Origin of the low-frequency band in Raman spectra of multi-walled carbon nanotubes synthesized by the CVD method

Abstract

The origin of the low-frequency band (250–300 cm−1) in the Raman spectra of multi-walled carbon nanotubes (MWCNTs) produced by the CVD method has been studied. The studies performed by Raman spectroscopy, transmission electron microscopy, Auger spectroscopy, and X-ray photoelectron spectroscopy after chemical and thermal treatments allow the assumption that this band belongs to radial vibrations of carbon atoms in internal walls of MWCNTs.