Experimental observation of individual single-wall nanotube species by Raman microscopy

Individual single-wall carbon nanotubes (SWNT) or small ropes of SWNTs with the same diameter have been characterised by Raman spectroscopy. Highly pu re, length-selected SWNTs adsorbed onto substrates designed for surface-enh anced Raman spectroscopy were investigated with a Raman microscope. Various spectra, each with a distinct sharp peak in the radial breathing mode area and four C-C stretching modes could be observed. The modes also showed a s trong variation in the relative intensities. In correlation with theoretica l predictions this should establish Raman microscopy as a non-destructive n ano-technological tool, capable of determining the diameter, symmetry and p osition of individual SWNTs. (C) 1999 Elsevier Science B.V. All rights rese rved.