Raman Study on Glasses and Crystalline Compounds in the System K3AsO4-KAsO3

Abstract

Raman and IR spectra of the crystalline compounds α-K3AsO4 K4As2O7, K5As3O10, and γ-KAsO3 are given together with tentative assignments in terms of symmetrical and antisymmetrical As—O− and As—O—As bond-stretching and bond-bending vibrations. Comparison of the Raman spectra of crystalline arsenates with those of vitreous arsenates, stabilized with Al2O3, in the composition region KAsO3-K4As2O7 is used to deduce the molecular structure of these glasses. It appears that in the glasses chains of AsO4 tetrahedra are present.