Effect of temperature on the vibrational density of states in vitreous SiO2:: A Raman study

Raman scattering measurements of vitreous SiO2 were performed over a wide range of temperatures in order to study the behavior of the boson peak and the quasielastic scattering. The analysis of quasielastic contribution in the framework of the Jackle model demonstrates that the quasielastic excess and the acoustic attenuation have the same physical origin. Moreover and even more importantly we found that the boson peak decrease, which is observed at increasing temperature, is fully explained by the modification of the elastic constants.