Sintering behavior and microwave dielectric properties of LiMVO4 (M = Mg, Zn)

Two V-containing microwave dielectric ceramics, LiMgVO4 and LiZnVO4, with excellent microwave performance were prepared by a solid-state reaction route at relatively low temperatures. Using NH4VO3 to replace V2O5 could effectively reduce the sintering temperature of LiMgVO4 and LiZnVO4 to 720 °C and enhance their microwave dielectric properties. LiMgVO4 ceramics sintered at 720 °C exhibited a permittivity ~9.89, a Q × f value of 30,800 GHz and a temperature coefficient of resonant frequency ~−171 ppm/°C. LiZnVO4 ceramics had a relatively smaller τf value of −114 ppm/°C with a εr ~ 7.48, a Q × f value of 27,600 GHz. Further efforts are in progress to search for effective approaches to compensate their large negative τf values to be near zero.