Brillouin scattering study of inorganic glass-forming liquids

Abstract

Light scattering experiments were performed on two inorganic glass-forming liquids: ZnCl₂ and 0.8TeO₂-0.2Na₂O up to 650°C. In ZnCl₂, vertical-vertical and vertical-horizontal spectra were analysed with viscoelastic theory using either a Debye or a Cole-Davidson model for the memory function. We show that the Cole-Davidson memory function yields a consistent interpretation of all the spectra. The resulting shear and longitudinal relaxation times are equal within their error bars and are about 2.5 times smaller than the α-relaxation time previously determined. The static shear viscosity values deduced from the analysis of the propagating transverse waves agree, at all temperatures, with the measured viscosity values.