Liquid phase sintering of (Zr,Sn)TiO4 microwave dielectric ceramics

Abstract The effect of CuO addition on the microstructures and the microwave dielectric properties of (Zr 0.8 ,Sn 0.2 )TiO 4 ceramics have been investigated. It is found that low-level doping of ZnO (1 wt%) and CuO (up to 2 wt%) can significantly improve the density and dielectric properties of (Zr 0.8 ,Sn 0.2 )TiO 4 ceramics. (Zr 0.8 ,Sn 0.2 )TiO 4 ceramics with additives could be sintered to a theoretical density higher than 96% at 1220°C, due to the liquid phase effect of CuO addition, as observed by scanning electron microscopy (SEM). A secondary phase was not observed at the level of 0.5–2 wt% CuO addition. The dielectric constant (e r ). While the temperature coefficient of resonant frequency (τ f ) were not significantly affected, the unloaded quality factors Q were effectively promoted by CuO addition. An e r value of 38, Q· f value of 50000 (at 7 GHz), and τ f value of 3 ppm/°C were obtained for 1 wt% ZnO doped (Zr 0.8 ,Sn 0.2 )TiO 4 ceramics with 1 wt% CuO addition sintered at 1220°C.