Stone-Wales transformations triggered by intrinsic localized modes in carbon nanotubes
Stone-Wales transformations triggered by intrinsic localized modes in carbon nanotubes
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DOI：
10.1103/physrevb.81.035401
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发表时间：
2010-01
影响因子：
3.7
通讯作者：
T. Shimada;Daisuke Shirasaki;T. Kitamura
中科院分区：
文献类型：
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作者：
T. Shimada;Daisuke Shirasaki;T. Kitamura
利用分子动力学模拟方法研究了（5，5）扶手椅型碳纳米管（CNT）在轴向拉伸作用下，原子尺度内禀局域模（ILMs）作为缺陷成核触发器的关键作用.一对相邻原子的局部振动被发现是ILM，它同时产生强烈的动能集中，即使在结构均匀的CNT。C-C相互作用的非线性使激发态的ILM逐渐放大。放大的ILM，然后，驱动的现场C-C键的断裂，这导致斯通-威尔士变换产生的拓扑缺陷组成的两个五边形和两个七边形耦合成对。这意味着机械不稳定性可以由ILM激活。这种机制预计将适用于其他机械不稳定性，例如，作为硅在静水压力下相变的起源。
The crucial role of intrinsic localized modes (ILMs) in the atomic scale as a trigger of defect nucleation was studied using molecular-dynamics simulations for a (5,5) armchair carbon nanotube (CNT) under axial tension. A localized vibration at a pair of neighboring atoms was found to be the ILM, which simultaneously produces an intense concentration of kinetic energy, even in the structurally homogeneous CNT. The excited ILM was gradually amplified by the nonlinearity of C-C interaction. The amplified ILM, then, drove the breaking of the on-site C-C bond, which leads to the Stone-Wales transformation producing a topological defect consisting of two pentagons and two heptagons coupled in pairs. This signifies that mechanical instability can be activated by the ILMs. Such mechanism is expected to apply to other mechanical instabilities, e.g., as an origin of phase transformations in silicon under hydrostatic pressure.