Uniaxial tension-inducedfracture in gold nanowires with the dependence on size and atomic vacancies
Uniaxial tension-inducedfracture in gold nanowires with the dependence on size and atomic vacancies
复制标题
金纳米线中单轴张力诱导断裂与尺寸和原子空位的关系
DOI：
10.1039/c4cp03556a
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发表时间：
2014
影响因子：
3.3
通讯作者：
Qianjin Li
中科院分区：
文献类型：
--
作者：
Fenying Wang;Yanfeng Dai;Jianwei Zhao;Qianjin Li
原子空位在单轴拉伸下金属纳米线的变形和断裂过程中起着重要的作用。然而，用实验方法探索这种演化是一个巨大的挑战。本文采用分子动力学模拟方法研究了不同原子空位和尺寸的金纳米线的形变、断裂机制和力学特性。观察到一些有价值的结果。首先，断裂位置的统计分布显示了金纳米线的两种断裂方式。小尺寸的金纳米线表现为无序晶体结构的团簇断裂，断裂位置出现在中间区域;而大尺寸的金纳米线表现为有序滑移断裂，容易在两端断裂。第二，大尺寸金纳米线的断裂位置分布对原子空位的敏感性高于小尺寸金纳米线。第三，减小金纳米线的尺寸可以提高其机械强度。最后，由于表面原子效应，小尺寸的金纳米线具有不确定的特性。
Atomic vacancies play an important role in the deformation and fracture processes of a metallic nanowire subjected to uniaxial tension. However, it is a great challenge to explore such evolution by experimental methods. Here, molecular dynamics simulations were used to study the deformation, fracture mechanism and mechanical character of gold nanowires with different atomic vacancies and sizes. Several valuable results were observed. Firstly, the statistical breaking position distributions showed two fracture styles of the gold nanowires. The small-sized gold nanowire exhibited a cluster rupture with disordered crystalline structures, and the breaking position appeared in the middle region, while the gold nanowire of large size exhibited an ordered slippage rupture and was apt to break at both ends. Secondly, the breaking position distribution of the large-sized gold nanowire was more sensitive to atomic vacancies than that of the small-sized gold nanowire. Thirdly, the mechanical strength could be improved by decreasing the gold nanowire size. Finally, small-sized gold nanowires had uncertain characteristics owing to the surface atom effects.