Thermal conductivity of single-walled carbon nanotubes

We have measured the temperature-dependent thermal conductivity kappa(T) of crystalline ropes of single-walled carbon nanotubes from 350 K to 8 K. kap pa(T) decreases smoothly with decreasing temperature, and displays linear t emperature dependence below 30 K. Comparison with electrical conductivity e xperiments indicates that the room-temperature thermal conductivity of a si ngle nanotube may be comparable to that of diamond or in-plane graphite, wh ile the ratio of thermal to electrical conductance for a given sample indic ates that the thermal conductivity is dominated by phonons at all temperatu res. Below 30 K, the linear temperature dependence and estimated magnitude of kappa(T) imply an energy-independent phonon mean free path of similar to 0.5-1.5 mu m. [S0163-1829(99)50404-9].