Characteristic Raman spectra of multiwalled carbon nanotubes

Highly graphitized multiwalled carbon nanotubes (MWNTs) with very thin inner diameter of similar to 1 nm, which were prepared by hydrogen arc discharge, were studied by using micro, polarized, resonance and surface-enhanced Raman scattering techniques. The radial breathing modes originating from very thin core nanotubes in MWNTs were observed. The multiple splitting of graphite-like G mode of MWNTs as also found in the surface-enhanced Raman spectra of isolated MWNTs. Thus, MWNTs prepared by hydrogen arc discharge possess characteristic Raman spectral features. (C) 2002 Elsevier Science B.V. All rights reserved.