Ultra-large Scale Molecular Dynamics Simulation for Nano-engineering

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

The size effect dominates the rupture of gold nanowires, which is also related to atomic vacancies in a single-layer crystalline plane.

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

The failure of the metallic nanowire has raised concerns due to its applied reliability in nanoelectromechanical system. In this article, the breaking failure is studied for the [100], [110], and [111] single-crystal copper nanowires at different strain rates. The statistical breaking position distributions of the nanowires have been investigated to give the effects of strain rate and crystallographic orientation on micro-atomic fluctuation in the symmetric stretching of the nanowires. When the strain rate is less than 0.26% ps-1, macro-breaking position distributions exhibit the anisotropy of micro-atomic fluctuation. However, when the strain rate is larger than 3.54% ps-1, the anisotropy is not obvious because of strong symmetric shocks.

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

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).

Nanoscale interface of metals for withstanding momentary shocks of compression

The failure of the nanoscale metallic interface has raised concerns owing to the effect interfacial amalgamation has on its application in nanoelectronic devices. Single crystal copper [110] and [100], which are set as two components of [110]‖[100] nanocrystalline copper, are used to simulate the interfacial properties using molecular dynamics simulations. Repeated tension and compression cycles show that the two components of the interface can come into contact and separate without interfacial amalgamation. The [110]‖[100] interface could withstand momentary shocks of compression and heat produced by the momentary shocks. This property of the [110]‖[100] interface is dominated by crystalline orientations of interfacial structure, in comparison with [111]‖[100] and [111]‖[110] interfaces under the same conditions.

Theoretical investigation on the influence of temperature and crystallographic orientation on the breaking behavior of copper nanowire

In this paper, molecular dynamics simulations have been conducted to study the mechanical stretching of copper nanowires which will finally lead to the formation of suspended liner atomic chains. A total of 2700 samples have been investigated to achieve a comprehensive understanding of the influence of temperature and orientation on the formation of linear atomic chains. Our results prove that linear atomic chains do exist for [100], [111] and [110] crystallographic directions. Stretching along the [111] direction exhibits a higher probability in forming the two-atom contact than that along the [110] and [100] directions. However, for longer linear atomic chains, there emerges a reversed trend. In addition, increasing temperature may decrease the formation probability for stretching along [111] and [110] directions, but this influence is less obvious for that along the [100] direction.