Electromagnetic properties of ion irradiated C60 films

The effects of ion irradiation on electrical and magnetic properties of C60 films are investigated and correlated to changes of structure. Conducting nanowires are formed along the linear path of swift heavy ions. Their continuity and radial dimension are correlated with the energy density deposited by such ions in electronic excitations. Whatever the slowing down process of ions, irradiation at high ion fluences induces the formation of an amorphous C phase exhibiting a ferromagnetic response up to room temperature. An additional paramagnetic signal is recorded from films irradiated with swift ions, which is ascribed to the formation of oriented defects decorated with oxygen.