VERY LOW-FREQUENCY LIGHT-SCATTERING IN GLASS MATRIX

Room-temperature Raman scattering spectra of glasses of the types: (SiO2) (Al2O3), (SiO2)(Ga2O3), (GeO2) (Al2O3), and (GeO2)(Ga2O3) have been collected. The low frequency band at about 50 cm-1 appears to be a common property of all analysed glasses. Changes in the optical Raman modes region were accompanied by the modification of the spectral shape in the acoustic Raman modes region. The differencies in the spectral distribution of the light scattering excess in the acoustic Raman modes region (the so called boson peak) have been interpreted in terms of changes in the microstructure of the amorphous matrix.