Measurement of thermal conductivity of individual multiwalled carbon nanotubes by the 3-ω method

Abstract

The thermal conductivity of individual multiwalled carbon nanotubes (outer diameter of $\sim 45\mathrm{nm}$ ) was obtained by employing the $3\text{-}\omega$ method. To this end, the third-harmonic amplitude as a response to the applied alternate current at fundamental frequency $\left(\omega \right)$ is expressed in terms of thermal conductivity. A microfabricated device composed of a pair of metal electrodes $1\mu \mathrm{m}$ apart is used to place a single nanotube across the designated metal electrodes by utilizing the principle of dielectrophoresis. The multiwalled carbon nanotube was modeled as a one-dimensional diffusive energy transporter and its thermal conductivity was measured to be $650–830\mathrm{W}∕\mathrm{mK}$ at room temperature.