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Title: Properties of K,Rb-intercalated C{sub 60} encapsulated inside carbon nanotubes called peapods derived from nuclear magnetic resonance

We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C{sub 60} encapsulated inside carbon nanotubes called peapods can be derived from {sup 13}C nuclear magnetic resonance investigations. Ring currents do play a basic role in those systems; in particular, the inner cavities of nanotubes offer an ideal environment to investigate the magnetism at the nanoscale. We report the largest diamagnetic shifts down to −68.3 ppm ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon intercalation. The metallization of intercalated peapods is evidenced from the chemical shift anisotropy and spin-lattice relaxation (T{sub 1}) measurements. The observed relaxation curves signal a three-component model with two slow and one fast relaxing components. We assigned the fast component to the unpaired electrons charged C{sub 60} that show a phase transition near 100 K. The two slow components can be rationalized by the two types of charged C{sub 60} at two different positions with a linear regime following Korringa behavior, which is typical for metallic system and allow us to estimate the density of sate at Fermi level n(E{sub F})
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Division of Physical Sciences & Engineering, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)
  2. Department of Chemistry, School of Science and Technology, Nazarbayev University, 010000 Astana, Republic of Kazakhstan (Kazakhstan)
  3. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)
  4. Department of Physics, Umeå University, 901 87 Umeå (Sweden)
  5. nanoNMRI Group, UMR5587, Université Montpellier II, Place E. Bataillon, 34095 Montpellier, Cedex 5 (France)
  6. KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)
Publication Date:
OSTI Identifier:
22489497
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARBON NANOTUBES; CHEMICAL SHIFT; CLATHRATES; FERMI LEVEL; FULLERENES; NUCLEAR MAGNETIC RESONANCE; PHASE TRANSFORMATIONS; RING CURRENTS; SPIN-LATTICE RELAXATION