Changes in the crystal structure of multi-walled carbon nanotubes during high-energy electron irradiation (1.8MeV) to doses of between 3 and 10MGy were studied by analyzing Raman vibrational spectra. It was shown that the defects generated by electron beam irradiation were accompanied by an increase in interlayer correlations due to interlayer links and local variations in the geometry of multi-walled carbon nanotubes. The generation of structural defects led to a drop in the integral intensities of the G- and D-bands in the Raman scattering spectrum and to splitting of the G-band into several components. These results were supported by the appearance of new vibrational modes with an increase in irradiation fluence, indicating reconstruction of the structure and the geometry of the multi-walled nanotubes and of their symmetry.

Raman Vibrational Properties of Carbon Nanotubes with the Radiation Defect Formation. O.P.Dmytrenko, N.P.Kulish, N.M.Belyi, S.V.Lizunova, Y.I.Prylutskyy, L.Valkunas, R.Karpicz, V.V.Shlapatskaya, E.V.Prilutskiy, T.Wade, J.E.Wegrowe: Molecular Crystals and Liquid Crystals, 2008, 497, 38-45