Detailed structures of (Al, Zn)(49)Mg-32-type crystalline phases, which are
closely related to the Mg-Al-Zn icosahedral quasicrystal in Mg40Al60-xZnx
(x=14-51) alloys, were examined by single-crystal X-ray diffraction analysi
s. The structures have been determined with final R factors less than 0.04,
and show good correspondence between chemical compositions obtained from s
tructural refinements and those determined by electron probe microanalysis.
The refined structures are somewhat different from that proposed by Bergma
n et al. [G. Bergman, J.L.T. Waugh, L. Pauling, Acta Crystallogr. 10 (1957)
254] in that they have no central atom in the Bergman-type atom cluster. T
he atom site occupancy is also discussed as a function of Zn content. (C) 2
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