Raman characterization of aligned carbon nanotubes produced by thermal decomposition of hydrocarbon vapor

Raman characterization of aligned carbon nanotubes of average diameter 10–15 nm, produced by chemical vapor deposition on a mesoporous substrate, has been carried out. The resonance behavior and higher-order Raman bands up to fourth order have been observed and compared with those of carbon nanotubes produced by arc discharge and highly oriented pyrolytic graphite, as well as pyrolytic graphite. The phonon properties have been analyzed with the help of high-resolution transmission electron microscope studies.