Inhomogeneous elastic response of silica glass.
Using large scale molecular dynamics simulations we investigate the properties of the nonaffine displacement field induced by macroscopic uniaxial deformation of amorphous silica, a strong glass according to Angell's classification. We demonstrate the existence of a length scale xi characterizing the correlations of this field (corresponding to a volume of about 1000 atoms), and compare its structure to the one observed in a standard fragile model glass. The "boson-peak" anomaly of the density of states can be traced back in both cases to elastic inhomogeneities on wavelengths smaller than xi where classical continuum elasticity becomes simply unapplicable.
Léonforte
F
F
Laboratoire de Physique de la Matière Condensée et des Nanostructures Université Lyon I, CNRS, UMR 5586, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
Tanguy
A
A
Wittmer
J P
JP
Barrat
J-L
JL