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

Abstract

Two microwave dielectric ceramics in the PbO–WO3 binary system, PbWO4 and Pb2WO5, with low sintering temperatures were prepared by a conventional solid-state reaction method. The Pb2WO5 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 ~14,805GHz (at 7.6GHz), and a negative temperature coefficient of resonant frequency ~ −94.5ppm/°C. The PbWO4 ceramic could be well densified at around 620°C with a larger relative permittivity ~21.4, a higher Q×f value ~43,000GHz (at 7.0GHz), and a nearly zero temperature coefficient of resonant frequency ~ −7.1ppm/°C. From the X-ray diffraction pattern, backscattered electron image and energy dispersive spectrometer analysis results of the co-fired samples with 20wt% Ag or Al additive, the PbWO4 and Pb2WO5 ceramics did not react with either Ag or Al powders at their optimum sintering temperature.