Raman microspectroscopic characterization of amorphous silica plastic behavior

Raman microspectroscopy was used to characterize amorphous silica plastic behavior. Using a correlation between Raman spectrum and density, a map of the local residual indentation-induced densification was obtained. The existence of a densification-induced hardening was also evidenced through a diamond-anvil cell experiment. Such observations are not accounted for by the previously proposed hardening-free pressure-dependent yield criterion based on indentation curves. These results open the way toward a more accurate description of a constitutive law for amorphous silica.