Microstructures and microwave dielectric properties of Li2O–Nb2O5–ZrO2 ceramics

Solid solution of Li1−4y−xZry+4xNb1−3xO3 system is a new non-stoichiometric compound with orthorhombic perovskite structure. In this study, the effects of the calcination and the sintering temperatures on the microstructural evolution and microwave dielectric properties of Li1−4y−xZry+4xNb1−3xO3 ceramics were performed. Dense Li0.774Zr0.057NbO3 ceramics can be obtained at the sintering temperature of 1150 °C. Li0.774Zr0.057NbO3 phase exists as the main phase with the existence of a minor LiNb3O8 phase. Typical microwave dielectric properties for dense Li0.774Zr0.057NbO3 ceramics are as followed: ɛr ≈ 39, Q × f ≈ 4500, and τf = −16.6 ppm/°C, measured at 6 GHz.