Effects of surface atomistic modification on mechanical properties of gold nanowires

• Molecular dynamics simulations of surface modification effect of Au nanowires.
• Surface modification can greatly affect the mechanical properties of nanowires.
• Core–shell model is used to elucidate the effect of residual surface stress.

Modulation of the physical and mechanical properties of nanowires is a challenging issue for their technological applications. In this paper, we investigate the effects of surface modification on the mechanical properties of gold nanowires by performing molecular dynamics simulations. It is found that by modifying a small density of silver atoms to the surface of a gold nanowire, the residual surface stress state can be altered, rendering a great improvement of its plastic yield strength. This finding is in good agreement with experimental measurements. The underlying physical mechanisms are analyzed by a core–shell nanowire model. The results are helpful for the design and optimization of advanced nanomaterial with superior mechanical properties.