Composition dependence of the atomic structure of . . - Al Mg Zn - (20 5 x 50 5) 1/1 1/1 1/1 x 39 . 5 60 . 5 x approximants determined by the Rietveld method
Composition dependence of the atomic structure of . . - Al Mg Zn - (20 5 x 50 5) 1/1 1/1 1/1 x 39 . 5 60 . 5 x approximants determined by the Rietveld method
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的原子结构的成分依赖性。
DOI：
10.1080/095008397178959
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发表时间：
1997
影响因子：
1.2
通讯作者：
T. Takeuchi
中科院分区：
文献类型：
--
作者：
U. Mizutani;W. Iwakami;T. Takeuchi
用Rietveld方法测定了Al Mg Zn（20.5 × 50.5）1/1- 1/1 -x39.0 60.5-x1/1近似物的原子结构与Al浓度x的关系。通过使用Bergman等人的数据完成了改进。作为起始参数。它示出的簇的中心是由Al原子在x = 20.5仅占10%，但当x超过30时变得基本上是空的。在第一壳层中的二十面体簇的顶点所对应的站点被Zn原子占据80%，并且在浓度范围x 40中由Al原子占据其余站点。我们还指出，从铝浓度依赖的各种原子对的原子间距离，自由电子类键合机制占主导地位的Al-Mg-Zn近似。这是与以前的电子结构的研究，目前的近似。
The atomic structure of the Al Mg Zn (20.5 x 50.5) 1/1- 1/1 - x 39.0 60.5- x 1 /1 approximants has been determined as a function of the Al concentration x by applying the Rietveld method to the X-ray powder diffraction data. The refinement was accomplished by using the data due to Bergman et al . as starting parameters. It is shown that the centre of the cluster is only 10% occupied by the Al atom at x = 20.5 but becomes essentially vacant when x exceeds 30. The sites corresponding to the vertex of the icosahedral cluster in the first shell are 80% occupied by the Zn atoms and the remaining sites by the Al atoms in the concentration range x 40. We also point out, from the Al concentration dependence of the interatomic distance of various atomic pairs, that the freeelectron-like bonding mechanism dominates the Al-Mg-Zn approximants. This is consistent with previous studies of the electronic structure for the present approximants.