The size dependence of the mechanical properties and breaking behavior of metallic nanowires: A statistical description

Molecular dynamics simulations have been performed with an embedded-atom method to study the size dependence of the mechanical properties and the breaking behavior of copper nanowires aligned in the [1 0 0] direction. By statistical analysis with 300 samples for each cross-section, we have found that the average Young’s modulus and yield stress increase with increasing cross-sectional area when its side length exceeds 1.09 nm. However, for the systems smaller than this value, the average Young’s modulus presents an exceptional high value. The final breaking positions for each cross-section follow a Gaussian distribution with a most probable breaking position (MPBP). When the side length is greater than 2.20 nm, the MPBP locates at the center of the nanowire. As the side length is reduced, the MPBP shifts to the two ends, inferring a confinement of boundary on the mechanical shock-wave.