Sintering behavior and microwave dielectric properties of Sr2CeO4 ceramics doped with Li2CO3-Bi2O3

Microwave dielectric ceramics Sr 2 CeO 4  +  n wt% Li 2 CO 3 —Bi 2 O 3 (LB) (1 ≤  n  ≤ 4, L: B =  x : y , weight ratio) were prepared by a traditional solid-state reaction method. The effects of LB additives on the phase formation, microstructure, sintering behavior, and microwave dielectric properties of Sr 2 CeO 4 ceramics were investigated. The sintering temperature can be reduced obviously from 1270 to 950 °C because of the liquid phase formation of LB. Single-phase Sr 2 CeO 4 ceramics with dense structure and homogenous grains were obtained by adding 1wt% LB. With LB content increasing, Q × f values would decrease because secondary-phase SrCeO 3 appeared in the ceramics. When the content of LB was fixed at 1 wt%, the sintering temperature and Q × f value would decrease simultaneously with the ratio of Li 2 CO 3 increasing. Desirable performances of Sr 2 CeO 4  + 1wt% LB ceramics: ( ε r  = 14.36, Q × f = 102,023 GHz and τ f  =  − 66.42 ppm/°C, L:B = 2:8) and ( ε r  = 13.56, Q × f = 70,109 GHz, τ f  =  − 64.17 ppm/°C, L:B = 8:2) can be achieved at 1075 °C and 950 °C, respectively, suggesting that Sr 2 CeO 4 –LB ceramics have a great potential for millimeter-wave applications.