RESONANCE RAMAN AND INFRARED-SPECTROSCOPY OF CARBON NANOTUBUES

We present a comparative analysis of the vibrational and structural pr operties of carbon nanotubes. The first-order Raman spectrum exhibits two lines at 1582 cm-1 and at 1350 cm-1. The observed ratio of the int egrated intensity of these lines was found to be different as compared to polycrystalline graphite. The position and intensity of the line a round 1350 cm-1 strongly depend on the energy of the exciting laser li ne. This dispersion effect is again different from the dispersion in n anocrystalline graphite. It is discussed in terms of a photoselective resonance process. Transmission infrared spectra of the nanotubes show one broad and asymmetric line at 1575 cm-1 and a weaker line at 868 c m-1.