Effect of Co2+ ions on the ligand field, optical, and structural properties of ZnLiB glasses

Glass systems with composition x CoO-(25-x) ZnO-75 Li2B4O7, (where x = 0, 0.5, 1, 2 and 3 mol%) were prepared by conventional melt-quenching technique. The density and molar volume of the glass systems were determined in order to study their structures. The physical parameters such as ionic concentration, interionic distance, polaron radius, field strength, molar refractivity, and metallization were estimated. The decrease in the optical basicity Ʌth suggests that the covalence of the glass increases. The crystal field (10Dq) and interelectronic repulsion (B, C) parameters were evaluated. FT-IR spectra of the glasses showed vibration modes corresponding to stretching of BO3 and BO4 units. It was found that N4 decreases with increasing the CoO content. This is due to the increased intensity of the vibrational bands associated to BO3 units at the expense of the BO4 units, which led to an increased number of NBOs.