Discriminated structural behaviour of and peapods under extreme conditionsM. Chorro1, J. Cambedouzou1, A. Iwasiewicz-Wabnig2, L. Noé3, S. Rols4, M. Monthioux3, B. Sundqvist2 and P. Launois1
1 Laboratoire de Physique des Solides UMR-8502 CNRS, Université Paris-Sud - F-91405 Orsay, France
2 Department of Physics, Umeå University - S-90187 Umeå, Sweden
3 Centre d' Elaboration des Matériaux et d'Etudes Structurales, UPR-8011 CNRS - F-31062 Toulouse, France
4 Institut Laue Langevin - F-38042, Grenoble, France
received 12 June 2007; accepted in final form 6 July 2007; published September 2007
published online 2 August 2007
We studied structural changes in C60 and C70 peapods -i.e. C60 and C70 chains inserted inside single-walled carbon nanotubes- when submitted to high pressure and temperature conditions. X-ray diffraction experiments showed that while C60 molecules polymerize inside nanotubes at pressures and temperatures consistent with polymerization in bulk C60 phases, no polymerization is observed in C70 peapods, even at pressures and temperatures above the threshold for polymerization in bulk C70. Tubular confinement in the nanotube container prevents the monomers to rearrange in the way needed for polymerization. This result testifies for the strong influence of confinement on the behaviour of C70.
61.48.+c - Fullerenes and fullerene-related materials.
07.35.+k - High-pressure apparatus; shock tubes; diamond anvil cells.
61.46.Fg - Nanotubes.
© Europhysics Letters Association 2007