Nondynamic Origin of the High-Frequency Acoustic Attenuation in Glasses

G. Ruocco (1, 2) , F. Sette (3) , R. Di Leonardo (4) , D. Fioretto (5, 6) , Michael Krisch (3) , Maren Lorenzen (3) , Claudio Masciovecchio (3) , G. Monaco (3) , Frédéric Pignon (7) , T. Scopigno (8)

1 Istituto Nazionale di Fisica della Materia
2 CNR-INFM CRS-SOFT, Universitá di Roma “La Sapienza,”
3 ESRF - European Synchrotron Radiation Facility
4 Dipartimento di Fisica [L'Aquila]
5 Research Center SOFT INFM-CNR, c/o Universita di Roma ”La Sapienza”
6 Dipartimento di Fisica, Universita di Perugia
7 LR - Laboratoire de rhéologie
8 Dipartimento di Fisica and INFM

The sound attenuation in the THz region is studied down to T _ 16 K in glassy glycerol by inelastic x-ray scattering. At striking variance with the decrease found below _100 K in the GHz data, the attenuation in the THz range does not show any T dependence. This result (i) indicates the presence of two different attenuation mechanisms, active, respectively, in the high- and low-frequency limits, (ii) demonstrates the nondynamic origin of the attenuation of THz sound waves, and confirms a similar conclusion obtained in SiO2 glass by molecular dynamics, and (iii) supports the low-frequency attenuation mechanism proposed by Fabian and Allen.

Mots clés: XPCS; Glasses; Silica; sound attenuation

Domaines: Mécanique des fluides [physics.class-ph]; Matière Molle [cond-mat.soft]; Génie des procédés

G. Ruocco, F. Sette, R. Di Leonardo, D. Fioretto, Michael Krisch, et al.. Nondynamic Origin of the High-Frequency Acoustic Attenuation in Glasses. Physical Review Letters, 1999, 83 (26), pp.5583-5586. ⟨hal-00341485⟩