Mg(Ti0.95Sn0.05)O3–(Ca0.8Sr0.2)TiO3 ceramics: Phase, microstructure, and microwave dielectric properties

Abstract The phase, microstructure, and microwave dielectric properties of (1 − x)Mg(Ti0.95Sn0.05)O3–x(Ca0.8Sr0.2)TiO3 (0.01 ≤ x ≤ 0.07) ceramics were investigated. (Ca0.8Sr0.2)TiO3 was used as a τf compensator and was added to Mg(Ti0.95Sn0.05)O3 to obtain a temperature-stable material. The powder X-ray diffraction patterns suggest the presence of Mg(Ti0.95Sn0.05)O3 as the main crystalline phase and Ca0.8Sr0.2TiO3 and MgTi2O5 as the minor phases. With increasing (Ca0.8Sr0.2)TiO3 content, the dielectric constant er and the temperature coefficient of the resonant frequency τf of the ceramics increases, whereas the unloaded quality factor Qufo decreases. For 0.95[Mg(Ti0.95Sn0.05)O3]–0.05(Ca0.8Sr0.2)TiO3 ceramics sintered at 1375 °C, the dielectric constant er (21.1), the quality factor Qufo (117,000) at 9 GHz, and the temperature coefficient of the resonant frequency τf (−1.79 ppm/°C) were obtained.