Thermal conductivity of single crystalC60

Abstract

We report the first measurement of the thermal conductivity of single crystal ${\mathrm{C}}_{60}$. We observe that orientational disorder significantly reduces the thermal conductivity, evidenced by a large jump in the thermal conductivity at the 260 K orientational-order transition. The temperature and time dependences of the thermal conductivity below 260 K are shown to be described by a phenomenological model that involves thermally activated jumping motion between two nearly degenerate orientations, separated by an energy barrier of ∼260 meV.