Onset of plasticity in gold nanopillar compression

Abstract

On the basis of a series of molecular dynamics simulations of the compressive deformation of 〈111〉-oriented gold nanopillars, we demonstrate that slip nucleates at surface features for which the amplitude of thermal vibrations is a maximum. This leads to a yield stress which can be either a linear or parabolic function of temperature, depending on the strength with which atoms are bound to the surface. Changing the surface structure by removing weakly bound atoms produces a striking rise in yield strength and a change in its temperature dependence. © 2007 American Chemical Society.