Disorder diffuse scattering of decagonal quasicrystals

Diffuse scattering in decagonal phases is due to deviations from strict aperiodic and periodic order in the quasiperiodic plane and along the unique direction, respectively. Results from X-ray (synchrotron) and neutron diffraction experiments, mainly carried out with decagonal Al-Ni-Co, are presented. Most prominent are diffuse maxima, diffuse streaks, phason affected reflection profiles, and diffuse layers perpendicular to the unique axis. Disorder models in decagonal qc-structures, in particular lamellar domain-like ordering in super-space are outlined. The terms structure and phase in context with disordered structures are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.