酸钡为原料用溶胶-凝胶法制备了BaTiO3纳米粉体,并烧结了不同晶粒尺寸的陶瓷,研究了不同烧结温度下BaTiO3陶瓷的微观结构及尺寸效应对电学性能的影响。结果表明:溶胶-凝胶法可以在较低的温度(700℃)下合成BaTiO3纳米粉体,平均粒径25nm;BaTiO3陶瓷的晶粒尺寸直接影响其电学性能,随晶粒尺寸的增大,剩余极化,压电常数,机电耦合系数,机械品质因数逐渐提高,居里温度向高温区偏移;当晶粒尺寸达到50μm时,陶瓷相对密度为95.6%,d33可达168pC.N-1,kp=24.8%,Qm=425,Tc=122℃。BaTiO3 nanopowder was synthesized by sol-gel process,using Ti（OBu）4 and Ba（Ac）2 as raw materials.Crystal size was 25nm when the powder was calcined at 700℃.BaTiO3 ceramics with different grain sizes were sintered.Size effects on electric properties were studied.Results confirm that the microstructure of ceramics,especially the grain size has great effect on electric properties,such as piezoelectric constant and electromechanical coupling factor,and mechanical quality factor was enhanced and Curie temperature shifted to a higher temperature as the grain size increased. The properties for the ceramics with grain size of 50μm are as following： relative density （95.6%）, piezoelectric constant （daa = 168pC· N-1 ）, electromechanical coupling factor（kp = 24.8%）, mechanical quality factor （Qm = 425） and Curie point （Tc = 122℃ ）.

关 键 词：钛酸钡 溶胶-凝胶 压电性能 居里温度 晶粒尺寸 

分 类 号：TM21[一般工业技术—材料科学与工程]