%0 Journal Article
%T Molecular Dynamics and Phase Transition in One-Dimensional Crystal of C-60 Encapsulated Inside Single Wall Carbon Nanotubes
%+ Laboratoire des colloïdes, verres et nanomatériaux (LCVN)
%A Abou-Hamad, E.
%A Kim, Y.
%A Wagberg, T.
%A Boesch, D.
%A Aloni, S.
%A Zettl, A.
%A Rubio, A.
%A Luzzi, D. E.
%A Goze-Bac, Christophe
%< avec comité de lecture
%Z LCVN:09-049
%@ 1936-0851
%J ACS Nano
%I American Chemical Society
%V 3
%P 3878-3883
%8 2009
%D 2009
%R 10.1021/nn901128t
%K carbon nanostructures
%K dynamical properties
%K phase transition
%K nuclear magnetic resonance
%K SOLID C60
%K STATE
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]
%Z Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph]Journal articles
%X One-dimensional crystals of 25% C-13-enriched C-60 encapsulated inside highly magnetically purified SWNTs were investigated by following the temperature dependence of the C-13 NMR line shapes and the relaxation rates from 300 K down to 5 K. High-resolution MAS techniques reveal that 32% of the encapsulated molecules, so-called the C-60(alpha), are blocked at room temperature and 68%, labeled C-60(beta), are shown to reversly undergo molecular reorlentational dynamics. Contrary to previous NMR studies, spin - lattice relaxation time reveals a phase transition at 100 K associated with the changes in the nature of the C-60(beta) dynamics. Above the transition, the C-60(beta) exhibits continuous rotational diffusion; below the transition, C-60(beta) executes uniaxial hindered rotations most likely along the nanotubes axis and freeze out below 25 K. The associated activation energies of these two dynamical regimes are measured to be 6 times lower than in fcc-C-60, suggesting a quiet smooth orientational dependence of the interaction between C-60(beta) molecules and the inner surface of the nanotubes.
%G English
%L hal-00503215
%U https://hal.science/hal-00503215
%~ CNRS
%~ UNIV-MONTP2
%~ LCVN
%~ UNIV-MONTPELLIER
%~ UM1-UM2