An atomistic investigation of elastic and plastic properties of Au nanowires

In this study, mechanical properties of cylindrical gold nanowires with diameters ranging from 5 nm to 17.5 nm were investigated using atomistic computer simulations. Displacement-controlled tensile tests were carried out to investigate the role of defects such as surface steps and twin boundaries commonly found in electrodeposited wires. The high surface-to-volume ratio of nanowires plays a critical role in the mechanical properties. Yield stress was found to be significantly affected by any disturbance in surface morphology. Twin boundaries were not more favorable as a source for dislocation nucleation but disturbed the surface in the neighborhood of the twin, resulting in lower yield strength. Twin boundaries are seen as obstacles for the propagation of dislocations leading to some hardening effects.