MgSn_(0.05)Ti_(0.95)O_3-SrTiO_3复相陶瓷的显微结构与微波介电性能

Microwave Dielectric Properties of MgSn_(0.05)Ti_(0.95)O_3-SrTiO_3 Multiphase Ceramics

采用传统固相法制备了不同摩尔配比的(1-x)MgSn0.05Ti0.95O3-xSrTiO3微波介质复相陶瓷材料,研究了复相陶瓷的烧结特性、显微结构和微波介电性能。结果表明:MgSn0.05Ti0.95O3和SrTiO3两相共存,无固溶现象。随着SrTiO3含量的增多,(1-x)MgSn0.05Ti0.95O3-xSrTiO3的相对介电常数(εr)线性增大,品质因数(Q×f)下降,谐振频率温度系数(τf)从负值变为正值。通过调节x值,可以获得近零的τf值。陶瓷的τf变化符合Lichtenecker混合法则。0.98MgSn0.05Ti0.95O3-0.02SrTiO3复相陶瓷在1330℃烧结4h,获得最佳的微波介电性能:εr=19.32,Q×f=193.527 THz,τf=2×10-6/℃。

The microwave dielectric multiphase ceramics of （1-x）MgSn0.05Ti0.95O3-SrTiO3 were prepared by a conventional solid-state route. The sinterability, microstructure and microwave dielectric properties of the multiphase ceramics were investigated. The results show that MgSn0.05Ti0.95O3 and SrTiO3 can co-exist as two phases without any solid solution. The relative dielectric constant （εr） linearly increased, the quality factor （Q× f） decreased and the value of the temperature coefficient of resonance frequency （tf） varied from negative to positive with the increase of SrTiO3 content. In addition, a near-zero rfvalue was obtained by the adjustment of the value ofx. The variation in the the value ofrfof（1-x）MgSno.osTio.9503-xSrTi03 multiphase ceramics followed the Lichtenecker mixture rules. The multiphase ceramic 0.98MgSn0.05Ti0.95O3-0.02SrTiO3 sintered at 1 330 ℃ for 4 h had excellent microwave dielectric properties （εr= 19.32,Q × f = 193.527 THz,τf= 2 × 10-6/℃）.