Atomic decoration of a random-cluster model for icosahedral-phase AlMnSi

Preliminary results on the atomic decoration of a random-cluster model for icosahedral-phase alloys are presented. The calculated neutron and x-ray intensities compare quite favorably with experimental intensity data on i-AlMnSi. The origin of the peak at Q=1.62 A${\mathrm{̊}}^{\mathrm{-}1}$, associated with the prepeak found in ‘‘amorphous’’ AlMnSi, as well as the ubiquitous ‘‘diffuse’’ scattering, seen experimentally under the groups of strong peaks in all icosahedral-phase alloys, are revealed selectively in the calculated partial intensities for Al-Al, Al-Mn, and Mn-Mn correlations.