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

Abstract High-quality x[(Mg 0.6 Zn 0.4 ) 0.95 Co 0.05 ] 2 TiO 4 -(1-x)Ca 0.8 Sm 0.4/3 TiO 3 ceramics were prepared by solid-state reaction. [(Mg 0.6 Zn 0.4 ) 0.95 Co 0.05 ] 2 TiO 4 has a dielectric constant (e r ) of ~18, a high quality factor (Q×f) of ~206,000 GHz, and a temperature coefficient of resonant frequency (τ f ) of ~−20.8 ppm/°C. To produce a temperature-stable material, Ca 0.8 Sm 0.4/3 TiO 3 , which has a large positive τ f value of +400 ppm/°C, was added to [(Mg 0.6 Zn 0.4 ) 0.95 Co 0.05 ] 2 TiO 4 . 0.93[(Mg 0.6 Zn 0.4 ) 0.95 Co 0.05 ] 2 TiO 4 −0.07 Ca 0.8 Sm 0.4/3 TiO 3 has an excellent combination of microwave dielectric properties: e r ~18.24, Q×f ~150,000 (at 9 GHz), and τ f ~1 ppm/°C sinters at 1175 °C, and can be utilized in the fabrication of microwave devices.