Divergent and Ultrahigh Thermal Conductivity in Ultralong Nanotubes
Victor Lee1,2, Zong-Xing Lou1,2, Chi-Hsun Wu1,2*, Wei-Li Lee3, Chih-Wei Chang1
1Center for Condensed Matter Science, National Taiwan University, Taipei, Taiwan
2Department of Physics, National Taiwan University, Taipei, Taiwan
3Institute of Physics, Academia Sinica, Taipei, Taiwan
* presenting author:吳奇勳, email:woslessh02@yahoo.com.tw
Many studies have reported non-Fourier heat conduction phenomena occur in one dimensional system; in other word, the empirical Fourier’s law breakdown, which is critical for the research of thermal transportation. For Fourier heat conduction, the thermal conductivity (κ) would be a constant with respect to the temperature and the property of material. However, in one dimensional system, κ would diverge as the length (L) of the system increasing, i.e. κ ~ Lβ.Since few experimental results focus on this topic, we conducted the thermal conductivity measurements of ultralong single-wall carbon nanotubes (SWCNTs) as a quasi-one dimension system. It had been observed that κ increased with lengths and reach an unprecedented high value at room temperature for ultralong SWCNTs.The discovery of ultrahigh κ and its divergent behavior could open an unbounded domain for phononic applications, including channeling heat waves, directing thermal energy along with processing phononic information.

Keywords: phonon, thermal transport, thermal conductivity, carbon nanotubes, Fourier's law