Effect of V2O5 on the sintering behaviour, cation order and properties of Ba3Co0.7Zn0.3Nb2O9 ceramics

The microstructures and microwave dielectric properties of barium cobalt zinc niobate ceramics prepared by conventional mixed oxide route have been investigated. It was found that low level doping of V2O5 (up to 0.2 wt.%) could significantly improve densification of the specimens and their microwave dielectric properties. Dielectric properties of V2O5 doped samples were affected by 1:2 ordering in the B-site. Slow cooling after sintering or annealing in nitrogen atmosphere improved the unloaded quality factor (Q.f values) significantly. The Ba3Co0.7Zn0.3Nb2O9 (BCZN) ceramics exhibited ɛr = 34.5, τf = 0 ppm/C and Q.f = 85,000 at 4 GHz.