Studies on Bonding Mode of Al Atoms in K₂O-AlF₃-B₂O₃ Glasses Based on Optical Absorption of VO²⁺ and AlK_α X-ray Emission Spectra

Abstract

The glass forming region in the system K₂O-AlF₃-B₂O₃ has been determined. The measurements of optical absorption spectra of VO²⁺ ions dissolved in the system glasses and AlK_α X-ray emission spectra of 0.25K₂O⋅0.15 AlF₃⋅0.60B₂O₃ and 0.25K₂O⋅0.20AlF₃⋅0.55B₂O₃ glasses have been made. In the light of these spectral results obtained, the bonding mode of Al atoms in the glasses has been discussed. Two modes have been suggested to be considered. In a mode, the only K⁺[K⁺AlO₃F₃^-]^- group is formed and, in the other, K⁺[K⁺(O₃B-O-AlF₃)^-]^- or K⁺[K⁺(O₃Al-O-BF₃)^-]^- group is formed together with the K⁺[K⁺AlO₃F₃^-]^- in arbitrary ratios.