CaO掺杂对63ST-37LA微波介质陶瓷性能的影响

Effect of CaO Doping on the Properties of 63ST-37LA Microwave Dielectric Ceramics

采用固相反应法,研究了Ca O掺杂对0.63Sr Ti O3-0.37La Al O3(简称63ST-37LA)微波介质陶瓷结构与性能的影响。结果表明:Ca O的引入未改变63ST-37LA陶瓷的晶相组成,Ca2+进入A位与主晶相形成固溶体,降低容限因子,提高介电性能;适量掺杂Ca O不仅可有效的降低烧结温度,促进晶粒生长,而且可减少晶界及晶界带来的缺陷。当Ca O的添加量为0.25wt%,在1450℃烧结时,63ST-37LA陶瓷获得最佳综合微波介电性能:εr=45.52,Q·f=52857 GHz,τf=+2.5×10-6/℃。

The effects of Ca O additive on the structure and properties of 63ST-37 LA microwave dielectric ceramics prepared by conventional solid-state route were investigated. The results show that the addition of Ca O does not change the crystal phase of 63ST-37 LA ceramics; Ca2 ＋enters into A site and the main crystal phase forms perovskite solid solution,which decreases the tolerance factor and improves the dielectric properties; moderate addition of Ca O can not only effectively lower the sintering temperature and promote grain growth,but also reduce grain boundary and the defects of them. The 0. 25wt% Ca Odoped 63ST-37 LA ceramics sintered at 1450 ℃ have the optimal integrated microwave dielectric properties ： εr= 45. 52,Q·f = 52857 GHz,τf= ＋ 2. 5 × 10- 6/ ℃.