The effect of gas environment on electrical heating in suspended carbon nanotubes

We report micro-Raman spectroscopy measurements of the temperature distribution of current-carrying, 5 μm long, suspended carbon nanotubes in different gas environments near atmospheric pressure. At the same heating power, the measured G band phonon temperature of the nanotube is found to be significantly lower in gaseous environments than in vacuum. Theoretical analysis of these results suggests that about 50%-60% of the heat dissipated in the suspended nanotube is removed by its surrounding gas molecules, and that the thermal boundary conductance is higher in carbon dioxide than in nitrogen, argon, and helium, despite the lower thermal conductivity of carbon dioxide. © 2010 American Institute of Physics.