Temperature coefficient of resonant frequency tuning of microwave dielectric based on Zr substitutions for Ti on Ca0.4Sm0.4TiO3 ceramic system

Ca 0.4 Sm 0.4 (Ti 1−x Zr x )O 3 (x = 0.01–0.1) ceramics were prepared by a solid state ceramic method, and phase purity, microstructure, and microwave dielectric properties were investigated. An excess of Zr 4+ resulted in the formation of a secondary phase of Sm 2 Ti 2 O 7 , affecting the microwave dielectric properties of the Ca 0.4 Sm 0.4 (Ti 1−x Zr x )O 3 ceramics. Dielectric properties are strongly dependent on the composition, the densification and the microstructure of the samples. The Q × f value and dielectric constant decrease with an increase in x. In addition, the temperature coefficient of the resonant frequency of the Ca 0.4 Sm 0.4 (Ti 1−x Zr x )O 3 ceramics also improved with increasing Zr content. The suitable microwave dielectric properties of ε r ~78.8, Q × f ~2600 GHz, and τ f ~23 ppm/ ° C could be obtained when x = 0.1.