title: Anisotropic packing and one-dimensional fluctuations of C60 molecules in carbon nanotubes.
abstract: The confinement of a C60 molecule encapsulated in a cylindrical nanotube depends on the tube radius. In small tubes with radius RT approximately < 7 A, a fivefold axis of the molecule coincides with the tube axis. The interaction between C60 molecules in the nanotube is then described by a O2-rotor model on a 1D liquid chain with coupling between orientational and displacive correlations. This coupling leads to chain contraction. The structure factor of the 1D liquid is derived. In tubes with a larger radius the molecular centers of mass are displaced off the tube axis. The distinction of two groups of peapods with on- and off-axis molecules suggests an explanation of the apparent splitting of Ag modes of C60 in nanotubes measured by resonant Raman scattering.
authors.affiliation: Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: K H
authors.initials: KH
authors.lastname: Michel
authors.forename: B
authors.initials: B
authors.lastname: Verberck
authors.forename: A V
authors.initials: AV
authors.lastname: Nikolaev