Optical Absorption Spectra of Cu²⁺ Ions in PbO-SiO₂-CuO and PbO-SiO₂-K₂O-Na₂O-CuO Glasses and Refractive Index of These Glasses

Abstract

Absorption spectra of Cu²⁺ ions in PbO-SiO₂-CuO and PbO-SiO₂-K₂O-Na₂O-CuO glasses were measured, and the relation between composition and absorption peak wave number of Cu²⁺ was studied. The peak position shifted toward the higher wave numbers with increasing [PbO]/[SiO₂] ratio in PbO-SiO₂-CuO glasses. The mixed alkali effect given to the peak wave number in PbO-SiO₂-K₂O-Na₂O-CuO glasses depended on the [PbO]/[SiO₂] ratio. The peak position at [PbO]/[SiO₂]=0.64 shifted toward the lower wave numbers with increasing [K₂O]/[K₂O+Na₂O] ratio. The peak position at [PbO]/[SiO₂]=1.0 also shifted toward the lower wave numbers with increasing [K₂O]/[K₂O+Na₂O] ratio and the minimum was found at [K₂O]/[K₂O+Na₂O]≈0.7. At [PbO]/[SiO₂]=1.5, the minimum was found at [K₂O]/[K₂O+Na₂O]≈0.35. The mixed alkali effect was most distinct at this ratio. The relation between glass composition and refractive index in PbO-SiO₂-K₂O-Na₂O-CuO glasses was studied. No mixed alkali effect was found in the refractive index. The refractive index shifted linearly toward the lower values with increasing [K₂O]/[K₂O+Na₂O] ratio.