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(93) Production(s) de MICHEL T.
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E S33 and E S44 Optical Transitions in SWNT : Raman and Electron Diffraction Experiments
Auteur(s): Michel T.
Conference: GDRE Nano-E Topical Meeting on Optical Properties of Carbon Nanotubes (Paris, France, FR, 2007-05-25)
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Spectroscopie Raman de nanotubes de carbone métalliques individuels suspendus et sur substrat
Auteur(s): Michel T.
(Affiches/Poster)
GDRE Nanotubes (Grenoble, France, FR), 2007-10-15 |
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Raman active phonons of identified semiconducting single walled-carbon nanotubes 
Auteur(s): Paillet M., Michel T., Meyer C., Roth S., Popov V., Henrard L., Sauvajol J.-L.
(Article) Publié:
Physical Review Letters, vol. 96 p.257401-1-4 (2006)
Ref HAL: hal-00514936_v1
PMID 16907341
DOI: 10.1103/PhysRevLett.96.257401
WoS: 000238697000053
Exporter : BibTex | endNote
71 Citations
Résumé: The resonant Raman spectra of (n,m) semiconducting single-walled carbon nanotubes, unambiguously identified from their electron diffraction patterns, have been measured. The diameter dependence of the frequency of the tangential modes with A symmetry has been obtained in the diameter range from 1.4 to 2.5 nm. The comparison between the excitation energies and the calculated transition energies allowed us to determine precisely the values of the Es33 and Es44 transition energies. Finally, in the debate concerning the dominant process at the origin of the first-order Raman scattering in single-walled carbon nanotubes (single resonance process or double resonance process), our results are well understood in the framework of a single resonance process.
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Selecte growth of large chiral angle single-walled carbon nanotubes
Auteur(s): Paillet M., Meyer J.C., Michel T., Jourdain V., Poncharal Philippe, Sauvajol J.-L., Cordente N., Amiens C., Chaudret B., Roth S., Zahab A. A.
(Article) Publié:
Diamond And Related Materials, vol. 15 p.1019-1022 (2006)
Ref HAL: hal-00514937_v1
Exporter : BibTex | endNote
Résumé: We have developed a versatile catalyst-assisted chemical vapor deposition (CVD) technique for the synthesis of single-walled carbon nanotubes (SWNTs) from discrete nickel nanoparticles (average diameter of 4.7 ± 1.5 nm). Atomic force microscopy (AFM), transmission electron microscopy (TEM) and electron diffraction are used to characterize these as-grown nanotubes. On a particular sample we found that the SWNTs have an average chiral angle of 25.3°. This result shows that a control of the chiral angle of SWNT with large diameters (mean diameter = 1.75 nm) and with a relatively broad diameter distribution (standard deviation = 0.5 nm) is achievable to a certain extent.
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Structural selective charge transfer in iodine-doped carbon nanotubes
Auteur(s): Michel T., Alvarez L., Sauvajol J.-L., Almairac Robert, Aznar R., Mathon O., Bantignies J.-L., Flahaut Emmanuel
(Article) Publié:
Journal Of Physics And Chemistry Of Solids, vol. vol. 67 n° 5-6. p.1190-1192 , available on http://oatao.univ-toulouse.fr/744/1/flahaut_744.pdf (2006)
Ref HAL: hal-00474864_v1
Exporter : BibTex | endNote
Résumé: We have investigated iodine intercalated carbon nanostructures by extended X-ray absorption fine structure (EXAFS) and Raman spectroscopies. We discuss here the charge transfer and the iodine–carbon interaction as a function of the carbon nanostructures (graphite, multi-walled, double-walled and single walled nanotubes). The results show that iodine is weakly adsorbed on the surface of all multi-walled nanotubes. By contrast, a charge transfer between iodine and single walled nanotubes is evidenced.
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EXAFS investigations of iodine-doped carbon nanotubes
Auteur(s): Michel T., Alvarez L., Sauvajol J.-L., Almairac Robert, Aznar R., Bantignies J.-L., Mathon O.
(Article) Publié:
Physical Review B, vol. 73 p.195419 (2006)
Ref HAL: hal-00498071_v1
Exporter : BibTex | endNote
Résumé: We report an x-ray absorption fine structure study at the iodine-K edge of the local structure in iodine-doped carbon nanotubes. The iodine-carbon host interaction is shown to be weaker in multiwalled carbon nanotubes (MWNTs) than in single-walled carbon nanotubes (SWNTs). Iodine species are only localized at the surface of the external tube for MWNTs, whereas iodine species enter inside SWNTs. For doped SWNTs, both the experimental and the theoretical EXAFS spectra allow us to establish the structure of the iodine chain as disordered pentaiodide at the saturation level.
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Est-il possible de discerner le caractère métallique d'un nanotube individuel par spectroscopie RAMAN?
Auteur(s): Michel T.
Conference: Journée de la matière condensée (Toulouse, France, FR, 2006-08-28)
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