Atomistic simulation of plasticity in silicon nanowires

Abstract

We study the tensile deformation of polycrystalline Si nanowires by means of molecular dynamics simulations. The initial microstructure is composed by a network of nanocrystals glued together by a thin layer of amorphous material. Atomistic simulations could clearly identify liquidlike flow in the constrained amorphous Si as the responsible for the observed elongation. After this first stage of nearly constant-stress flow, a necking instability sets in, eventually leading to fracture, at the point when the nanowire diameter becomes comparable to the size of the nanocrystals. © 2010 American Institute of Physics.