Thermal Conductance of Individual Single-Wall Carbon Nanotubes

This work presents an experimental study of phonon transport in individual suspended single-wall carbon nanotubes (SWCNTs). Through the use of a micro fabricated device consisting of two adjacent suspended membranes, each with a platinum resistance heater and thermometer, the thermal conductance of several individual SWCNTs has been directly measured over the temperature range of 100 to 490 K. The effects of Umklapp phonon-phonon scattering remain weak and the thermal conductance remains roughly proportional to the calculated ballistic conductance throughout the temperature range. The macroscopic thermal conductance increases with temperature throughout the temperature range indicating static scattering processes or contact thermal resistance dominate transport in this regime. These results are an order of magnitude lower than the predicted ballistic thermal conductance calculated for a defect-free (18,0) nanotube. The results contrast with thermal conductance measurements reported using a high-bias DC self heating method. The discrepancy is discussed in terms of the differences in the contact thermal resistance, defects, and measurement methods.