Intra-molecular origin of the fast relaxations observed in the Brillouin light scattering spectra of molecular glass-formers

G. Monaco; S. Caponi; R. Di Leonardo; D. Fioretto; G. Ruocco

doi:10.1103/physreve.62.r7595

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Intra-molecular origin of the fast relaxations observed in the Brillouin light scattering spectra of molecular glass-formers

G. Monaco·S. Caponi·R. Di Leonardo·D. Fioretto·G. Ruocco

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Abstract

The Brillouin light scattering spectra of the o-terphenyl single crystal are compared with those of the liquid and the glass phases. This shows: i) the direct evidence of a fast relaxation at 5 GHz in both the single crystal and the glass; ii) a similar temperature dependence for the attenuation of the longitudinal sound waves in the single crystal and the glass; and iii) the absence of coupling between the fast relaxation and the transverse acoustic waves. These results allow us to assign such a relaxation to the coupling between the longitudinal acoustic waves and intra-molecular vibrations, and therefore to exclude any relationship between it and the glass transition.

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G. Monaco, S. Caponi, R. Di Leonardo, D. Fioretto, G. Ruocco. 2000-09-01. Intra-molecular origin of the fast relaxations observed in the Brillouin light scattering spectra of molecular glass-formers. https://doi.org/10.1103/physreve.62.r7595

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