Comparative structural study of the disordered MCd6 quasicrystal approximants -: art. no. 024203

Several of the MCd6 approximants (M = Pr, Nd, Sm, Eu, Gd, Dy, Yb, Y, and Ca) to the MCd5.7 quasicrystals (M = Yb and Ca) have been synthesized and their structures have been refined from single-crystal x-ray-diffraction data; the different types of disorder of the central Cd-4 tetrahedra located in the dodecahedral cavities of these closely related compounds have been examined and mutually compared. A model that describes this disorder and can be applied to all the examined MCd6 phases has been elaborated. The refinements made on these phases differ from what is found in previous reports.