Ion beam modification of fullerene films and their frictional behavior

C 60 films were deposited on a variety of substrates by thermal evaporation. The presence of C 60 in the films was confirmed by Transmission Electron Microscopy and Raman spectroscopic analysis. The C 60 films exhibited an average friction coefficient of 0.4–0.5. The films were irradiated with 2 MeV Ag + and B + ions at various doses. High energy ion bombardment created damage that resulted in partly crystalline to amorphous films, dependent on the mass and dose of ions. The amorphous films showed a friction coefficient of