Crystal and Magnetic Structures of the Oxide Sulfides CaCoSO and BaCoSO

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• 作者：Edward J. T. Salter ; Jack N. Blandy ; Simon J. Clarke
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：February 15, 2016
• 年：2016
• 卷：55
• 期：4
• 页码：1697-1701
• 全文大小：348K
• ISSN：1520-510X

文摘

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 Co²⁺ 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_cc (space group 9.40 in the Belov, Neronova, and Smirnova (BNS) scheme) with Co²⁺ 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.