We report a study of second-order combination and overtone modes in highly ordered pyrolytic graphite (HOPG), in single-wall carbon nanotube (SWNT) bundles and in isolated SWNTs. We found both dispersive and nondispersive Raman bands in the range 1650-2100 cm-1, and we show that the appearance and frequency versus laser energy Elaser behavior of these features are in agreement with predictions from double-resonance Raman theory. In the case of SWNTs, these second-order bands depend on the one-dimensional structure of SWNTs, and at the single nanotube level, the spectra vary from tube to tube, depending on tube diameter and chirality and on the energy of the van Hove singularity relative to Elaser.
|Number of pages||13987630|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2002 Oct 15|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics