Raman scattering from double‐walled carbon nanotubes

Abstract Raman scattering from double‐walled carbon nanotubes is reported with particular emphasis on the response from the radial breathing mode (RBM) of the inner‐shell tubes. The unexpected large number of very narrow lines observed is explained by the growth of one and the same inner tube type in different outer tubes in a highly shielded environment. The response of the RBM and of the G‐line is used to analyze the transition from peapods to double‐walled carbon nanotubes. During the transformation process the Raman response disappears for a short time, indicating the existence of some Raman dark matter. By preparing the starting peapods from heterofullerenes such as (C 59 N) 2 or 13 C‐substituted fullerenes, hetero‐nanotubes can be grown where nitrogen or the 13 C atoms are incorporated into the inner tube wall. Copyright © 2007 John Wiley & Sons, Ltd.