Crystal structure of μ7-MgZnSm
1999; Elsevier BV; Volume: 285; Issue: 1-2 Linguagem: Inglês
10.1016/s0925-8388(98)01048-2
ISSN1873-4669
AutoresKazumasa Sugiyama, Kenichi Yasuda, Y. Horikawa, Tetsu Ohsuna, Kenji Hiraga,
Tópico(s)X-ray Diffraction in Crystallography
ResumoThe structure of hexagonal μ7-MgZnRE phase Mg24.1Zn64.8Sm11.1 was determined by single crystal X-ray structural analysis: P63/mmc (No. 194), a=33.565(2) Å, c=8.873(2) Å, atoms/cell=480, F(000)=14016, μ=30.11 mm−1, Dcalc=5.973 Mg/m−3, R=0.0376 for the observed 1733 reflections with Fobs>4.0σ(Fobs). The structure of μ7-MgZnRE is closely related to that of μ3-MgZnSm (P63/mmc, a=14.619 Å, c=8.708 Å) and the MgZn2 Laves phase (P63/mmc, a=5.223 Å, c=8.566 Å). The introduction of Sm increases the distortion of the icosahedral atomic arrangement around Zn and this produces a variety of icosahedral linkages in μ-phases. The structural units of icosahedral columns are introduced for demonstrating the crystalline structures of μ-phases.
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