Low temperature sintering and microwave dielectric properties of 0.6Ba(Co1/3Nb2/3)O3–0.4Ba(Ni1/3Nb2/3)O3 ceramics using copper additions

The dielectric properties and the microstructures of 0.6Ba(Co1/3Nb2/3)O3–0.4Ba(Ni1/3Nb2/3)O3 ceramics with CuO additions (0.25–1 wt%) prepared with conventional solid-state route have been investigated. It is found that 0.6Ba(Co1/3Nb2/3)O3–0.4Ba(Ni1/3Nb2/3)O3 ceramics can be sintered at 1270 °C due to the sintering aid of CuO addition. At 1270 °C, 0.6Ba(Co1/3Nb2/3)O3–0.4Ba(Ni1/3Nb2/3)O3 ceramics with 0.5 wt% CuO addition possesses a dielectric constant (ɛr) of 32.5, a Q × f value of 82,000 (9 GHz) and a temperature coefficients of resonant frequency (τf) of −21.2 ppm/°C. The CuO-doped 0.6Ba(Co1/3Nb2/3)O3–0.4Ba(Ni1/3Nb2/3)O3 ceramics can find applications in microwave devices requiring low sintering temperature.