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Infrared spectroscopy of single-walled carbon nanotubes
Auteur(s): Sbai K., Rahmani A., Chadli H., Bantignies J.-L., Hermet P., Sauvajol J.-L.
(Article) Publié:
The Journal Of Physical Chemistry B, vol. 110 p.12388-12393 (2006)
Texte intégral en Openaccess :
Ref HAL: hal-00514934_v1
PMID 16800564
DOI: 10.1021/jp0574504
WoS: 000238446900028
Exporter : BibTex | endNote
48 Citations
Résumé: By using the spectral moments method, we calculate the infrared spectra of chiral and achiral single-walled carbon nanotubes (SWCNTs) of different diameters and lengths. We show that the number of the infrared modes, their frequencies, and intensities depend on the length and chirality of the nanotubes. Furthermore, the dependence of the infrared spectrum as a function of the size of the SWCNT bundle is analyzed. These predictions are useful to interpret the experimental infrared spectra of SWCNTs.
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Use of resonance Raman spectroscopy to study the phase diagram of PbZr0.52Ti0.48O3
Auteur(s): Rouquette Jerome, Haines Julien, Bornand Véronique, Pintard Marie, Papet Philippe, Sauvajol J.-L.
(Article) Publié:
Physical Review B, vol. 73 p.224118 (2006)
Texte intégral en Openaccess :
Ref HAL: hal-00185225_v1
Ref Arxiv: 0711.0910
DOI: 10.1103/PhysRevB.73.224118
WoS: 000238696300033
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
37 Citations
Résumé: Evidence is presented for the first time that the sharp and continuous spectral changes observed in PbZr0.52Ti0.48O3 (PZT) between 350 and 10 K with the 647.1 nm wavelength are due to a resonance Raman effect. Such a phenomenon can be explained by means of a self-trapped exciton emission oxygen deficient complex (TiTi' - VO-) of PZT powder whose energy is close to the radiation line of the laser. This kind of approach should also be very useful to distinguish the phase transition sequence for other related ferro/ piezoelectric systems.
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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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Raman spectroscopy of free-standing individual semiconducting single-wall carbon nanotubes
Auteur(s): Paillet M., Langlois S., Sauvajol J.-L., Marty L., Iaia A., Naud C., Bouchiat V., Bonnot A.M.
(Article) Publié:
The Journal Of Physical Chemistry B, vol. 110 p.164-169 (2006)
Texte intégral en Openaccess :
Ref HAL: hal-00514938_v1
PMID 16471515
DOI: 10.1021/jp0516137
WoS: 000234520700032
Exporter : BibTex | endNote
9 Citations
Résumé: The radial breathing modes and tangential modes have been systematically measured on a large number of individual semiconducting single-wall carbon nanotubes (thin bundles) suspended between plots (free-standing single-wall carbon nanotubes). The strong intensity of the Raman spectra ensures the precision of the experimentally determined line shapes and frequencies of these modes. The diameter dependence of the frequencies of the tangential modes was measured. This dependence is discussed in relation with recent calculations. The present data confirm/contradict some previous interpretations.
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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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