Intermediate Frequency Raman Modes in Metallic and Semiconducting Carbon Nanotubes

Abstract

Resonance Raman spectra of bundled and isolated single‐wall carbon nanotubes (SWNTs) have been investigated in the spectral range between 600 and 1100 cm−1, associated with intermediate frequency modes (IFM). The IFMs have been poorly studied before despite the rich set of spectral features and their relation to defects and finite size effects in SWNTs. Different kinds of samples and many laser excitation energies (Elaser) have been used in the experiments. The differences in the IFM spectra for different SWNT samples are discussed, and from a line‐shape analysis of the spectra we get an (n,m) assignment based on IFM features.