2004/10/21 by Stefan Brühne, S. Bruehne, E. Uhrig +7
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Mineralogy and Gemology Studies #Quasicrystal Structures and Properties #X-ray Diffraction in Crystallography #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/0953-8984/17/10/011
published as J. Phys.: Condens. Matter 17 (2005) 1561-1572 · 12 pages, 8 figures, 2 tables
arxiv created 2004/10/21 · openalex publication_date 2005/02/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
A local and medium range atomic structure model for the face centred icosahedral (fci) Mg 25 Y 11 Zn 64 alloy has been established in a sphere of r = 27 Å. The model was refined by least squares techniques using the atomic pair distribution (PDF) function obtained from synchrotron powder diffraction. Three hierarchies of the atomic arrangement can be found: (i) five types of local coordination polyhedra for the single atoms, four of which are of Frank–Kasper type. In turn, they (ii) form a three-shell (Bergman) cluster containing 104 atoms, which is condensed sharing its outer shell with its neighbouring clusters, and (iii) a cluster connecting scheme corresponding to a three-dimensional tiling leaving space for a few glue atoms. Inside adjacent clusters, Y 8 cubes are tilted with respect to each other and thus allow for overall icosahedral symmetry. It is shown that the title compound is essentially isomorphic to its holmium analogue. Therefore, fci-Mg–Y–Zn can be seen as the representative structure type for the other rare earth analogues fci-Mg–Zn–RE (RE = Dy, Er, Ho, Tb) reported in the literature.