Micro-plasticity in a fragile model binary glass

Atomistic deformation simulations in the nominally elastic regime are performed for a model binary glass with strain rates as low 104/s (corresponding to 0.01 shear per 1 µs). A rate dependent softening due micro-plasticity is observed, which mediated by thermally-activated localized structural transformations (LSEs). closer inspection of atomic-scale structure indicates material response distinctly different two types local atomic environments. system spanning iscosahedrally coordinated substructure responds purely elastically, whereas remaining admits both and microplastic evolution. This leads heterogeneous internal stress distribution which, upon unloading, results negative creep complete residual-strain recovery. detailed analysis terms stress, displacement, SU(2) bonding topology shows such microscopic processes can result large changes more likely occur geometrically frustrated regions characterized higher free volume softer stiffness. The LSE activity also mediates relaxation, this way should be distinguished from stress-driven transformation only rejuvenates structure. frequency activity, therefore amount micro-plasticity, found related degree glassy state relaxed. These insights shed atomistic light onto origins that may govern recent experimental observations significant evolution loading protocols.