Infra-red Reflection Spectra of Mixed Alkali and Alkali-Alkaline-Earth Silicate Glasses

Abstract

Relation between the peak shift in infra-red reflection spectra and the structure of mixed alkali and alkaline-earth silicate glasses was studied.
In the R₂O-R′₂O-SiO₂ systems, the main peak due to Si-O-Si bond shifted to lower wavenumbers with the substitution of smaller cations for larger ones, though the shift to opposite direction was found in the phase separable glasses. In the R₂O-RO-SiO₂ systems, the main peak shifted to the same direction as in the former system with the substitution of RO for R₂O. In the latter system, however, the replacement with larger divalent cation caused greater shift of main peak toward lower wavenumber.
The direction of peak shift was discussed from the view point of the effect of introduced cation (1) on the bonding strength of the Si-O-Si linkage (forming glass network) and (2) on the spread of the Si-O-Si linkage.