Pristine single-wall carbon nanotubes (SWCNT's) filled with C-60 are investigated with resonance Raman spectroscopy. Both totally symmetric modes of C-60 exhibit a surprising splitting into two components with a slightly different resonance behavior and an apparent loss of polarization. The latter can be understood from a symmetry reduction of the fullerene molecules in the center of the tubes and/or by an anisotropy of the electric field seen by the C-60 peas inside the SWCNT pods due to depolarization effects. The splitting is explained from molecular-dynamics simulations which show that the two bands emerge from a coupling of the C-60 totally symmetric modes to the fullerene translational mobility inside the tube. The doublet is thus the spectroscopic fingerprint of different mobilities of C-60 fullerenes in the tubes.
Electronic and mechanical coupling between guest and host in carbon peapods / Pfeiffer R; Kuzmany H; Pichler T; Kataura H; Achiba Y; Melle-Franco M; Zerbetto F. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 69:(2004), pp. 035404-035410. [10.1103/PhysRevB.69.035404]
Electronic and mechanical coupling between guest and host in carbon peapods
ZERBETTO, FRANCESCO
2004
Abstract
Pristine single-wall carbon nanotubes (SWCNT's) filled with C-60 are investigated with resonance Raman spectroscopy. Both totally symmetric modes of C-60 exhibit a surprising splitting into two components with a slightly different resonance behavior and an apparent loss of polarization. The latter can be understood from a symmetry reduction of the fullerene molecules in the center of the tubes and/or by an anisotropy of the electric field seen by the C-60 peas inside the SWCNT pods due to depolarization effects. The splitting is explained from molecular-dynamics simulations which show that the two bands emerge from a coupling of the C-60 totally symmetric modes to the fullerene translational mobility inside the tube. The doublet is thus the spectroscopic fingerprint of different mobilities of C-60 fullerenes in the tubes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.