Microwave dielectric properties of two low temperature sintering ceramics in the PbO–WO3 binary system

Abstract Two microwave dielectric ceramics in the PbO–WO 3 binary system, PbWO 4 and Pb 2 WO 5 , with low sintering temperatures were prepared by a conventional solid-state reaction method. The Pb 2 WO 5 ceramic could be well densified at around 520 °C and demonstrated high performance microwave dielectric properties with a relative permittivity ~16.4, a Q × f value ~14,805 GHz (at 7.6 GHz), and a negative temperature coefficient of resonant frequency ~ −94.5 ppm/°C. The PbWO 4 ceramic could be well densified at around 620 °C with a larger relative permittivity ~21.4, a higher Q × f value ~43,000 GHz (at 7.0 GHz), and a nearly zero temperature coefficient of resonant frequency ~ −7.1 ppm/°C. From the X-ray diffraction pattern, backscattered electron image and energy dispersive spectrometer analysis results of the co-fired samples with 20 wt% Ag or Al additive, the PbWO 4 and Pb 2 WO 5 ceramics did not react with either Ag or Al powders at their optimum sintering temperature.