Precise low-frequency internal friction measurements on vitreous silica, taken over a wide temperature (4K < T < 300 K) and frequency range (40 Hz < nu < 14 kHz), show remarkable similarities, but also suggestive differences with recent light scattering experiments. In the interval 30K < T < 110 K, the exponent alpha of the power law relaxational spectrum turns out to be proportional to T-T(k), with a minimum at around T(k) = 13K. This phenomenon is interpreted as a manifestation of thermal activation in an asymmetric double well system, the asymmetry being associated to quenched spatial disorder. For T > 160K the loss angle develops a distinct step-like structure followed by a plateau, both independent of nu, thus signalling the onset of a competing relaxation mechanism with much higher an activation energy. Copyright (C) EPLA, 2007.

Low-frequency internal friction in silica glass

F. Travasso;MARCHESONI, Fabio
2007-01-01

Abstract

Precise low-frequency internal friction measurements on vitreous silica, taken over a wide temperature (4K < T < 300 K) and frequency range (40 Hz < nu < 14 kHz), show remarkable similarities, but also suggestive differences with recent light scattering experiments. In the interval 30K < T < 110 K, the exponent alpha of the power law relaxational spectrum turns out to be proportional to T-T(k), with a minimum at around T(k) = 13K. This phenomenon is interpreted as a manifestation of thermal activation in an asymmetric double well system, the asymmetry being associated to quenched spatial disorder. For T > 160K the loss angle develops a distinct step-like structure followed by a plateau, both independent of nu, thus signalling the onset of a competing relaxation mechanism with much higher an activation energy. Copyright (C) EPLA, 2007.
2007
262
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11581/224102
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact