Highlighting the impact of shear strain on the SiO2 glass structure: From experiments to atomistic simulations

Martinet, C.; Heili, M.; Martinez, V.; Kermouche, G.; Molnar, G.; Shcheblanov, N.; Barthel, E.; Tanguy, A.

Journal of Non-Crystalline Solids 533 (2020)

SiO2 glass structure has been permanently modified by uniaxial compression. Within such a loading, the structure is supposed to be affected both by densification and shear flow. We propose to compare recovered silica samples with similar densities, initially deformed plastically under a hydrostatic compression or under a uniaxial compression. From micro-Raman spectroscopy experiments, the shear strain effects have been highlighted on the structural modifications of the glass and have been confirmed from molecular dynamic simulations. In particular, medium range order depends on the mechanical history in plastically deformed glasses. Indeed, both experiments and simulations demonstrate that small rings are favored when permanent shear strain acts with densification, thus allowing a structural signature identification of the densification process.