Anomalous heat conduction in a carbon nanowire: Molecular dynamics calculations

Heat conduction of a real quasi-one-dimensional material, the finite length carbon nanowire inserted into the single-walled carbon nanotube (SWNT), has been studied by the molecular dynamical method, in which both of the longitudinal as well as transverse motions of the chain atoms in the SWNT have been permitted. It is found that the thermal conductivity $\kappa$ of the carbon nanowire is very high at room temperature and diverges more likely with the chain length logarithmically.

Figure 1

The temperature profiles on the chain at $T_L=0.03$ and $T_R=0.025$, with $N=64$ (solid line) and 128 (dash-dot lines). The averages are carried over a time interval of ${10}^4\text{–}{10}^5$. The distance between CNW atoms is $1.844\mathrm{\AA }$. (a) Eighth-order Runge-Kutta algorithm. (b) Velocity Verlet algorithm.

Figure 2

Thermal conductivity of the CNW as a function of its length. $a_0=1.844\mathrm{\AA }$. (a) Linear-logrithm plot. (b) Log-log plot. The solid lines in (a) and (b) are used for guiding eyes.

Figure 3

Statistical radial distribution for the motion of wire atoms perpendicular to the tube axis.

Figure 4

The length dependence of thermal conductivity of the perfect 1D carbon chain model.

Figure 5

Heat flux autocorrelation function of CNW with 64 particles.

Figure 6

The final temperature distributions of 512 particles evolved from different initial temperature profiles. (a) Low initial temperature. (b) Linear initial temperature. (c) High initial temperature. (d) Average of (a), (b), and (c).