Microwave dielectric properties and phase evolution of Zn-excess Mg_0.95Zn_0.05+xTiO_3+x (x = 0–0.1) ceramics

The rapid development of 5G and 6G technologies has led to an increased demand for microwave dielectrics ceramics. Microwave dielectrics ceramics with high Q value and low cost have attracted a lot of attention from researchers. Such as material sintered at relatively low temperature and cheap raw materials. Magnesium titanate (MgTiO₃) is a material with excellent dielectric properties but requires high-temperature sintering. It is reported that substitution of Zn²⁺ for Mg²⁺ can lower sintering temperature and improve dielectric properties. Here, microwave dielectric properties and phase evolution of Zn-excess Mg_0.95Zn_0.05+xTiO_3+x (x = 0, 0.025, 0.05, 0.075, 0.1) compositions were investigated. A moderate Zn-excess is found to promote formation of pure MgTiO₃ phase with lower temperature. The composition with x = 0.05 sintered at 1300 °C possess optimal dielectric performance ε_r of 17.85, Q × f of 173,300 GHz (@11 GHz) and τ_f of − 52.04 ppm/°C with relative density of 97%.