NMR strategies to study the local magnetic properties of carbon nanotubes Auteur(s): Abou-Hamad E., Kim Y., Bouhrara M., Saih Y., Wagberg T., Luzzi D. E., Goze-Bac C. (Article) Publié: Physica B: Condensed Matter, vol. 407 p.740-742 (2012) Texte intégral en Openaccess : Ref HAL: hal-00745892_v1 DOI: 10.1016/j.physb.2011.12.012 WoS: 000301042700031 Exporter : BibTex | endNote 2 Citations Résumé: The local magnetic properties of the one dimensional inner space of the nanotubes are investigated using 13C nuclear magnetic resonance spectroscopy of encapsulated fullerene molecules inside single walled carbon nanotubes. Isotope engineering and magnetically purified nanotubes have been advantageously used on our study to discriminate between the different diamagnetic and paramagnetic shifts of the resonances. Ring currents originating from the π electrons circulating on the nanotube, are found to actively screen the applied magnetic field by −36.9 ppm. Defects and holes in the nanotube walls cancel this screening locally. What is interesting, that at high magnetic fields, the modifications of the NMR resonances of the molecules from free to encapsulated can be exploited to determine some structural characteristics of the surrounding nanotubes, never observed experimentally. |