Dielectric properties of copper oxide doped 0.95Ba(Zn1/3Ta2/3)O3–0.05BaZrO3 ceramics at microwave frequency

The microwave dielectric properties of conventional solid state route prepared 0.95Ba(Zn1/3Ta2/3)O3–0.05BaZrO3 ceramics with CuO addition have been investigated. Ordering structure was not observed at sintering temperatures 1280–1430 °C. Copper oxide, as a sintering aid, was found to effectively lower the sintering temperature of 0.95Ba(Zn1/3Ta2/3)O3–0.05BaZrO3 ceramics. The Q × f values of 58 000–93 000 (at 7 GHz) can be obtained when the sintering temperatures are in the range of 1280–1430 °C. The permittivity (ɛr) as well as the temperature coefficient of resonant frequency τf was strongly correlated to the CuO content but independent of the sintering temperature. The ɛr value of 29.6, Q × f value of 93 000 (at 7 GHz) and τf value of 3.1 ppm °C−1 were obtained for 0.95Ba(Zn1/3Ta2/3)O3–0.05BaZrO3 ceramics with 1 wt.% CuO addition sintered at 1430 °C for 4 h. For applications of high selective microwave ceramic resonator and filter, 0.95Ba(Zn1/3Ta2/3)O3–0.05BaZrO3 is proposed as a suitable material candidate.