Journal of Physical Chemistry B, Vol.119, No.10, 4093-4098, 2015
Raman Response of Network Modifier Cations in Alumino-Silicate Glasses
Raman scattering is performed in three sets of aluminosilicate glasses with light cations and concentrations varying from peralcaline to peralurninate domain. The depolarized spectra highlight two,cation modes below similar to 400 cm(-1). Comparison with infrared data reveals very stringent selection rules providing as much additional information for a vibrational analysis. The latter Suggests in-phase,(network-coupled) and out-of-phase (network-decoupled) displacements of the cations relative to their adjacent negatively charged stuctures. The low frequency vibration involves all cations whatever their role in the glass, network modifiers or charge compensators. Very interestingly, the second mode originates mostly from cations at modifier's places, providing thereby a new support for structural and chemical analysis of silicate glasses using Raman scattering.