Influence of ZnO and Nb2O5 Additions on Sintering Behavior and Microwave Dielectric Properties of (Mg0.95Ca0.05 )TiO3 Ceramics

Abstract

The influence of ZnO and Nb2O5 additions on the sinterability, microstructure and microwave dielectric properties of (Mg0.95Ca0.05)TiO3 (abbreviated as 95MCT hereafter) ceramic is investigated. XRD patterns indicate that MgTi2O5 secondary phase can be effectively suppressed by ZnO and Nb2O5 additions, which is beneficial for improving the microwave dielectric properties. Appropriate amount of Nb2O5 addition can effectively improve the Qf value of 95MCT ceramic, which is suggested to be ascribed to the reduced oxygen vacancies. When the ZnO: Nb2O5 mole ratio is 1.5 and the co-doping content is 0.25wt%, the optimal microwave dielectric properties can be obtained Qf=72730GHz(6.8GHz), εr=20.29 and τf=-6.84ppm/°C and the sintering temperature of 95MCT is lowered from 1400°C to 1320°C.