Effect of V2O5 and CuO additives on sintering behavior and microwave dielectric properties of BiNbO4 ceramics

The influences of V2O5 and CuO additives on the sintering behavior and micr owave dielectric properties of BiNbO4 ceramics were investigated. The V2O5 and CuO additives lowered the sintering temperature of BiNbO4 ceramics to t he range 875 degrees C-935 degrees C. All BiNbO4 compounds with additives h ad the orthorhombic structure. The dielectric constant epsilon(r) was not s ignificantly changed, while the unloaded Q value was affected with additive s. The Qf value was found to be a function of the sintering temperatures an d the amount of additives. It varied from 4500 to 15800 (GHz) and 1000 to 8 000 (GHz) with additives V2O5 and CuO, respectively. The tau(f) values were increased in positive values with V2O5 doped, while decreased in negative values with CuO addition. V2O5 and CuO additives effectively improved the d ensification and dielectric properties of BiNbO4 ceramics. The correlation between the microstructure and the Qf value was observed with different add itives. (C) 2000 Kluwer Academic Publishers.