Crystal structure of the monoclinic η-Al₁₁Cr₂

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• 作者：B.B. Cao ; K.H. Kuo
• 关键词：Intermetallics ; Crystal structure ; X-ray diffraction
• 刊名：Journal of Alloys and Compounds
• 出版年：2008
• 出版时间：30 June 2008
• 年：2008
• 卷：458
• 期：1-2
• 页码：238-247
• 全文大小：1549 K

文摘

The crystal structure of the monoclinic phase η-Al₁₁Cr₂ of the space group C2/c, a ≈ 1.76 nm, b ≈ 3.05 nm, c ≈ 1.76 nm, β ≈ 90° [L.A. Bendersky, R.S. Roth, J.T. Ramon, D. Shechtman, Metall. Trans. A 22A (1991) 5] has been determined by single-crystal X-ray diffraction. The structure model, refined to a final R value of 0.0441, has the composition of Al_83.8Cr_16.2. a = 1.77348(10) nm, b = 3.04555(17) nm, c = 1.77344(10) nm, monoclinic angle β = 91.0520(12)°. There are 80 (66Al + 14Cr) independent atomic positions in a unit cell, of which all Cr atom sites and 8 Al atom sites have icosahedral coordination. These icosahedra are interconnected forming icosahedral chains along , (1 0 1) icosahedral layer blocks as well as a three-dimensional icosahedral structure.