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

Abstract

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 /-AlMnSi. The origin of the peak at Q = 1.62 A -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.

‘Cluster–disordered glue’ model for icosahedral quasicrystals

“…It is important to notice that orientational parallelism of the clusters in this model would produce Bragg-like peaks. But the random packing introduces unacceptably large unoccupied spaces in the structure, though these could be reduced [14]. The icosa-twinning model [15] is clearly incompatible with our positron annihilation results, since it is essentially based on the crystalline state itself.…”

Icosahedral clusters, icosaheral order and stability of quasicrystals—a view of metallurgy∗

“…This is in agreement with what we observed [51] in the growth process. By applying some modifications, Robertson and Moss extended the random cluster growth model and successfully explained the experimentally observed linear dependence on G ⊥ [52]. Therefore, the best model for describing the structure of the iQc is a modified icosahedral glass model.…”