Sintering behavior and microwave dielectric characteristics of BaO–Sm2O3–4TiO2 ceramics with B2O3 and BaB2O4 addition

We studied the low temperature sintering and the reaction in BaO–Sm2O3–4TiO2 ceramics with boron-based additives for the application to microwave dielectric devices. The amount of the boride glasses of B2O3 and BaB2O4 was varied from 1 to 10 wt.% and the green compacts were sintered in the temperature range of 900–1200 °C for 2 h. When B2O3 was added, second phases of Sm2Ti2O7, BaTi(BO3)2, Ba2Ti9O20, and TiO2 were formed, while BaB2O4 addition resulted in the formation of BaSm2Ti4O12 single phase without second phases. On the basis of these results, it is regarded that the B2O3 is a reactive glass and the BaB2O4 is a non-reactive glass. The second-phase development, sintering behavior and microwave dielectric characteristics of BaO–Sm2O3–4TiO2 ceramics were examined.