Radiation damage to multi-walled carbon nanotubes and their Raman vibrational modes

The influence of the radiation damage to multi-walled carbon nanotubes (MWCNT) during the high-energy electron irradiation (E-e = 1.8 MeV) with different doses of absorption (D-n = 0.5; 1.0; 1.5 and 2.0 MGy) on their Raman vibrational spectra is studied in detail. The modification of both radial and tangential optical vibrations is observed depending on radiation dose. This is manifested both in the frequency shifts of the vibrational modes and in a change in the intensity of the Raman scattering, which corresponds to different optical vibrations. This behavior of Raman spectrum is explained by appearance and increase in the concentration of radiation defects and by seams of separate layers of nanotubes. (c) 2006 Elsevier Ltd. All rights reserved.