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Mg 1– y Sc y Zn 2 : Limited Sc/Mg Alloying between Laves Phase MgZn 2 and ScZn 2 – What Drives ScZn 2 into a High‐Pressure Phase?
Author(s) -
Wang Wenliang,
Chen Guihuan,
Wang Yixiu,
Lin Qisheng
Publication year - 2011
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201100319
Subject(s) - chemistry , isostructural , antibonding molecular orbital , laves phase , crystallography , bond length , fermi level , lattice constant , stoichiometry , analytical chemistry (journal) , diffraction , crystal structure , intermetallic , physics , quantum mechanics , organic chemistry , alloy , chromatography , atomic orbital , optics , electron
A series of solid solutions between the MgZn 2 and ScZn 2 isostructural Laves phases at 400 °C was synthesized by fusion of stoichiometric metals by conventional solid‐state high‐temperature means. X‐ray diffraction analyses revealed that the alloys remain in space group P 6 3 / mmc , with a = 5.228–5.249 Å and c = 8.532–8.487 Å. The lattice parameters of the solid solution exhibit anisotropic variations: a increases and c decreases with increased starting Sc content ( x ) inMg 1– x Sc x Zn 2 . The anisotropic changes correspond to the variations of bond lengths in the ab plane and the interlayer bonds in c . Under the applied reaction conditions, the maximum Sc content was estimated to be y max ≈ 0.47–0.50 in the formula of Mg 1– y Sc y Zn 2 . Theoretical calculations on a hypothetical ScZn 2 model extrapolated for normal pressure revealed that it had higher density‐of‐states (DOS) and evident Zn–Zn antibonding states at the Fermi energy, meaning that high pressure is necessary to counteract the internal stress resulting from antibonding states.