High-density liquid-like component facilitates plastic flow in a model amorphous silicon system

Abstract

ABSTRACTMolecular dynamics simulations show that plastic deformation behavior of model Stillinger-Weber amorphous Si is very sensitive to the density of the initial unstressed state. Low-density systems exhibit a pronounced yield phenomenon, strain softening, and a dramatic drop in pressure during deformation at constant volume. This behavior is explained by the interplay in every system of the prevailing solid-like and liquid-like components, with the latter being denser and more amenable to plastic flow.