Controlled high-current-induced scanning tunnelling microscope modification of C₆₀

We demonstrate controlled STM-induced modification/destruction of I_h-C₆₀ supported on a Cu(111) surface, showing that the molecule is more resilient to high currents for bias voltages greater than ca. 3.5 V. This is due to the enhanced charge transport through the diffuse SAMO orbitals of the molecule with lower probability for electron-vibration coupling than found for resonant low bias transport through π-molecular orbitals. Experimental and theoretical DFT results demonstrate the destruction mechanism comes from C₂ emission from the fullerene cage and the formation of smaller fullerenes via sequential emission of C₂.