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

Novel monoclinic Bi 2 O 3 -xRE 2 O 3 -yMoO 3 (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 Bi 2 O 3 -xRE 2 O 3 -yMoO 3 ceramics are investigated. Dense BiNdMoO 6 ceramics sintered at 900   °C for 8   h in air have a low dielectric constant ε r =~7.5, a high quality factor Q × f =~ 24, 800   GHz at 7.0   GHz, and τ f =~−16   ppm/̊C. Especially, good chemical compatibility of BiNdMoO 6 with Ag electrodes is represented as well. In contrast, BiSmMoO 6 ceramics sintered at 1000   °C for 8   h show enhanced Q×f =~43, 700   GHz at 7.8   GHz with ε r = ~8.5 and τ f = ~−27   ppm/°C. Bi 2 O 3 -xRE 2 O 3 -yMoO 3 (RE=Pr, Nd, Sm, and Yb) based ceramics could be considered as promising microwave ceramics for LTCC applications.