Fitting the low-frequency Raman spectra to boson peak models: glycerol, triacetin and polystyrene

A computational approach was elaborated to explicitly account for the Rayle igh line wing, the Boson peak and vibrational contributions to the low-freq uency Raman spectra of amorphous solids and viscous liquids. It was shown t hat the low-frequency Raman spectra of glycerol and polystyrene consist of the Rayleigh contribution of Lorentzian form and the Boson peak which profi le follows the predictions of the theory by Martin and Brenig in the versio n by Malinovsky and Sokolov. In the case of triacetin, the Boson peaks deca y faster in their high-frequency side than the above theory predicts. Their form can be successfully modeled with a newly introduced empirical functio n intermediate between the Martin-Brenig and Malinovsky-Sokolov predictions . (C) 1999 Elsevier Science B.V. All rights reserved.