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Title: The RELi{sub x}Sn{sub 2} (RE=La–Nd, Sm, and Gd; 0≤x<1) series revisited. Synthesis, crystal chemistry, and magnetic susceptibilities

This study is concerned with the ternary compounds RELi{sub x}Sn{sub 2} (RE=La–Nd, Sm, and Gd; 0≤x<1), which have been previously thought to be the stoichiometric RELiSn{sub 2} phases. These materials crystallize with the base-centered orthorhombic space group Cmcm (No. 63), and can be formally assigned with the CeNiSi{sub 2} structure type (Pearson symbol oC16). Our systematic single-crystal X-ray diffraction studies revealed substantial Li-deficiencies in all cases, with SmSn{sub 2} (space group Cmmm, ZrGa{sub 2} structure type, Pearson symbol oC12) and GdSn{sub 2} (space group Cmcm, ZrSi{sub 2} structure type, Pearson symbol oC12) being completely lithium-free. The structure refinements also uncovered positional disorder on the Sn site neighboring the vacancies. The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn{sub 2} and GdSn{sub 2} structures are devoid of any disorder. Temperature-dependent studies of the magnetic response of the title compounds are also presented and discussed. -- Graphical abstract: RELi{sub x}Sn{sub 2} (RE=La–Nd, 0≤x<1) crystallize in a defect variants of the CeNiSi{sub 2} structure type (a). The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn{submore » 2} (b) and GdSn{sub 2} (c) structures are devoid of any disorder. Highlights: • The crystal structures of the RELi{sub x}Sn{sub 2} (RE=La–Nd, 0≤x<1) compounds are revised using single-crystal X-ray diffraction data. • The structure is a filled derivative of the ZrSi{sub 2} structure type or defect variant of the CeNiSi{sub 2} structure type. • SmSn{sub 2} is isotypic with the ZrGa{sub 2} structure, while RESn{sub 2} (RE=Gd–Lu) are isotypic with the ZrSi{sub 2} structure.« less
Authors:
; ;  [1] ; ; ;  [2] ;  [1]
  1. Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States)
  2. Department of Physics, University of Maryland, College Park, MD 20742 (United States)
Publication Date:
OSTI Identifier:
22275852
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 211; Journal Issue: Complete; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DEFECTS; ELECTRONIC STRUCTURE; MAGNETIC SUSCEPTIBILITY; MONOCRYSTALS; ORTHORHOMBIC LATTICES; SPACE GROUPS; SYNTHESIS; TEMPERATURE DEPENDENCE; X-RAY DIFFRACTION; ZIRCONIUM SILICIDES