A new series of low-temperature cofirable Li3Ba2La3(1-x)Y3x(MoO4)8 microwave dielectric ceramics

A new series of Li3Ba2La3(1-x)Y3x(MoO4)8 microwave dielectric ceramics were prepared by a conventional solid-state reaction method. The Rietveld refinement results further confirm that Li3Ba2La3(1-x)Y3x(MoO4)8 belongs to a monoclinic system with space group C2/c. Scanning electron microscopy results reveal that Li3Ba2La3(1-x)Y3x(MoO4)8 ceramics can be well sintered at a low sintering temperature. In addition, the permittivity (εr) of Li3Ba2La3(1-x)Y3x(MoO4)8 ceramics was found to decrease gradually with increasing substitution content of Y3+, while the quality factor (Qxf) and temperature coefficient of resonant frequency (τf) increase with x monotonously. The x = 0.4 ceramic sintered at 700 °C for 4 h possesses optimum microwave dielectric properties of εr ∼ 14.4, Qxf ∼ 14,994 GHz (at 9.0 GHz) and τf ∼ + 6.9 ppm/°C. Particularly, no chemical reaction between the matrix phase and Ag metal suggests that the Li3Ba2La1.8Y1.2(MoO4)8 ceramic might be a promising candidate for low-temperature co-fired ceramic applications.