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

Solid solution of Li 1−4 y − x Zr y +4 x Nb 1−3 x O 3 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 Li 1−4 y − x Zr y +4 x Nb 1−3 x O 3 ceramics were performed. Dense Li 0.774 Zr 0.057 NbO 3 ceramics can be obtained at the sintering temperature of 1150 °C. Li 0.774 Zr 0.057 NbO 3 phase exists as the main phase with the existence of a minor LiNb 3 O 8 phase. Typical microwave dielectric properties for dense Li 0.774 Zr 0.057 NbO 3 ceramics are as followed: ɛ r ≈ 39, Q × f ≈ 4500, and τ f = −16.6 ppm/°C, measured at 6 GHz.