MnCO_3掺杂对Ba_4Sm_(9.33)Ti_(18)O_(54)微波介质陶瓷性能的影响

Effect of MnCO_3 Doping on the Properties of Ba_4Sm_(9.33)Ti_(18)O_(54) Microwave Dielectric Ceramics

采用固相反应法,研究了MnCO_3掺杂对Ba_4Sm_(9.33)Ti_(18)O_(54)(简称BST)微波介质陶瓷结构与性能的影响。结果表明:适量掺杂MnCO_3,不仅可有效的降低BST陶瓷的烧结温度至1240℃,而且能通过Mn^(3+)+Ti^(3+)→Mn^(2+)+Ti^(4+)反应,抑制Ti^(4+)被还原及第二相Sm_2Ti_2O_7出现,改善其介电性能。当MnCO_3添加量为0.10wt%,在1240℃温度烧结3 h时,BST陶瓷获得最佳的介电性能:εr=83.64,Q·f=10007 GHz,τf=0.3×10^(-6)/℃。

The effects of MnCO_3 additive on the structure and properties of Ba_4Sm_(9.33)Ti_(18)O_(54)( BST)microwave dielectric ceramics which prepared by conventional solid-state route were investigated. The results show that moderate addition of MnCO_3 could not only effectively lower the sintering temperature which dropped to 1240 ℃,but also inhibit Ti^(4+)be reduced according to the reaction: Mn^(3+)+ Ti^(3+)→Mn^(2+)+ Ti^(4+),the emergence of the Sm_2Ti_2O_7 phase,improve the dielectric properties. The 0. 10wt%MnCO_3-doped BST ceramics sintered at 1240 ℃ have the optimal integrated microwave dielectric properties: εr= 83. 64,Q·f = 10007 GHz,τf= 0. 3 × 10^(-6)/ ℃.