Intermetallic compounds in the M–Cu–Sn systems with M = Eu, Sr, Ba

• Published in: Intermetallics 2011-07, Vol.19 (7), p.957-963
• Main Authors: Pani, M., Fornasini, M.L., Manfrinetti, P., Merlo, F.
• Format: Article
• Language: English
• Subjects: A. Rare-earth intermetallics; Annealing; B. Crystal chemistry of intermetallics; B. Phase identification; Beta; Crystal structure; F. Diffraction; Intermetallics; Melting; Phases; Rietveld method; Strontium
• ISSN: 0966-9795; 1879-0216
• DOI: 10.1016/j.intermet.2011.02.018

Several samples were prepared in the title systems, starting from the elements sealed under argon in Ta crucibles, melting in an induction fornace and annealing at 823 K. Six ternary phases were found: EuCu 2Sn 2, a = 11.100 (3), b = 4.307 (1), c = 4.824 (1) Å, β = 108.88 (1)°, and SrCu 2Sn 2, a = 11.197 (4), b = 4.322 (2), c = 4.859 (1) Å, β = 108.43 (1)°, C2/ m, CaCu 2Sn 2-type, closely related to the BaAl 4 structure; Sr 3Cu 8Sn 4, a = 9.3280 (2), c = 7.8826 (4) Å, P6 3 mc, Nd 3Co 8Sn 4-type, ordered variant of the BaLi 4-type; SrCu 4Sn 2, a = 8.176 (1), c = 7.799 (1) Å, I4/ mcm, CaNi 4Sn 2-type; SrCu 9Sn 4, a = 8.663 (1), c = 12.457 (2) Å, and BaCu 9Sn 4, a = 8.717 (1), c = 12.545 (2) Å, I4/ mcm, LaFe 9Si 4-type, ordered variant of the NaZn 13 structure. The structure of the first compound was refined by the Rietveld method, while single crystal data were used for the others. Some remarks are given on the crystal chemistry of the encountered and related structure types. The following new compounds have been synthesized and characterized by X-Ray diffraction: EuCu 2Sn 2, SrCu 2Sn 2, Sr 3Cu 8Sn 4, SrCu 4Sn 2, SrCu 9Sn 4 and BaCu 9Sn 4. The crystal chemistry of the encountered and related structure types is discussed. [Display omitted] ► The new phases SrCu 2Sn 2, Sr 3Cu 8Sn 4, SrCu 4Sn 2, SrCu 9Sn 4 and BaCu 9Sn 4 identified. ► The structure of the above phases refined by single crystal X-ray analysis ► The new phase EuCu 2Sn 2 identified and structurally refined by Rietveld method ► Crystal chemical remarks on the CaCu 2Sn 2, Nd 3Cu 8Sn 4, CaNi 4Sn 2 and LaFe 9Si 4-types.