温度对单壁碳纳米管端口结构的影响

利用紧束缚势分子动力学模拟方法，研究了温度在2000—3500 K之间单壁碳纳米管端口结构的变化趋势.研究表明，温度对整个管端口结构起关键作用，计算表明温度在3000K和3500K下碳管两端口在15ps时间尺度内依次闭合，温度高易于使理想单壁碳管端口封闭，且端口封闭导致碳管系统能量的降低.由于Armchair型碳纳米管与相同半径的Zigzag型碳纳米管相比有相对低的应力能，导致Armchair型碳纳米管更易形成端口封闭的结构. 关键词： 碳纳米管 紧束缚势

End structures of single-walled carbon nanotube at different temperatures

We have simulated the end structures of perfect single-walled carbon nanotube at temperatures from 2000 K to 3500 K using tight binding molecular dynamics method. Our calculations suggest that the effect of temperature on the ends of the nanotubes is important. The two ends of a perfect single-walled carbon nanotube closes in turn at 3000 K and 3500 K within 15 ps. As the temperature increases, the two ends of a perfect single-walled carbon nanotube will close more quickly. Both processes of closing of two ends are accompanied by the lowing of the system energy. Moreover, the ends of armchair-type carbon nanotube close easier than those of zigzag carbon nanotube with the same diameter due to the lower strain energy of the former.