Phase relation and microwave dielectric properties of xCaTiO3–(1 − x)TiO2–3ZnTiO3 multiphase ceramics

Microwave dielectric ceramics of xCaTiO3–(1 − x)TiO2–3ZnTiO3 (x = 0.05–1.00) were prepared by the solid-state reaction method. The phase relations were investigated using X-ray powder diffraction. In all the studied range, the sintered ceramic was multiphase, which was also verified by scanning electron microscopy (SEM) observation, as well as the energy-dispersive X-ray spectroscopy (EDX) analysis. With the increase of x from 0.05 to 0.25, the amount of rutile phase decreases due to the formation of new Ca2Zn4Ti16O38 polytitanates. And with x increasing from 0.25 to 1.00, rutile phase disappears while CaTiO3 phase increases, accompanying with a slight decrease of Ca2Zn4Ti16O38. Thus, it is considered that the preferential chemical reaction in the system enhanced the formation of the Ca2Zn4Ti6O38 compound, CaTiO3 and rutile phases in the ceramics. Moreover, the microwave dielectric properties of the ceramics were investigated. The simulated dielectric properties of the ceramics were also calculated based on the empirical model. The simulated results and the experimental ones have similar trends, which show that the change of microwave dielectric properties is related to the change of the phase composition in the multiphase ceramics.