Ba1-xCaxTiO3陶瓷的介电性和正电子湮没研究  

Dielectric Characteristics and PAT Studies of Ba_(1-x)Ca_xTiO_3 Ceramics

作　　者：宋桂林[1] 常方高[1] 房坤[1] 秦萍[2] 曾齐军[2] 

机构地区：[1]河南师范大学物理与信息工程学院,河南新乡453007 [2]信阳师范学院物理系,河南信阳464000

出　　处：《河南师范大学学报（自然科学版）》2008年第3期45-48,共4页Journal of Henan Normal University(Natural Science Edition)

基　　金：国家自然科学基金(60571063);留学归国基金(教外司留[2005]55)

摘　　要：采用固相反应法制备Ba1-xCaxTiO3陶瓷样品,运用X射线衍射技术进行物相分析,利用HP4294A阻抗分析仪测量样品在室温下的介电特性随频率和Ca2+掺杂量的变化.实验结果表明:Ca2+掺杂可以提高BaTiO3陶瓷的介电常数随频率变化的稳定性,降低BaTiO3陶瓷的介电损耗,随着掺杂量增加,效果就越明显;用正电子湮没寿命谱学的方法研究样品中的结构缺陷与掺杂量的变化关系.分析了样品的微观结构与掺杂量的大小有关.Ba1-xCaxTiO3 ferroelectric ceramics are prepared by conventional solid state reaction method. X-ray diffraction is carried out to characterize the crystal structure. Frequency dependence of dielectric properties of Ba1-x Cax TiO3 samples at room temperature is measured in a frequency range from 100Hz to 1MHz using a HP4294A precision impedance analyzer. Smaller frequency dependence and lower dielectric loss are observed with samples of higher Ca content. The effects of Ca^2＋ on the crystal structure and defect properties of Ba1-xCaxTiO3 ceramics have been further investigated using positron annihilation technique.

关 键 词：正电子寿命 介电常数 介电损耗 

分 类 号：O656.32[理学—分析化学]