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

Journal Article · Sat Mar 15 04:00:00 EDT 2014 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2013.12.010· OSTI ID:22275852

Makongo, Julien P.A.; Suen, Nian-Tzu; Guo, Shengping ^[1]; Saha, Shanta; Greene, Richard; Paglione, Johnpierre ^[2]; Bobev, Svilen ^[1]

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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)

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{sub 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.

• OSTI ID: 22275852
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: Complete Vol. 211; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

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