Molecular dynamics simulation on the tensile behavior of gold nanowires with diameters between 3 and 6 nm

Abstract

Based on the embedded atom method potential, this article presents a molecular dynamics study of gold nanowires with three diameter sizes at a strain rate of 1.4 × 10⁹ s⁻¹ applied in <100> axial orientation. The mechanical properties including Young’s modulus, yielding stresses and yielding strains are computed and compared with available results. The atomic configuration stress–strain curves are given and analyzed in detail. The simulation results show that for the same-length gold nanowires, Young’s modulus and the yielding stress will decrease with the decrease in the diameter size of gold nanowires. Due to surface premelting at room temperature, Young’s modulus of the nanowires with the smallest diameter was about 28.6% smaller than the experimental value of 46.49 GPa. The nanowires displayed crystalline-ordered deformation governed by the formation of a main dislocation plane and the development of subplanes around the main plane. In case of diameters smaller than 5.84 nm, the nanowires experienced a double elastic periods and double plastic periods phenomenon subject to the strain rate and the characteristic size.