xCa_(0.8)Sr_(0.2)TiO_3-(1-x)Li_(0.5)La_(0.5)TiO_3系陶瓷介电性能的调控  

Regulation and Control on Dielectric Properties of xCa_(0.8)Sr_(0.2)TiO_3-(1-x)Li_(0.5)La_(0.5)TiO_3 Microwave Dielectric Ceramic

作　　者：欧阳文瀚 李玉平[1] 郭爱芬[1] 沈淑娴 陈功田 

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082 [2]郴州功田电子陶瓷技术有限公司,湖南郴州423025

出　　处：《压电与声光》2017年第6期924-927,共4页Piezoelectrics & Acoustooptics

基　　金：湖南省战略性新兴产业科技攻关项目(2014GK1052)

摘　　要：采用烧成法制备了xCa_(0.8)Sr_(0.2)TiO_3-(1-x)Li_(0.5)La_(0.5)TiO_3(CST-LLT)(x=0.4~0.8)系介质陶瓷,表征了其物相组成、结构特征及介电性能。所制备的材料具有钙钛矿结构特征,随着Li_(0.5)La_(0.5)TiO_3组分的减少,1 170~1 260℃烧结的CST-LLT陶瓷介电常数(ε_r)变化范围在154.8~275.2,而品质因数(Q·f)在1 360~1 479GHz内先增加后逐渐减小,谐振频率温度系数(τ_f)变化范围为(-720.6~470.5)×10^(-6)/℃。当x=0.5,烧成温度为1 200℃,保温3h时,可得到理想的介电性能的介质陶瓷:ε_r=230,Q·f=1 455GHz,τ_f=24.5×10^(-6)/℃。The xCa0.8Sr0.2TiO3-（1-x）Li0.5La0.5TiO3（CST-LLT）（x=0.4-0.8）microwave dielectric ceramics were prepared by the solid state reaction method.The phase composition,microstructures and microwave dielectric properties of ceramics were investigated.The results indicate that the prepared ceramics has perovskite structures.The dielectric constantεrvaried from 154.8to 275.2at the sintering temperature of 1 170-1 260℃with the decrease of Li（0.5）La（0.5）TiO3contents.The Q·fvalue increased first and then reduced gradually over the range of 1 360GHz to 1 479 GHz,and the temperature coefficient of resonant frequencyτfvaried from-720.6×10^-6/℃to470.5×10^-6/℃.With x=0.5,CST-LLT ceramics sintered at 1 200℃for 3hexhibited proper dielectric properties ofεr=230,Q·f=1 455GHz andτf=24.5×10^-6/℃.

关 键 词：Li0.5La0.5TiO3 固相反应 介电性能 钙钛矿结构 介质陶瓷 

分 类 号：TM28[一般工业技术—材料科学与工程] TQ174.75[电气工程—电工理论与新技术]