Correlations between Chemical Bonding and Magnetic Exchange Interactions: Synthesis, Crystal Structures, and Magnetic Properties of the New Family RE2AlGe2 (RE = Tb鈥揟m, Lu)

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• 作者：Jiliang Zhang ; Svilen Bobev
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：May 6, 2013
• 年：2013
• 卷：52
• 期：9
• 页码：5307-5315
• 全文大小：515K
• 年卷期：v.52,no.9(May 6, 2013)
• ISSN：1520-510X

文摘

Six new rare-earth metal germanides with general formula RE₂Al_1鈥?i>xGe_2+x (RE = Tb鈥揟m, Lu; 0.13(2) 鈮?x 鈮?0.37(2)) have been synthesized by direct fusion of the corresponding elements. Their structures have been established by single-crystal diffraction to crystallize with the orthorhombic space group Immm (no. 74), adopting the W₂CoB₂ structure type. The Al and Ge atoms are arranged in alternating planar layers, made of rhombic- and hexagonal-fragments. The rare-earth metal substructure consists of puckered four-connected nets. Electronic structure calculations support the coloring of the Ge and Al sites and account for the existence of a small homogeneity range. DC magnetization measurements for all specimens are also presented; based on the RKKY and mean-field theories for antiferromagnets, relationships between the chemical bonding and exchange interactions are discussed.