Characterization of spatial correlations in carbon nanotubes-modelling studies

The Debye equation has been used to compute the powder diffraction patterns of single- and multiwalled carbon nanotubes. By generating Cartesian coord inates of atoms the models of non-chiral and chiral nanotubes of any shape and size have been constructed. An efficient algorithm has been developed t o calculate the kinematical diffraction profiles for the constructed models . The effect of curvature on the diffraction pattern has been examined by c omparison of the model-based simulations for various nanotubes and a single graphene laver. The applicability of the numerical procedure is illustrate d in the case of armchair, zig-zag and chiral nanotubes, both single and mu ltiwalled. The results of the computer simulations are compared with X-ray diffraction data, recorded for multiwalled nanotubes and published recently [Szczygielska et al., Acta Phys. Polon. A 98 (2000) 611]. (C) 2001 Elsevie r Science B.V. All rights reserved.