Reinvestigation of the Uranium(3.5+) Rare-Earth Oxysulfides “(UO)2LnS3” (Ln = Yb, Y)

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• 作者：Geng Bang Jin ; Eun Sang Choi ; James A. Ibers
• 刊名：Inorganic Chemistry
• 出版年：2009
• 出版时间：September 7, 2009
• 年：2009
• 卷：48
• 期：17
• 页码：8227-8232
• 全文大小：796K
• 年卷期：v.48,no.17(September 7, 2009)
• ISSN：1520-510X

文摘

Dark-red square plates of the previously reported compounds “(UO)₂LnS₃” (Ln = Yb, Y) have been synthesized by solid-state reactions of UOS and YbS or Y₂S₃ with Sb₂S₃ as a flux at 1273 K. The structure of these isotypic compounds was reinvestigated by single-crystal X-ray diffraction methods and an inductively coupled plasma experiment. The actual formula of “(UO)₂LnS₃” (Ln = Yb, Y) is (U_0.5Ln_0.5O)₂LnS₃, that is, ULn₂O₂S₃, which can be charge-balanced with U⁴⁺ and Ln³⁺. The layered structure comprises (U/Ln)O₄S₄ square antiprisms alternating with LnS₆ octahedra. U and Ln1 atoms disorder on the eight-coordinate metal position, but Ln2 atoms occupy the six-coordinate metal position exclusively. UYb₂O₂S₃ is a modified Curie−Weiss paramagnet between 293 and 32 K, below which part of the paramagnetic moments go through a possible ferromagnetic transition. The band gaps of ULn₂O₂S₃ (Ln = Yb, Y) are around 2 eV.