Anomalies in the forced Rayleigh scattering in glasses

Two glasses were investigated between 300 and 6 K, by means of forces Rayleigh scattering. Below approximately 50 K, unexpectedly strong scattering was observed. The source of the excess scattering is in local thermal equilibrium with the phonon bath above 20 K. A crossover to local relaxation is found below. © 1979 The American Physical Society.