Study of CuO and V2O5 Effect on IR Spectra of Polycrystalline Bismuth Niobate

Bismuth niobate (BiNbO₄) ceramics were fabricated by mixed oxide method and sintered by presureless sintering method. BiNbO₄ ceramics doped with V₂ O₅ additive in amount 0.125 wt%, 0.250 wt% and 1 wt% of was sintered at T = 910°C whereas BiNbO₄ ceramics doped with 2 wt% of CuO additive was sintered at T = 890°C and T = 910°C. It was found that V₂ O₅ additive improved morphology of the ceramic samples. However, the chemical composition of BiNbO₄ ceramics in relation to bismuth oxide and niobium oxide manifested a tendency of lack of Bi₂ O₃ component. Absorption bands for the BiNbO₄ compound were identified. FTIR band positions associated with NbO₆ octahedra suggested that the crystal structure changes after V₂ O₅ incorporation.