Borate glass structure by Raman and infrared spectroscopies

Article abstract of DOI:10.1016/0022-2860(91)87058-P

Raman and infrared spectroscopies have been employed to probe the continuous evolution of borate glass structures as a function of the nature and concentration of alkali oxide modifiers.At relatively low alkali contents, the glasses contain covalent networks consisting of interconnected units bearing BO4^- tetrahedra.Further addition of alkali oxide causes the progressive depolymerization of the network as a result of the formation of non-bridging oxygen atoms.Eventually, complete network disruption into small and highly charged borate units results in ionic glasses.The nature of the alkali cation determines the structure of these glasses by affecting several high-temperature isomerization or disproportionation equilibria.