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通过分子动力学方法模拟了在碳纳米管内填充一定数目的半导体元素硅形成碳纳米管-硅纳米线复合结构的过程,并采用Lindemann指数研究了这种复合结构的热稳定性.计算结果表明,当考虑碳纳米管和硅纳米线轴向方向的周期性边界条件之后,在C(13,0)和C(14,0)碳纳米管内能够形成亚稳结构的硅纳米线Si16NW和Si20NW,从而获得一种碳纳米管-硅纳米线的新型复合结构.通过计算这种复合结构的Lindemann指数,可以看到由于碳纳米管的保护作用,碳纳米管包裹的硅纳米线的熔点远高于自由空间中相同尺寸的硅纳米线熔点.而通过硅纳米线团簇和不同管径的碳纳米管相互作用能的计算,我们发现C(14,0)纳米管除了对Si20NW有一种限制性保护作用之外,对硅纳米线还存在一种径向应力(径向压缩),这种应力使碳纳米管内的Si20NW具有更高的熔点,而当Si20NW轴向方向为自由边界条件时,这种径向应力将通过硅纳米线的形变而释放出来,从而使碳纳米管内的硅纳米线团簇的熔点降低更多.
The process of filling a certain amount of semiconductor element silicon into a carbon nanotube-silicon nanowire composite structure by molecular dynamics simulation was simulated, and the thermal stability of the composite structure was studied by Lindemann index. The calculation results show that, The metastable silicon nanowires Si16NW and Si20NW can be formed in C (13,0) and C (14,0) carbon nanotubes after considering the periodic boundary conditions of the carbon nanotubes and the axial direction of the silicon nanowires. A novel composite structure of carbon nanotubes-silicon nanowires was obtained.By calculating the Lindemann index of this composite structure, it can be seen that due to the protection of carbon nanotubes, the melting point of silicon nanowires wrapped by carbon nanotubes is much higher than that of free Space of the same size of the melting point of silicon nanowires.With the calculation of the interaction energy between silicon nanowire clusters and different diameter carbon nanotubes, we found that C (14,0) nanotubes have a limited protective effect on Si20NW In addition, there is a radial stress (radial compression) on the silicon nanowires, which causes the Si20NW in the carbon nanotubes to have a higher melting point. When the axial direction of the Si20NW is a free boundary condition, this diameter Will release the stress by the deformation of the silicon nanowire, such that the melting point of silicon nanowire clusters in a greater reduction in carbon nanotubes.