Effects of Y2O3 substitution on microwave dielectric properties of Ba(Co0.6Zn0.38)1/3Nb2/3O3 ceramics

The effects of Y2O3 substitution on the microstructure and microwave dielectric properties of Ba(Co0.6−xYxZn0.38)1/3Nb2/3O3 (x = 0–0.06) ceramics prepared by the conventional solid-state route technique were investigated. The X-ray diffraction results presented that all the well sintered samples exhibited the main phase BaZn0.33Nb0.67O3–Ba3CoNb2O9 and a certain amount of Ba8CoNb6O24 second phase. The 1:2 B-site cation ordering degree was found to influenced by the replacement of Y3+, especially for x = 0.02. Then the scanning electron microscopy pictures of the optimally well-sintered (1375 °C for 20 h) ceramics has shown a dense microstructure. Although the εr almost kept unchanged, appropriate doping content would greatly improve the Q × f value. Meanwhile, the τf value increased slightly with increasing x. At last, the excellent microwave dielectric properties of εr = 35.21, Q × f = 72,046 GHz, τf = 3.65 ppm/°C were obtained for x = 0.02 sintered in air at 1375 °C for 20 h.