THE ORIGIN OF LOCALIZED DIFFUSE-SCATTERING FROM ICOSAHEDRAL QUASI-CRYSTALS

Diffraction patterns from many different icosahedral quasicrystals exh ibit localized diffuse scattering that typically takes the form of par tial spherical shells in reciprocal space. Although many theoretical m odels for these shells have been proposed, none of these models adequa tely explains all the experimental observations. A new model based upo n local alpha-phase coordination of bonded Mackay clusters in the icos ahedral phase is presented. Diffraction simulations successfully predi ct most of the observed diffuse scattering features.