title: Electronic structures of single-walled carbon nanotubes determined by NMR
abstract: Single-walled carbon nanotubes were studied by (13)C nuclear magnetic resonance (NMR). Two types of (13)C nuclear spins were identified with different spin-lattice relaxation rates. The fast-relaxing component, assigned to metallic tubes, followed the relaxation behavior expected in metals, and the density-of-states at the Fermi level increased with decreasing tube diameter. The slow-relaxing component has a significantly lower density-of-states at the Fermi level. Exposure to oxygen has a substantial effect on relaxation rates of both components.
authors.affiliation: Department of Physics and Astronomy and Curriculum in Applied and Materials Sciences, University of North Carolina, Chapel Hill, NC 27599-3255, USA.
authors.initials: X
authors.lastname: Tang
authors.initials: A
authors.lastname: Kleinhammes
authors.initials: H
authors.lastname: Shimoda
authors.initials: L
authors.lastname: Fleming
authors.initials: KY
authors.lastname: Bennoune
authors.initials: S
authors.lastname: Sinha
authors.initials: C
authors.lastname: Bower
authors.initials: O
authors.lastname: Zhou
authors.initials: Y
authors.lastname: Wu