Effects of Replacing Co2+ with Zn2+ on the Dielectric Properties of Ba [Zn1/3(Nb1/2Ta1/2)2/3]O3 Ceramics with High Dielectric Constant and High Quality Factor

In this study, we used solid-state synthesis to prepare Ba[(ZnxCo1−x)1/3(Nb0.5Ta0.5)2/3]O3microwave ceramics for mobile communications. Compared with Ba[Zn1/3(Nb0.5Ta0.5)2/3]O3, in the prepared materials, Co2+substitution with Zn2+improved the Q × f value and enabled densification and sintering at a lower temperature. We used X-ray diffraction (XRD) and scanning electron microscopy (SEM) to analyze the obtained microstructure. Ba[(ZnxCo1−x)1/3(Nb0.5Ta0.5)2/3]O3was found to have a 1:2 ordered hexagonal structure, and its Q × f value increased with the increase in sintering temperature. In this work, excellent microwave dielectric properties—τf= −0.7 ppm/°C, εr= 34.5, and Q × f = 110,000 GHz—were obtained by sintering Ba[(Zn0.3Co0.7)1/3(Nb0.5Ta0.5)2/3]O3at 1400 °C for 5 h.