Laboratoire Charles Coulomb UMR 5221 CNRS/UM2 (L2C)


Accueil > La Recherche > Axes & Equipes > Matière Molle & Verres > Equipe : Physique des Verres > Thème : Structure, vibration, relaxations dans les systèmes désordonnés

Glass-specific behavior in the damping of acousticlike vibrations

par sinfo - publié le , mis à jour le

Involved researchers : B. Rufflé, G. Guimbretière (PhD), E. Courtens, and R. Vacher

(Collaboration G. Monaco, ESRF, Grenoble)

High frequency sound is observed in lithium diborate glass, Li2O-2B2O3, using Brillouin scattering of light and x-rays. The sound attenuation exhibits a non-trivial dependence on the wavevector, with a remarkably rapid increase towards a Ioffe-Regel crossover as the frequency approaches the boson peak from below. An analysis of literature results reveals that the boson-peak frequency is closely related with a Ioffe-Regel limit for sound in many glasses. We conjecture that this relation, specific to glassy materials, might be rather common among them.

Relation between ΩIR and ΩBP from literature data. The points are : (1) LB2 at 573 K ; (2) lithium tetraborate Li2O-4B2O3 at 600 K ; (3) densified silica at 565 K ; (4) vitreous silica at 1050 K ; (5) glycerol at 175 K ; (6) ethanol at 86 K ; (7) selenium at 295 K ; (8) polybutadiene at 140 K ; (9) propylene carbonate at 167 K (Tg + 7 K) ; (10) orthoterphenyl at 156 K. The line is a guide to the eye - © L2C