Synthesis and optical properties of Co2+ and Ni2+ ions doped β-BaB2O4 nanopowders

Co2+ and Ni2+ ions doped β-BaB2O4 nanopowders have been prepared by co-precipitation method and their structural properties are studied by spectroscopic techniques. Powder XRD data reveals that the crystal structure belongs to monoclinic and the average crystallite size is calculated. Optical absorption spectra data reveal octahedral site symmetry for Co2+ and Ni2+ ions. Crystal field (Dq) and inter-electron repulsion (B and C) parameters are evaluated for Co2+ doped β-BaB2O4 nanopowders as Dq=960, B=900 and C=3850 cm−1 and for Ni2+ doped β-BaB2O4 nanopowders, Dq=900, B=850 and C=3500 cm−1. FT-IR spectra showed the characteristic vibrational bands related to BO3 and BO4 molecules. Photoluminescence spectra contain the emission bands in ultraviolet and blue regions.