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Vibrational origin of the fast relaxation processes in molecular glass-formers

S. Mossa·G. Monaco·G. Ruocco
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Abstract

We study the interaction of the relaxation processes with the density fluctuations by molecular dynamics simulation of a flexible molecule model for o-terphenyl (oTP) in the liquid and supercooled phases. We find evidence, besides the structural relaxation, of a secondary vibrational relaxation whose characteristic time, few ps, is slightly temperature dependent. This i) confirms the result by Monaco et al. [Phys. Rev, E 62, 7595 (2000)] of the vibrational nature of the fast relaxation observed in Brillouin Light Scattering (BLS) experiments in oTP; and ii) poses a caveat on the interpretation of the BLS spectra of molecular systems in terms of a purely center of mass dynamics.

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S. Mossa, G. Monaco, G. Ruocco. 2001-04-14. Vibrational origin of the fast relaxation processes in molecular glass-formers. https://doi.org/10.1209/epl%2Fi2002-00324-1

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