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(122) Production(s) de VACHER R.
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Boson peak and its relation to acoustic attenuation in glasses 
Auteur(s): Ruffle B., Parshin D. a., Courtens E., Vacher R.
(Article) Publié:
Physical Review Letters, vol. 100 p.015501 (2008)
Ref HAL: hal-00512617_v1
Exporter : BibTex | endNote
Résumé: Experimental results on the density of states and on the acoustic modes of glasses in the THz region are compared to the predictions of two categories of models. A recent one, solely based on an elastic instability, does not account for most observations. Good agreement without adjustable parameters is obtained with models including the existence of nonacoustic vibrational modes at THz frequency, providing in many cases a comprehensive picture for a range of glass anomalies.
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The Boson peak and its Relation with Acoustic Attenuation in Glasses
Auteur(s): Ruffle B. , D Parshin, Courtens E., Vacher R.
Conference: XI International Workshop on Complex Systems (Andalo, IT, 2008-03-16)
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High Frequency Sound in Glasses
Auteur(s): Ruffle B., D Parshin, Courtens E., Vacher R.
Conference: 22 nd General conference of the condensed matter division of the european physical society (Rome, Italy, FR, 2008-08-25)
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Hyper-Raman scattering analysis of the vibrations in vitreous boron oxide
Auteur(s): Simon Guilhem, Hehlen B., Vacher R., Courtens E.
(Article) Publié:
Physical Review B, vol. 76 p. (2007)
Résumé: Hyper-Raman scattering has been measured on vitreous boron oxide, v-B2O3. This spectroscopy, complemented with Raman scattering and infrared absorption, reveals the full set of vibrations that can be observed with light. A mode analysis is performed based on the local D-3h symmetry of BO3 triangles and B3O3 boroxol rings. The results show that in v-B2O3 the main spectral components can be successfully assigned using this relatively simple model. In particular, it can be shown that the hyper-Raman boson peak arises from external modes that correspond mainly to librational motions of rigid boroxol rings.
Commentaires: 1098-0121 054210
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Reply to comment on "Glass-specific behavior in the damping of acoustic-like vibrations"
Auteur(s): Ruffle B., Guimbretiere Guillaume, Courtens E., Vacher R., Monaco G.
(Article) Publié:
Physical Review Letters, vol. 98 p.079602 (2007)
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Elasticity and anelasticity of oxide glasses
Auteur(s): Courtens E., Foret M., Ruffle B., Vacher R.
(Article) Publié:
European Journal Of Glass Science And Technology: Part B - Physics And Chemistry Of Glasses, vol. 48 p.9-18 (2007)
Ref HAL: hal-00512649_v1
Exporter : BibTex | endNote
Résumé: The current understanding of sound properties in glasses is reviewed and compared to that in crystals. Sound damping in oxide glasses is controlled mainly by three processes which in increasing order of the frequency at which they dominate are: the thermal relaxation of defects, relaxation via anharmonic interactions with the thermal bath, and hybridization with optic-like vibrations. The former two also affect distinctly the velocity of sound. The latter one relates to the boson peak and the low temperature plateau generally observed in the thermal conductivity. In addition, in silica and other tetrahedrally coordinated glasses, the sound velocity tends to increase with temperature, presumably owing to a progressive structural change.
Commentaires: 0031-9090
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