Abstract
From second-order Raman scattering we find that the maximum in the phonon density of states of single-walled nanotubes softens by 30 over the value of graphite. A comparison of the phonon-dispersion curves of nanotubes in the literature shows that the ab initio approach best describes this softening. The excitation-energy dependence of the D and modes in single-walled nanotubes is 38 and 90 respectively, similar to the multiwalled species.
- Received 18 May 1999
DOI:https://doi.org/10.1103/PhysRevB.61.4542
©2000 American Physical Society