拉伸过程中晶向对银单原子线形成几率影响的分子动力学模拟

Molecular Dynamics Simulation of the Influence of Crystal Orientation on the Formation Probability of Silver Monoatomic Chains during Stretching

采用基于原子镶嵌势函数的分子动力学方法,模拟了银纳米线沿[100]、[110]和[111]晶向拉伸过程中的空间原子结构和性能.研究结果表明不同晶向的材料力学性质有显著不同,屈服应力按照[111]、[110]和[100]依次降低.从形变位图观察到纳米线在断裂前形成单原子线排列.由900个分子动力学模拟样本统计得出沿三个晶向形成单原子线的几率,其中沿[111]晶向形成单原子线的几率明显高于其他两个晶向.本文从形变机理阐述了单原子线生成几率与晶向的依赖关系.

We carried out molecular dynamics simulations using an embedded atom method to investigate the mechanical properties and structure deformation of silver nanowires during anisotropic stretching along the [100], [110], and [111] orientations. The simulation results show that the mechanical properties are different for the three crystal directions. Before breaking, linear atomic chains were observed for all three orientations. A total of 900 samples were investigated for a comprehensive understanding of the influence of orientation on the formation probability of linear atomic chains. Stretching along the [111] direction had a higher probability than that along the other two directions. This difference is explained by a stretching mechanism of the silver nanowire.