Shock-induced breaking in the gold nanowire with the influence of defects and strain rates

Abstract

Defects in metallic nanowires have raised concerns about the applied reliability of the nanowires in nanoelectromechanical systems. In this paper, molecular dynamics simulations are used to study the deformation and breaking failure of the [100] single-crystal gold nanowires containing defects at different strain rates. The statistical breaking position distributions of the nanowires show mechanical shocks play a critical role in the deformation of nanowires at different strain rates, and deformation mechanism of the nanowire containing defects is based on a competition between shocks and defects in the deformation process of the nanowire. At low strain rate of 1.0% ps(-1), defect ratio of 2% has changed the deformation mechanism because micro-atomic fluctuation is in an equilibrium state. However, owing to strong symmetric shocks, the sensitivity of defects is not obvious before a defect ratio of 25% at high strain rate of 5.0% ps(-1).

Shock-induced breaking of the nanowire with the dependence of crystallographic orientation and strain rate

“…The first and second terms in the right side of the above equation represent the thermal effect and the atomic interactions, respectively. All the presented MD simulations and visualization process were performed with the self-developed software NanoMD [36], the reliability of algorithms has been validated not only by a large amount of theoretical simulations [25,26,37-41], but also with the comparison to the experimental measurements [42,43]. …”

Uniaxial tension-induced fracture in gold nanowires with the dependence on size and atomic vacancies

“…Through microstructure design, a near-ideal strength has been discovered in gold nanowires with special defects. 13 The influence of defects on the formation of one-atom constriction in gold nanowires has been presented by Silva et al 14 We also discovered that the tensile deformation mechanism was related to competition between the tensile action and the constructed atomic vacancies at different strain rates 15 and temperatures. 16,17 For the investigation of the influence of atomic vacancies at such a small scale, we focused on the microscopic deformation mechanisms and macroscopic fracture behaviors of singlecrystal gold nanowires containing atomic vacancies.…”

“…Regarding the effect of strain rate, 1.0% ps À1 , a high strain rate for any materials and structures from a macroscopic viewpoint, was chosen because the strain rate could be considered as a quasi-static state of the gold nanowire, which could allow avoidance of the strain rate effect towards different nanowire sizes as much as possible. [15][16][17] In this study, two sizes of gold nanowires were selected, (3a  3a  9a) and (9a  9a  27a) (''a'' stands for lattice constant, 0.408 nm for gold). The size selection was carried out according to the previous work considering the influence of nanowire lengths on their fractures.…”

Molecular dynamics simulations of void effect of the copper nanocubes under triaxial tensions

“…Due to the obvious necking of nanocubes, the true stress σ and the logarithmic strain ε are proposed by [30] σ = σ (1 + ε), (9) …”

“…Three-dimensional FEM are completely different from molecular dynamics method. The different model styles including nanowires [9][10][11] and nanoimprint [12], different void styles including crack [13], point defect [14] and line defect [15], and the different analysis styles including plasticity deformation mechanism [16], collision cascades [17] and ductile failures [18], were all considered.…”