The vibrational modes of some single-wall C nanotube intramolecular junctions were calculated using the latest Brenner reactive empirical bond order potential, based on which their non-resonant Raman spectra were further calculated using the empirical bond polarizability model. It was found that the Raman peaks induced by pentagon defects lay outside of the G-band of the single-wall C nanotubes; thus, the high-frequency part of the Raman spectra of the single-wall C nanotube intramolecular junctions could be used to experimentally determine their detailed geometrical structures. Also, the intensity of the Raman spectra has a close relation with the number of pentagon defects in the single-wall C nanotube intramolecular junctions. Following the Descartes-Euler polyhedral formula, the number of heptagon defects in the single-wall C nanotube intramolecular junctions could also be determined. The first-principles calculations were also performed, verifying the results obtained by the reactive empirical bond order potential. The G band width of the single-wall C nanotube intramolecular junction could reflect the length of its transition region between the pentagon and heptagon rings.

Raman Characteristic Peaks Induced by the Topological Defects of Carbon Nanotube Intramolecular Junctions. G.Wu, J.Dong: Physical Review B, 2006, 73[24], 245414 (9pp)