Periodicity or quasiperiodicity in icosahedral Al-Mn phases?

摘要: Abstract Icosahedral alloys of the Al-(MnFeCr) system were studied using neutron diffraction and contrast variation effects. A method was developed to allow unambiguous determination amplitude phase shifts partial structure factors for measured pseudo-Bragg peaks. The three pair distribution functions also derived actual isomorphous substitution FeCr mixture Mn demonstrated. Manganese atoms found occupy about 85% vertices a 3D Penrose tiling with length 4.5 edges prolate rhombohedra. curious point is that Al lie on sublattice whose average distances coordination numbers seem mimic perfectly periodic cubic α-AlMnSi phase.