Infrared spectroscopy and microwave dielectric properties of ultra-low temperature firing (K_0.5La_0.5)MoO₄ ceramics

The (K_0.5La_0.5)MoO₄ ceramics with intrinsic ultra-low sintering temperature were prepared via the solid state reaction method. Pure monoclinic (K_0.5La_0.5)MoO ₄ phase was formed at around 660 °C. High performance of microwave dielectric properties were obtained in ceramic sample sintered at 680 °C with a permittivity of ∼10.3, a temperature coefficient of resonant frequency about -81 ppm/°C, and Qf value of 59,000 GHz. Complex dielectric spectra gained from the infrared spectra were extrapolated down to microwave range, and they were in good agreement with the measured microwave permittivity and dielectric losses. The novel (K_0.5La_0.5)MoO ₄ ceramic might be a good candidate for microwave devices application.