Strong electronic excitation effect of swift heavy ions on C-60 films

Strong electronic excitation effect of C-60 films induced by 2.0 GeV Xe-136 and 2.7GeV U-238 ions was investigated by means of Fourier transform infrared (FTIR), Raman Scattering and X-ray diffraction (XRD) spectroscopies. A new peak located at 670 cm(-1), which corresponds to an unknown structure, was observed in the FTIR spectra of C-60 films irradiated for the first time. The variation in intensity of 670 cm-1 peak with electronic energy loss and irradiation dose were studied. The analysis results indicated that electronic energy transfer dominates the damage process of C-60 films. The partial recovery of the damage in irradiated C-60 films at middle electronic energy loss is attributed to an annealing effect of the strong electronic excitation. The ion velocity also plays a role in the process of the damage creation.