Plasticity-induced structural anisotropy of silica glass

Cindy Linn Rountree (1) , Damien Vandembroucq (2) , Mehdi Talamali (2) , Elisabeth Bouchaud (3) , Stéphane Roux (4)

1 SPCSI - Service de Physique et de Chimie des Surfaces et Interfaces
2 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
3 SPEC - UMR3680 - Service de physique de l'état condensé
4 LMT - Laboratoire de Mécanique et Technologie

Amorphous silica density at ambient pressure is known to depend on thermal history (through the quenching rate) but also, at room temperature, on the maximum pressure applied in the past. Here we show that beyond density, a mechanical loading can endow the structure with an orientational order. Molecular dynamics simulations show evidence that amorphous silica develops a permanent anisotropic structure after extended shear plastic flow. This anisotropy which survives for an unstressed specimen is revealed markedly by the fabric tensor computed over the Si-O-Si orientations, albeit the SiO4 tetrahedra microstructure remains mostly unaltered.

Mots clés: silica; glass; amorphous; plasticity; fabric tensor; anisotropy; orientational order

Domaines: Autre [cond-mat.other]

Cindy Linn Rountree, Damien Vandembroucq, Mehdi Talamali, Elisabeth Bouchaud, Stéphane Roux. Plasticity-induced structural anisotropy of silica glass. Physical Review Letters, 2009, 102, pp.195501. ⟨hal-00384141⟩