Probing the single-wall carbon nanotube bundle: Raman scattering under high pressure

Citation
Ud. Venkateswaran et al., Probing the single-wall carbon nanotube bundle: Raman scattering under high pressure, PHYS REV B, 59(16), 1999, pp. 10928-10934
Citations number
25
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B-CONDENSED MATTER
ISSN journal
01631829 → ACNP
Volume
59
Issue
16
Year of publication
1999
Pages
10928 - 10934
Database
ISI
SICI code
0163-1829(19990415)59:16<10928:PTSCNB>2.0.ZU;2-2
Abstract
We report experimental and theoretical investigations on the pressure depen dence of the Raman-active radial and tangential vibrational modes of single -wall carbon-nanotube bundles. Using 514.5-nm excitation, we find that the radial mode intensity disappears beyond 1.5 GPa, and the tangential mode in tensity also drops considerably above this pressure. This observation is te ntatively attributed to a loss in the electronic resonance in the Raman sca ttering cross section due to a hexagonal distortion in the cylindrical cros s section of the tubes in the bundles under compression. Theoretical calcul ations were made as a function of pressure using a generalized tight-bindin g molecular dynamics scheme that included intertubule van der Waals couplin g. Under certain model assumptions, the experimental pressure dependence of the radial mode is well described by the calculations, indicating that int ertubule interactions strongly influence the ambient pressure frequency and the pressure behavior of the radial breathing mode. [S0163-1829(99)11115-9 ].