Superstructure of Eu4Cd25:: A quasicrystal approximant
Superstructure of Eu4Cd25:: A quasicrystal approximant
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DOI：
10.1002/chem.200305463
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发表时间：
2004-07-05
影响因子：
4.3
通讯作者：
Lidin, S
中科院分区：
文献类型：
--
作者：
Gómez, CP;Lidin, S
合成了准晶体Eu_4Cd_25（以前称为EuCd_6），并用X射线单晶衍射对其进行了表征。在衍射数据中可以观察到对应于具有相对于I心立方子晶胞的加倍晶胞参数的F心立方晶胞的超结构反射。这给出了迄今为止报道的二元合金中最大的立方晶胞。新的超结构表现出的结构特征，发现在所有的RE-Cd-6近似，以及空/占用的Cd-8立方体和定向的Cd-4四面体，这导致超结构之间的进一步有序。用DSC观察到在782 K时的可逆高温相变。
The quasicrystal approximant Eu4Cd25, formerly designated EuCd6, was synthesized and characterized by means of single-crystal X-ray diffraction. Superstructure reflections corresponding to an F-centered cubic unit cell with a doubled cell-parameter relative to the I-centered cubic sub-cell could be observed in the diffraction data. This gives the largest cubic unit cell reported to date among binary alloys. ne superstructure exhibits structural features that are found in all the RE-Cd-6 approximants as well as a further ordering between vacant/occupied Cd-8 cubes and oriented Cd-4 tetrahedra, which causes the superstructure. A reversible high-temperature phase-transition was observed at 782 K by means of DSC.