Crystal and Magnetic Structures of the Oxide Sulfides CaCoSO and BaCoSO.
Crystal and Magnetic Structures of the Oxide Sulfides CaCoSO and BaCoSO.
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DOI：
10.1021/acs.inorgchem.5b02615
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发表时间：
2016-01
影响因子：
4.6
通讯作者：
Edward J. T. Salter;J. Blandy;S. Clarke
中科院分区：
文献类型：
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作者：
Edward J. T. Salter;J. Blandy;S. Clarke
CaCoSO是由CaO、Co和S在900℃合成的CaCoSO，与CaZnSO和CaFeSO是等结构的。这种结构是非中心对称的，这是由于共享顶点的CoS3O四面体的排列，这些四面体通过硫化物的顶点连接在一起形成层。晶体结构采用P63mc空间群(第186号)，室温下晶格参数为a=3.7524(9)ä和c=11.138(3)ä，晶胞中有两个公式单元。该化合物具有很高的绝缘性，粉末中子衍射测量表明，该化合物具有长程反铁磁序，传播矢量k=(1/3，1/3，1/2)。粉末样品的磁散射可以从Co(2+)自旋矢量在三角形平面上的12 0°排列开始，然后在平面外倾斜，可以在磁空间群C(C)c(Belov，Neronova和Smirnova(BNS)方案中的9.40空间群)中建模，Co(2+)矩为2.72(5)μ(B)。还描述了最近报道的具有与CaCoSO完全不同的晶体结构的化合物BaCoSO的反铁磁结构，实验发现这种磁结构和有序矩(2.75(2)μ(B))的大小与计算结果相似。
CaCoSO, synthesized from CaO, Co, and S at 900 °C, is isostructural with CaZnSO and CaFeSO. The structure is non-centrosymmetric by virtue of the arrangement of the vertex-sharing CoS3O tetrahedra which are linked by their sulfide vertices to form layers. The crystal structure adopts space group P63mc (No. 186), and the lattice parameters are a = 3.7524(9) Å and c = 11.138(3) Å at room temperature with two formula units in the unit cell. The compound is highly insulating, and powder neutron diffraction measurements reveal long-range antiferromagnetic order with a propagation vector k = (1/3, 1/3, 1/2). The magnetic scattering from a powder sample can be modeled starting from a 120° arrangement of Co(2+) spin vectors in the triangular planes and then applying a canting out of the planes which can be modeled in the magnetic space group C(c)c (space group 9.40 in the Belov, Neronova, and Smirnova (BNS) scheme) with Co(2+) moments of 2.72(5) μ(B). The antiferromagnetic structure of the recently reported compound BaCoSO, which has a very different crystal structure from CaCoSO, is also described, and this magnetic structure and the magnitude of the ordered moment (2.75(2) μ(B)) are found by experiment to be similar to those predicted computationally.