標題: Synthesis and Characterization of Ba[CoSO]: Magnetic Complexity in the Presence of Chalcogen Ordering
作者: Valldor, Martin
Roessler, Ulrich K.
Prots, Yurii
Kuo, Chang-Yang
Chiang, Jen-Che
Hu, Zhiwei
Pi, Tun-Wen
Kniep, Ruediger
Tjeng, Liu Hao
物理研究所
Institute of Physics
關鍵字: anions;chalcogens;cobalt;density functional calculations;magnetic properties;X-ray absorption spectroscopy
公開日期: 20-Jul-2015
摘要: Barium thio-oxocobaltate(II), Ba[CoS2/2O2/2], was synthesized by the reaction of equimolar amounts of BaO, Co, and S in closed silica ampoules. The title compound (Cmcm, a=3.98808(3), b=12.75518(9), c=6.10697(4)angstrom) is isostructural to Ba[ZnSO]. The use of soft X-ray absorption spectroscopy confirmed that cobalt is in the oxidation state +2 and tetrahedrally coordinated. Its coordination consists of two sulfur and two oxygen atoms in an ordered fashion. High-temperature magnetic susceptibility data indicate strong low-dimensional spin-spin interactions, which are suggested to be closely related to the layer-type crystal structure and perhaps the ordered distribution of sulfur and oxygen. Antiferromagnetic ordering below T-N=222K is observed as an anomaly in the specific heat, coinciding with a significant lowering of the magnetic susceptibility. Density functional theory calculations within a generalized-gradient approximation (GGA)+U approach identify an antiferromagnetic ground state within the square-like two-dimensional layers of Co, and antiferromagnetic correlations for nearest and next nearest neighbors along bonds mediated by oxygen or sulfur. However, this magnetic state is subject to frustration by relatively strong interlayer couplings.
URI: http://dx.doi.org/10.1002/chem.201501024
http://hdl.handle.net/11536/128034
ISSN: 0947-6539
DOI: 10.1002/chem.201501024
期刊: CHEMISTRY-A EUROPEAN JOURNAL
Volume: 21
Issue: 30
起始頁: 10821
結束頁: 10828
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