Abstract Submitted to the    NANOTUBE'04 Conference:

High quality double-wall carbon nanotubes (DWNTs), which were synthesized by the high-temperature pulsed-arc discharge (HTPAD) method, have characterized by resonant Raman spectroscopy employing various excitation laser lines (photon energy 1.8-2.8 eV). RBM, D-band, G-band and G'-band have shown salient photon energy dependence. Two distinct peaks for G'-band were observed around 2,450 and 2,650 cm-1. These two peaks have exhibited different dependence on excitation energy. Theoretical considerations indicate that one stems from non-dispersive of phonon frequency and the other from dispersive processes. In fact, experimental results were good agreement with calculation. Such features were also obtained for SWNTs and HOPG.