Ideal strength of a Cu multi-shell nano-wire
Ideal strength of a Cu multi-shell nano-wire
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DOI：
10.1088/0965-0393/14/6/010
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发表时间：
2006-09
影响因子：
1.8
通讯作者：
A. Kushima;Y. Umeno;T. Kitamura
中科院分区：
文献类型：
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作者：
A. Kushima;Y. Umeno;T. Kitamura
纳米组件的理想强度，也就是结构的最大应力，提供了对微小材料的洞察。我们对面心立方晶体中具有(111)层结构的由原子链为核心，壳层包裹的圆柱形铜纳米线(S)进行拉伸模拟。杨氏模数和理想的导线强度小于单个原子链和单原子片。线材的机械强度因以下三个因素而减弱：(A)核壳结合引起的电子排列的变化；(B)为与芯链结合而引入的较大的外壳原子间距离(固有拉伸应变)；以及(C)由于曲率差异导致原子层不匹配而导致外壳上的弱成键(间隙)。因素(A)削弱了占据大部分导线的外壳(S)的结合。由于(A)和(B)的原因，由核和壳组成的5-1线相对于单原子链和单片是弱化的。由一个铁芯和两个外壳组成的10-5-1导线的强度低于5-1导线，因为除了(A)和(B)之外，还有(C)。
The ideal strength of a nano-component, which is the maximum stress of the structure, provides an insight into minute material. We conducted tensile simulations for a cylindrical-shaped Cu nano-wire composed of an atomic chain as a core wrapped around by shell(s) with the structure of (111) layers in a fcc crystal. Young's moduli and the ideal strengths of the wires are less than a single atomic chain and sheet. The mechanical strength of the wire is weakened by the following three factors: (a) changes in electron arrangement caused by combining core and shell; (b) a larger interatomic distance (inherent tensile strain) of the outer shell introduced for combining with the core chain; and (c) weak bonding (gap) on the outer shell caused by the mismatch of atomic layers due to the curvature difference. Factor (a) weakens the bonding of the shell(s) that occupy a greater part of the wire. A 5-1 wire, which consists of a core and a shell, is weakened compared with the single atomic chain and the single sheet due to (a) and (b). A 10-5-1 wire, consisting of a core and two shells, has less strength than a 5-1 wire due to (c) in addition to (a) and (b).