The structure and properties of 0.95MgTiO3–0.05CaTiO3 ceramics doped with Co2O3

Abstract

The effects of Co2O3 addition on the sintering behavior, phase formation, microstructure and microwave dielectric properties of 0.95MgTiO3–0.05CaTiO3 ceramics have been investigated. The structure and microstructure of the ceramics were investigated using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. These results suggested that Co2O3 addition not only contributes in lowering the sintering temperature but also inhibits the formation of second phase MgTi2O5 in 0.95MgTiO3–0.05CaTiO3 ceramics. Moreover, the decomposition of Co2O3 would inhibit the Ti4+ from being restored to Ti3+, which had the positive effect on the Q × f value. A fine combination of microwave dielectric properties (e r = 20.48, Q × f = 76,485 GHz, τ f = 2.43 ppm/°C) was achieved for 0.95MgTiO3–0.05CaTiO3–0.01Co2O3 ceramics sintered at 1300 °C for 4 h, which satisfied microwave applications in resonators, filters and antenna substrates.