Structure and dielectric properties of novel low temperature co-fired Bi2O3-RE2O3-MoO3 (RE=Pr, Nd, Sm, and Yb) based microwave ceramics

Novel monoclinic Bi2O3-xRE2O3-yMoO3 (RE=Pr, Nd, Sm, and Yb) based low temperature co-fired ceramics (LTCC) systems with high sintering density and low microwave dielectric loss are synthesized by conventional solid state reaction technique. The structure and dielectric properties of Bi2O3-xRE2O3-yMoO3 ceramics are investigated. Dense BiNdMoO6 ceramics sintered at 900 °C for 8 h in air have a low dielectric constant εr=~7.5, a high quality factor Q×f=~ 24, 800 GHz at 7.0 GHz, and τf=~−16 ppm/̊C. Especially, good chemical compatibility of BiNdMoO6 with Ag electrodes is represented as well. In contrast, BiSmMoO6 ceramics sintered at 1000 °C for 8 h show enhanced Q×f=~43, 700 GHz at 7.8 GHz with εr=~8.5 and τf=~−27 ppm/°C. Bi2O3-xRE2O3-yMoO3 (RE=Pr, Nd, Sm, and Yb) based ceramics could be considered as promising microwave ceramics for LTCC applications.