Light scattering spectra of fast relaxation in silica and Ca0.4K0.6(NO3)(1.4) glasses - art. no. 064207

Light-scattering spectra of two glasses, Ca0.4K0.6(NO3)(1.4) and silica are measured in the frequency range 1-10 000 GHz, covering temperatures from 1 9 K to 310 K. The low-frequency wing of the fast-relaxation spectrum is fou nd to show a power-law behavior with an exponent a proportional to temperat ure at values alpha <0.7. The data are qualitatively and quantitatively com pared to different models on relaxations in glasses. It is shown that a mod el of thermally activated transitions in double-well potentials well descri bes the fast-relaxation spectra in both materials.