Electron-Deficient Eu6.5Gd0.5Ge6 Intermetallic: A Layered Intergrowth Phase of the Gd5Si4- and FeB-Type Structures

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• 作者：Jinlei Yao ; Peng Wang ; Yurij Mozharivskyj
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：March 5, 2012
• 年：2012
• 卷：51
• 期：5
• 页码：3172-3178
• 全文大小：448K
• 年卷期：v.51,no.5(March 5, 2012)
• ISSN：1520-510X

文摘

A novel electron-poor Eu_6.5Gd_0.5Ge₆ compound adopts the Ca₇Sn₆-type structure (space group Pnma, Z = 4, a = 7.5943(5) 脜, b = 22.905(1) 脜, c = 8.3610(4) 脜, and V = 1454.4(1) 脜³). The compound can be seen as an intergrowth of the Gd₅Si₄-type (Pnma) R₅Ge₄(R = rare earth) and FeB-type (Pnma) RGe compounds. The phase analysis suggests that the Eu_7鈥?i>xGd_xGe₆ series displays a narrow homogneity range of stabilizing the Ca₇Sn₆ structure at x 鈮?0.5. The structural results illustrate the structural rigidity of the ²[R₅X₄] slabs (X = p-element) and a possibility for discovering new intermetallics by combining the ²[R₅X₄] slabs with other symmetry-approximate building blocks. Electronic structure analysis suggests that the stability and composition of Eu_6.5Gd_0.5Ge₆ represents a compromise between the valence electron concentration, bonding, and existence of the neighboring EuGe and (Eu,Gd)₅Ge₄ phases.