MnO_2掺杂对Ba_(0．6)Sr_(0．4)TiO_3陶瓷介电调谐性能的影响

Influence of Doped MnO_2 on Dielectric Tunability of Ba_(0.6)Sr_(0.4)TiO_3 Ceramics

采用固相反应法制备了掺杂MnO2的Ba0.6Sr0.4TiO3陶瓷,分析了掺杂MnO2的Ba0.6Sr0.4TiO3陶瓷在直流偏置电场下的介电调谐性能。采用XRD和SEM分析了掺杂MnO2的Ba0.6Sr0.4TiO3陶瓷的相结构和微观彤貌,采用HP4192A分析了掺杂MnO2的Ba0.6Sr0.4TiO3介电-温度特性,采用同惠电子公司的TH2816精密电桥测量了介电可调性。结果表明:随着MnO2含量的增加,Ba0.6Sr0.4TiO3陶瓷的致密度和晶粒尺寸都呈现先增大再降低的现象。介电可调性随着MnO2的加入而降低。但品质因子随着MnO2含量的增加呈现先增加再降低的现象。当MnO2含量为4mol％时达到最大值55．1。

Dielectric properties of Ba0.6Sr0.4TiO3 exhibit nonlinearity under an applied DC field. Therefore the dielectric constants exhibit tunable character. This property makes it become an promising material of phase shifters in phased array antenna. The Ba0.6Sr0.4TiO3 ceramics doped with MnO2 were prepared by solid state reaction method. The tunabilities of Ba0.6Sr0.4TiO3 doped with MnO2 were investigated in this work. The phase structure and micro-morphologies were analyzed by XRD and SEM, respectively. The dielectric properties of Ba0.6Sr0.4TiO3 doped with MnO2 were analyzed by HP 4192A impendence analyzer. The tunabilities of Ba0.6Sr0.4TiO3 doped with MnO2 were measured by TH2816 LCR meter.