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Synthesis and Characterization of Ba[CoSO]: Magnetic Complexity in the Presence of Chalcogen Ordering
Author(s) -
Valldor Martin,
Rößler Ulrich K.,
Prots Yurii,
Kuo ChangYang,
Chiang JenChe,
Hu Zhiwei,
Pi TunWen,
Kniep Rüdiger,
Tjeng Liu Hao
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201501024
Subject(s) - antiferromagnetism , isostructural , chalcogen , magnetic susceptibility , crystallography , chemistry , oxidation state , density functional theory , condensed matter physics , ground state , crystal structure , materials science , computational chemistry , physics , metal , atomic physics , organic chemistry
Barium thio‐oxocobaltate(II), Ba[CoS 2/2 O 2/2 ], 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) Å) 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 =222 K 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.