Multi-site effect in the IR spectra of various inorganic glasses: experimental evidence and structural reasons

Abstract

Data on the IR spectra of various glasses are reviewed and the spectra of glasses such as vitreous barium metaphosphate, alkali zinc pyrophosphate glasses, and binary borate glasses are subjected to an additional quantitative treatment. A multi-band pattern in the range of the asymmetric stretching modes is shown to occur in the spectra of these glasses. The main reason for the splitting of the asymmetric stretching modes of basic structural groups is shown to be a multi-site effect due to the occurrence of two or more translationally non-equivalent positions of structural groups in the regions of phonon localization. Investigation of the relative intensities of the spectral components originated from the same stretching mode as a function of glass composition is suggested as a possible tool for the study of subtle features of glass structures.