M3(Au,Ge)19 and M3.25(Au,Ge)18 (M = Ca, Yb): Distinctive Phase Separations Driven by Configurational Disorder in Cubic YCd6-Type Derivatives

被引：30

作者：

Lin, Oisheng ^{[1
]}

Corbett, John D. ^{[1
]}

机构：

[1] Iowa State Univ, Dept Chem, Ames, IA 50010 USA

来源：

INORGANIC CHEMISTRY | 2010年 / 49卷 / 10期

基金：

美国国家科学基金会;

关键词：

ICOSAHEDRAL QUASI-CRYSTAL; APPROXIMANTS; DISCOVERY; SYSTEM; SIZE;

D O I：

10.1021/ic100118q

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Exploratory syntheses in the M-Au-Ge (M = Ca, Yb) systems have led to the discovery of two cleanly separated non-stoichiometric phases M3Au similar to 14.4Ge similar to 4.6 (I) and M3.26Au similar to 12.7Ge similar to 5.3 (II), Single crystal X-ray studies reveal that both (space group Im (3) over bar) feature body-centered-cubic packing of five-shell multiply endohedral clusters that resemble those in the parent YCd6 (= Y3Cd18) and are akin to approximate phases in other quasicrystal systems. However, differences resulting from various disorders in these are distinctive. The innermost cluster in the M3Au similar to 14.4Ge similar to 4.6 phase (I) remains a disordered tetrahedron, as in the YCd6 parent. In contrast, its counterpart in the electron-richer M3.25Au similar to 12.7Ge similar to 5.3 phase (II) is a "rattling" M atom. The structural differentiations between I and II exhibit strong correlations between lattice parameters, cluster sizes, particular site occupancies, and valence electron counts,

引用

页码：4570 / 4577

页数：8

共 46 条

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