Vitreous silica distends in helium gas: acoustic vs. static compressibilities

Coralie Weigel (1) , Alain Polian (2) , Mathieu Kint (1) , Benoit Ruffle (1) , Marie Foret (1) , René Vacher (1)

1 L2C - Laboratoire Charles Coulomb
2 IMPMC - Institut de minéralogie et de physique des milieux condensés

Sound velocities of vitreous silica are measured under He compression in the pressure range 0-6 GPa by Brillouin light scattering. It is found that the well-known anomalous maximum in the pressure dependence of the compressibility is suppressed by He incorporation into the silica network. This shows that the elastic anomaly relates to the collapse of the largest interstitial voids in the structure. The huge difference between the static and the acoustic compressibilities indicates that the amount of incorporated helium still increases at 6 GPa.

Domains: Materials Science [cond-mat.mtrl-sci]; Other [cond-mat.other]

Coralie Weigel, Alain Polian, Mathieu Kint, Benoit Ruffle, Marie Foret, et al.. Vitreous silica distends in helium gas: acoustic vs. static compressibilities. Physical Review Letters, 2012, 109 (24), pp.245504. ⟨10.1103/PhysRevLett.109.245504⟩. ⟨hal-00749172⟩