Crystal structure and microwave dielectric properties of [(Mg0.6Zn0.4)0.95Co0.05]2TiO4 modified Ca0.8Sm0.4/3TiO3 ceramics

High-quality x[(Mg0.6Zn0.4)0.95Co0.05]2TiO4-(1-x)Ca0.8Sm0.4/3TiO3 ceramics were prepared by solid-state reaction. [(Mg0.6Zn0.4)0.95Co0.05]2TiO4 has a dielectric constant (εr) of ~18, a high quality factor (Q×f) of ~206,000 GHz, and a temperature coefficient of resonant frequency (τf) of ~−20.8 ppm/°C. To produce a temperature-stable material, Ca0.8Sm0.4/3TiO3, which has a large positive τf value of +400 ppm/°C, was added to [(Mg0.6Zn0.4)0.95Co0.05]2TiO4. 0.93[(Mg0.6Zn0.4)0.95Co0.05]2TiO4 −0.07 Ca0.8Sm0.4/3TiO3 has an excellent combination of microwave dielectric properties: εr~18.24, Q×f ~150,000 (at 9 GHz), and τf ~1 ppm/°C sinters at 1175 °C, and can be utilized in the fabrication of microwave devices.