Modifications of the C70 molecule (fullerene) under swift heavy ion irradiation are investigated. C70 thin films were irradiated with 120 MeV Au ions at fluences from 1 × 1012 to 3 × 1013 ions/cm2. The energetic ion impacts lead to the destruction of the C70 molecule. To investigate the stability of C70 fullerene, the damage cross-section and radius of the damaged cylindrical zones are evaluated by fitting the evanescence of C70 vibration modes recorded by Raman spectroscopy. Conductivity measurements together with Raman and optical absorption studies revealed that an irradiation fluence of 3 × 1013 ions/cm2 results in complete amorphization of the carbon structure of the fullerene molecules.
Swift heavy ion induced modifications of fullerene C70 thin films