Evaluation of terahertz density of vibrational states from specific-heat data: application to silica glass.
The efficiency of the Tikhonov regulation method for the specific-heat phonon spectrum inversion problem is demonstrated. The regulation method is applied to the evaluation of the density of vibrational states from the low-temperature specific heat of a silica glass. The density of states obtained is found to be in good agreement with the results of inelastic neutron scattering. The extracted density of states is used for the analysis of the Raman light-vibration coupling coefficient. It is established that the coupling coefficient increases with frequency faster than approximately nu at nu<10 cm(-1). In the frequency range above 10 cm(-1) the coupling coefficient is found to be in agreement with the results of previous investigations.
Surovtsev
N V
NV
Institute of Automation and Electrometry, Russian Academy of Sciences, pr. Ak. Koptyuga 1, Novosibirsk, 630090, Russia.