Impact of cobalt ions on the phonon energy and ligand field parameters of some borate glasses

Abstract

This paper concentrates on the optical properties of cobalt borate glasses. A glass system 62B2O3 + 18Na2O + (20-y) ZnO + (y) CoO where y = 0.5, 1.0 and 1.5 mol.% was produced by the melt-quenching method. Traditional techniques and standard formulas were used to determine the average density (ρ) and molar volume (Vm). Optical spectra were recruited, in terms of absorbance, to study the ligand field parameters in all glasses. The optical band gap (Eg) and phonon energy (Eph) showed increasing behaviors with the increment in the content of Co cations. The obtained values of 10Dq/B point to a slight increment toward the strong crystal field. The average density showed increasing behavior and molar volume showed an opposite behavior with increasing Co cations. Moreover, the structural parameters in terms of interatomic separation were employed to study the increment toward the strong crystal field with the increment in the content of Co cations.