A New Low-loss Niobate-based Microwave Dielectric Ceramic GaNbO4

Abstract

In this work, the GaNbO4 microwave dielectric ceramics were studied for the first time. Ceramic samples were obtained via solid-state reaction method and could be sintered well in the temperature range of 1000°C–1080°C. Preparation, phase structure, grain morphology and microwave dielectric properties of GaNbO4 were investigated. It showed a novel microstructure that two allotropic GaNbO4 phases with different average grain sizes were coexisted in the GaNbO4 ceramics. The GaNbO4 sintered at 1060°C exhibited the excellent low-loss microwave dielectric properties of εr = 15.6, Q×f = 98,800 GHz (at 9.2 GHz), τf = -69.4 ppm/°C.