Microstructures and Dielectric Properties of Ba1−xSrxTiO3 Ceramics Doped with B2O3-Li2O Glasses for LTCC Technology Applications

Ba1−xSrxTiO3 ceramics, doped with B2O3-Li2O glasses have been fabricated via a traditional ceramic process at a low sintering temperature of 900 °C using liquid-phase sintering aids. The microstructures and dielectric properties of B2O3-Li2O glasses doped Ba1−xSrxTiO3 ceramics have been investigated systematically. The temperature dependence dielectric constant and loss reveals that B2O3-Li2O glasses doped Ba1−xSrxTiO3 ceramics have diffusion phase transformation characteristics. For 5 wt% B2O3-Li2O glasses doped Ba0.55Sr0.45TiO3 composites, the tunability is 15.4% under a dc-applied electric field of 30 kV/cm at 10 kHz; the dielectric loss can be controlled about 0.0025; and the Q value is 286. These composite ceramics sintered at low temperature with suitable dielectric constant, low dielectric loss, relatively high tunability and high Q value are promising candidates for multilayer low-temperature co-fired ceramics (LTCC) and potential microwave tunable devices applications.