Structures and dielectric properties of a new dielectric material system xMgTiO3–(1−x)MgTa2O6 at microwave frequency

Crystal structure and the microwave dielectric properties of xMgTiO3–(1−x)MgTa2O6 sintered specimens with x = 0.3, 0.5, 0.7 are investigated. The X-ray diffraction patterns revealed the sintered specimens are mixed phases of MgTiO3, MgTa2O6 and MgTi2O5. The microwave dielectric properties are strongly correlated with the sintering temperature and the composition. With x = 0.7, a new microwave dielectric ceramic material 0.7MgTiO3–0.3MgTa2O6 at 1460 °C for 3 h is suggested for microwave device and it possesses excellent dielectric properties; a dielectric constant ɛr ∼ 23, a Q × f value ∼81,000 GHz and a τf value ∼−2 ppm/°C. The correlation between microwave dielectric properties and the microstructures is also discussed.