In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 62, No. 1 ( 2007-1-1), p. 5-14
Abstract:
Eu 5 Sn 3 S 12 and Eu 4 LuSn 3 S 12 were synthesized and their structures refined from single crystal data (Pmc2 1 , Eu 5 Sn 3 S 12 : a = 3.908(1), b = 20.115(4), c = 11.451(2) Å ; wR2 = 0.0519 for 3048 F 2 and 122 parameters; Eu 4 LuSn 3 S 12 : a = 3.920(1), b = 20.132(4), c = 11.459(2) Å ; wR2 = 0.0737 for 3298 F 2 and 122 parameters). The structures contain one-dimensional chains of edge-sharing SnS 2 S 4/2 octahedra and corner-sharing SnS3S2/2 trigonal bipyramids, running parallel to [100]. Five europium sites are seven- or eightfold coordinated by sulfur atoms. Lutetium atoms in Eu 4 LuSn 3 S 12 show a strong site preference for one of the two Eu 3+ positions of Eu 5 Sn 3 S 12 and no structural disorder was observed. Both compounds show static mixed valence according to Eu 2+ 3 Eu 3+ 2 Sn 4+ 3 S 2− 12 and Eu 2+ 3 Eu 3+ Lu 3+ Sn 4+ 3 S 2− 12 , which was confirmed by temperature dependent magnetic susceptibility measurements. The experimental magnetic moments of 14.6(1) (Eu 5 Sn 3 S 12 ) and 14.1(1) (Eu 4 LuSn 3 S 12 ) μ B /f.u. indicate that each of the two sulfides contains three divalent europium atoms per formula unit. Magnetic ordering for Eu 5 Sn 3 S 12 and Eu 4 LuSn 3 S 12 sets in below 5 and 3 K, respectively. Both sulfides show metamagnetic or spin-flip transitions in the magnetization curves at 3 K (2 K) with full saturation of the europium magnetic moments at 3 K (2 K) and 80 kOe. 151 Eu Mössbauer spectra fully confirm the Eu 2+ and Eu 3+ site occupancies. At 4.2 K an increase in line width indicates small hyperfine fields at the europium nuclei.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-2007-0102
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2007
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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