Influence of Sb2O3-ZnO additives on sintering characteristics and dielectric properties of (Mg0.95Ca0.05)TiO3 microwave ceramics

Abstract The influence of Sb2O3-ZnO additives on the phase composition, microstructure and dielectric properties of (Mg0.95Ca0.05)TiO3 microwave dielectric ceramics (95MCT), synthesized by the conventional method of solid-state reaction, was studied. X-ray diffraction patterns revealed that the formation of the second-phase of MgTi2O5, which adversely impacted the microwave dielectric properties, could be effectively restrained by the addition of Sb2O3 and ZnO. Furthermore, addition of an appropriate amount of Sb2O3-ZnO could not only lower the sintering temperature from 1400 to 1300 °C, but also improve the dielectric properties and promote homogenization of grain size. The experimental results indicated that co-doping 95MCT with 1.0 wt% Sb2O3 and 1.0 wt% ZnO broadened the sintering range by 40 °C. When sintered at 1300 °C for 2 h, the co-doped 95MCT ceramics exhibited the best microwave dielectric properties: er = 20.56, Q × f = 64700 GHz (f = 7 GHz), and τf = −2.24 ppm °C−1.