title: Softening of the radial breathing mode in metallic carbon nanotubes.
abstract: The softening of the radial breathing mode (RBM) of metallic single walled carbon nanotubes (m-SWNTs) due to electron-phonon coupling has been studied by observing the Fermi level [see text] dependence of the RBM Raman peak. In situ Raman spectra were obtained from several individual m-SWNTs while varying [see text] electrochemically. The RBM frequency of an intrinsic m-SWNT is shown to be down-shifted relative to highly doped tubes by approximately 2 cm(1). The down-shift is greatest for small diameter and small chiral angle SWNTs. Most tubes show no change in RBM linewidth. A comparison is drawn between the RBM and the G band (A(LO) phonon) with respect to the [see text] dependence of their frequencies and linewidths.
authors.affiliation: Department of Materials Science and Engineering, MIT, Cambridge Massachusetts 02139, USA.
authors.forename: H
authors.initials: H
authors.lastname: Farhat
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
authors.forename: M
authors.initials: M
authors.lastname: Kalbac
authors.forename: M
authors.initials: M
authors.lastname: Hofmann
authors.forename: R
authors.initials: R
authors.lastname: Saito
authors.forename: M S
authors.initials: MS
authors.lastname: Dresselhaus
authors.forename: J
authors.initials: J
authors.lastname: Kong
mesh_terms: D055664:Electrochemical Techniques; D018020:Lithium Compounds / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D018020:Lithium Compounds; D037742:Nanotubes, Carbon; D011092:Polyethylene Glycols