LANTHANIDE-COPPER INTERMETALLIC COMPOUNDS HAVING THE CeCu$sub 2$ AND AlB$sub 2$ STRUCTURES
LANTHANIDE-COPPER INTERMETALLIC COMPOUNDS HAVING THE CeCu$sub 2$ AND AlB$sub 2$ STRUCTURES
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DOI：
10.1107/s0365110x6300181x
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发表时间：
1963-07
期刊：
影响因子：
--
通讯作者：
A. R. Storm;K. E. Benson
中科院分区：
文献类型：
--
作者：
A. R. Storm;K. E. Benson
Twelve rare-earth--copper intermetallic compounds (XCu2, X= rare earth metal) have been prepared as part of a continuing study of the properties of rare earth alloys. From powder X-ray data only, it has been shown that all of these alloys, as well as YCu2 are orthorhombic and isostructural with CeCuv The structure of CeCu~ was recently reported by Larson and Cromer (1961). The CeCue structure belongs to space group Imma 2s! _~!(D~ h) with Ce in positions 4e:(000; u 22 J+ 0, ¼, z; 0,~, 5; and Cu in positions 8h:(000;~-21~ x~ 2,+ 0, y, z; 0,~, 2; 0, ½+ y, 5; 0, ½, z. Larson and Cromer found the value of z for Ce to be 0.5377±0.0006 while for Cu, y= 0.0510±0.0011 and z= 0.1648±0.0010. We have shown from powder X-ray data only that LaCu2 has the hexagonal A1B2 structure. The existence of a compound with this stoichiometry has been reported previously (Gschneider, 1961) but without crystal structure data. In this investigation it was found that 25-g ingots almost completely oxidize in air in a day and X-ray patterns must be taken soon after preparation. This relatively rapid oxidation could possibly account for the lack of structure data from previous investigators.
