Synthesis, structural characterization and magnetic properties of RE₂MgGe₂ (RE=rare-earth metal)

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• 作者：Nian-Tzu Suen ; Paul H. Tobash ; Svilen Bobev  ; ;   ; ^{bobev@udel.edu}
• 关键词：Polar intermetallics ; Crystal structure ; Single-crystal X-ray diffraction ; Electronic structure calculations
• 刊名：Journal of Solid State Chemistry
• 出版年：2011
• 出版时间：November 2011
• 年：2011
• 卷：184
• 期：11
• 页码：2941-2947
• 全文大小：764 K

文摘

A series of rare-earth metal¨Cmagnesium¨Cgermanides RE₂MgGe₂ (RE=Y, Nd, Sm, Gd¨CTm, Lu) has been synthesized by reactions of the corresponding elements at high temperature. Their structures have been established by single-crystal and powder X-ray diffraction and belong to the Mo₂FeB₂ structure type (space group P4/mbm (No. 127), Z=2; Pearson symbol tP10). Temperature dependent DC magnetization measurements indicate Curie¨CWeiss paramagnetism in the high-temperature regime for all members of the family, excluding Y₂MgGe₂, Sm₂MgGe₂, and Lu₂MgGe₂. At cryogenic temperatures (ca. 60 K and below), most RE₂MgGe₂ phases enter into an antiferromagnetic ground-state, except for Er₂MgGe₂ and Tm₂MgGe₂, which do not undergo magnetic ordering down to 5 K. The structural variations as a function of the decreasing size of the rare-earth metals, following the lanthanide contraction, and the changes in the magnetic properties across the series are discussed as well.