Crystal Structure of the C-AlRuNi Phase
Crystal Structure of the C-AlRuNi Phase
复制标题
C-AlRuNi 相的晶体结构
DOI：
10.2320/matertrans.m2017106
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发表时间：
2017
影响因子：
1.2
通讯作者：
T. Kawamata
中科院分区：
文献类型：
--
作者：
R. Simura;K. Sugiyama;Shota Suzuki;T. Kawamata
C-AlRuNi的结构用单晶X射线衍射法测定（空间群Pm_3 ~（200））; α = 0.77088（4）nm; R = 0.0401（Fo > 2σ（Fo））。C-AlRuNi的基本结构可以用两种二十面体的堆积来解释。一种是过渡金属（TM; Ru和Ni）的正二十面体，中心TM原子位于1a位点（H-ICO），另一种是过渡金属（TM）的不规则二十面体，中心TM原子位于1b位点（HM-iICO）。一个H-ICO分别在两重轴和三重轴的方向上与六个H-ICO和八个HM-iICO接触。TM分布之间的间隙空间被Al原子填充。HM-iICO的内部是一个Al二十面体（Al-ICO），外部是一个大的Al立方体，H-ICO内部是一个小的Al立方体，外部是一个Al扭曲的二十面体，这表明HM-iICO的原子排列与pseudo-Mackay簇（pMC）有关。C-AlRuNi的结构也可以通过pMCs和AlICO团簇的CsCl样堆积来解释。pMC和Al-ICO是解释Al-TM-TM三元系中C1和C2相结构的关键团簇。[doi：10.2320/matertrans.M2017106]
The structure of C-AlRuNi was determined by single-crystal X-ray diffraction (space group Pm3̄ (No. 200); a = 0.77088(4) nm; R = 0.0401 for 268 independent re ections (Fo > 2σ(Fo)) measured by Mo Kα radiation). The fundamental structure of C-AlRuNi can be explained by the packing of two types of icosahedra. One is the regular icosahedron of transition metals (TMs; Ru and Ni) with a central TM atom at a 1a site (H-ICO), and the other is the irregular icosahedron of TMs with a central TM atom at a 1b site (HM-iICO). An H-ICO is in contact with six H-ICOs and eight HM-iICOs in the directions of the twofold and threefold axes, respectively. The interstitial spaces among the TM distribution are lled by Al atoms. An HM-iICO contains an Al icosahedron (Al-ICO) inside the HM-iICO and a large Al-cube outside of it. An H-ICO has a small Al-cube inside the H-ICO and an Al distorted icosidodecahedron outside of it, indicating the atomic arrangement associated with a pseudo-Mackay cluster (pMC). The structure of C-AlRuNi can also be explained by the CsCl-like packing of pMCs and AlICO clusters. The pMC and Al-ICO are the key clusters for explaining the structures of the C1 and C2 phases in the Al–TM–TM ternary system. [doi:10.2320/matertrans.M2017106]