基于线性波尔兹曼输运方程和碳纳米管的色散关系,本文研究了声子散射的Umklapp和Normal过程同时存在时单壁碳纳米管的晶格热导率,以及温度、管长和管径对它的影响。结果表明:N过程的影响在高温不能忽略;对(10,0)管而言,在低温下其导热率随温度升高迅速增大,在90 K附近达到最大值,然后逐渐开始下降;热导率与管长L的关系是κχL~(1/2);在相同管长和温度下,热导率随管径的减小而增大。
The lattice thermal conductivity of single-walled carbon nanotubes (SWCNTs) was calculated using the elementary kinetic theory and the phonon dispersion relations of SWCNTs. In the calculation, both Umklapp and Normal process of phonon scattering were considered. The results shows that: the effect of N-process should not be neglected in high temperature; as for (10,0) tube, the thermal conductivity increases rapidly in low temperature and reaches the peak around 90 K, then decreases slowly; the thermal conductivity diverges with the tube length, L, as κ α L1/2; with the same temperature and tube length, thermal conductivity decreases with the increase of the diameter of tube.