单壁碳纳米管声子谱及比热计算

Phonon spectra and specific heat calculation of single wall carbon nanotube

利用卷曲法计算了有限长单壁碳纳米管的声子色散关系.讨论了单壁碳纳米管的比热随管径、温度的变化趋势.结果表明碳管的比热随温度、管径的增大而增大,并逐渐趋于一恒定数值.根据色散关系的计算结果,给出了有限长(5,5)型单壁碳纳米管的振动模式以及部分振动模式的频率随长度的变化关系.

In this paper, the phonon spectra of infinite length single-wall carbon nanotubes are calculated based on the force constant model. The dependence of specific heat on the tube diameter and temperature is discussed. It is found that the specific heat will increase with increasing temperature and diameter and approaches to a constant value. Also, the vibrational spectra of the finite length （5,5） carbon nanotube are calculated. The relationships between the vibrational frequency and length are presented for some particularly modes.