Effect of heterovalent ion doping on the polarization ability and dielectric loss of fluorite Ce1-xYxO1-x/2 ceramics in the microwave frequency band

Abstract

Fluorite-structured Ce1-xYxO1-x/2 (x = 0, 0.1, 0.3, 0.5) ceramics were prepared by the solid-phase reaction method. The XRD analysis reveals that the maximum solid solubility of Y3+ in CeO2 is less than 60%. With increasing x, the εr decreased from 24.02 to 18.87, and the τf decreased from −50.0 ppm/°C to −66.7 ppm/°C. The largest Q × f value of 75,661 GHz is obtained at x = 0.3. The decrease in εr is due to the reduction of ionic polarizability per unit volume and the weakening of the cationic rattling effect. The existence of Ce3+ and the rattling effect of Ce4+ are the reasons for εr being larger than εr(C-M) in Ce1-xYxO1-x/2 ceramics. The trends of τf and εr values are similar and consistent with the ion polarizability dilution mechanism. The Q × f of Ce1-xYxO1-x/2 ceramics is related to lattice energy, FWHM, and oxygen vacancy concentration.