Scanning Tunneling Spectroscopy ofC36

Abstract

The local density of electronic states $N\left(E\right)$ has been measured on ${\mathrm{C}}_{36}$ thin films using scanning tunneling spectroscopy (STS). A 0.8 eV energy gap and sharp features in $N\left(E\right)$ with widths as small as 0.2 eV can be ascribed to the discrete molecular energy levels predicted for the ${\mathrm{C}}_{36}$ molecule, broadened by intermolecular interactions. However, a more complete agreement between the experimental results and theoretical predictions occurs if the system is modeled as covalently bonded ${\mathrm{C}}_{36}$ dimers and trimers. These results confirm the molecular nature of ${\mathrm{C}}_{36}$ as well as its higher reactivity as compared to larger size fullerenes.