多壁碳纳米管外壁高温蒸发的分子动力学模拟

采用经典分子动力学（MD）方法，使用EDIP（environment-dependent interatomic potential)势描述C纳米管内C原子之间相互作用，对多壁C纳米管由于Stone-Wales缺陷引起外层管高温剥落蒸发现象进行了计算模拟.研究结果表明，高温下多壁C纳米管外层管Stone-Wales缺陷处C原子剧烈振动导致C—C键断裂形成悬键，并逐渐向四周扩散导致外层管剥落蒸发.利用Lindemann指数作为判据，得出多壁C纳米管外层管出现剥落蒸发的温度为2290 K左右，与Huang Jianyu等实验中观测到多壁C纳米管外层管剥落蒸发现象产生的温度2000 ℃基本一致. 关键词： 多壁C纳米管 分子动力学 Stone-Wales缺陷 剥落蒸发

Molecular dynamics simulation of the evaporation of the surface wall of multi-wall carbon nanotubes at high temperature

We have used molecular dynamics(MD)simulation to investigate the evaporation of the surface wall of multi-wall carbon nanotubes(MWCNTs)at high temperature,using the environment dependent interatomic potential(EDIP)to describe the C-C interaction in carbon nanotube.The simulation results show that the Stone-Wales defect in the surface wall of a multi-wall carbon nanotube vibrates violently.which causes C-C bond breaking and evaporation of atoms along the circumferential directions of the nanotube.The formation of Stone-Wales defect is attributed to the atomic thermal motion or tensile strain.Using the Lindemann index as a criterion,we found that the surface wall of MWCNT evaporates around 2290 K.Our simulation results agree very well with the observation of the surface wall evaporation of the MWCNT at 2000℃.