Microstructure and microwave dielectric properties of (1 − x)Ca0.6La0.267TiO3–xCa(Mg1/3Nb2/3)O3 ceramics

(1 − x)Ca0.6La0.267TiO3–xCa(Mg1/3Nb2/3)O3 ceramics were prepared by a conventional solid-state ceramic route. The microstructure and microwave dielectric properties were investigated as a function of composition and sintering temperature. As the content of Ca(Mg1/3Nb2/3)O3 increased, the temperature coefficient of resonant frequency (τf) value decreased gradually. By appropriately adjusting the x value in the present ceramic system, a near-zero τf value could be achieved. The appropriate increase of sintering temperature could significantly improve Q·f value by influencing the grain growth. The optimal microwave dielectric properties with a dielectric constant (ɛr) of 52.4, Q·f of 36,428 GHz (at 5.8 GHz), and τf of 3.4 ppm/°C were obtained for the specimen 0.5Ca0.6La0.267TiO3–0.5Ca(Mg1/3Nb2/3)O3 sintered at 1490 °C for 4 h.