Low temperature phonon damping in vitreous silica explored by UV Brillouin spectroscopy

Giacomo Baldi (1) , Silvia Caponi (2) , Aldo Fontana (2) , Paola Benassi (3) , Andrea Giugni (3) , Michele Nardone (3) , Marco Sampoli (4)

1 Physics
2 Physics
3 Dipartimento di Fisica [L'Aquila]
4 Energetics

The recently developed technique of Brillouin ultraviolet scattering is used to measure phonon dispersion and damping in the prototypical strong glass v-SiO2. Results on the low temperature, T ~ 10 – 100 K, sound attenuation at a frequency around 66 GHz are presented. The comparison between a model which takes into account dynamical processes (thermally activated relaxations and the interaction with the bath of thermal vibrations) and the experimental data indicates the presence of a strong static contribution in the region explored by ultraviolet radiation supporting the presence of a transition between static and dynamic attenuation mechanisms at a frequency around 100 GHz.

Mots clés: Physical Sciences

Giacomo Baldi, Silvia Caponi, Aldo Fontana, Paola Benassi, Andrea Giugni, et al.. Low temperature phonon damping in vitreous silica explored by UV Brillouin spectroscopy. Philosophical Magazine, 2007, 87 (3-5), pp.603-612. ⟨10.1080/14786430600891360⟩. ⟨hal-00513737⟩