Theoretical investigations of the local structure and the EPR parameters for the trigonal Co2+ center in K4CdCl6

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	Theoretical investigations of the local structure and the EPR parameters for the trigonal Co2+ center in K4CdCl6
	S. Y. Wu; H. N. Dong; W. H. Wei
	2004
发表期刊	Journal of Magnetism and Magnetic Materials
ISSN	0304-8853
卷号	279 期号:1 页码:14-20
摘要	The local structure and the electron paramagnetic resonance (EPR) g factors g(parallel to), g(perpendicular to) and the hyperfine structure constants A(parallel to) and A (perpendicular to) for the trigonal Co2+ center in K4CdCl6 are theoretically investigated by using the perturbation formulas of the EPR parameters for a 3d 7 ion in trigonal symmetry based on the cluster approach. In these formulas, the contributions to the EPR parameters arising from the admixture of different energy levels, covalency effect and low symmetry distortion are included. The parameters related to the above effects are obtained from the optical spectral data and the local geometrical relationship of the studied system. By analyzing the EPR spectra, we find that the impurity-ligand bonding angle beta (approximate to53.54degrees) related to the C-3-axis in the Co2+ impurity center is smaller than the corresponding metal-ligand bonding angle beta(H) (approximate to 54.90degrees) in the host K4CdCl6. From the difference Deltabeta between the bonding angle beta (or beta(H)) and the corresponding angle beta(0) (approximate to54.74degrees) in cubic symmetry, the chlorine octahedron changes from compression (Deltabeta(H) = beta(H) - beta(0) > 0) in the host to elongation (Deltabeta = beta - beta(0) < 0) in the impurity center. The calculated EPR parameters, especially the anisotropies of the g and A factors for K4CdCl6: Co2+ based on the angle beta show good agreement with the observed data. The theoretical studies on the local structure for Co2+ in K4CdCl6 would be helpful to understand the structure properties for the equivalent octahedral transition-metal M site in the isostructural A(3)M'MO6 compounds. (C) 2003 Elsevier B.V. All rights reserved.
部门归属	univ elect sci & technol china, coll phys elect, dept appl phys, chengdu 610054, peoples r china. chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china. chongqing inst posts & telecommun, coll elect engn, chongqing 400065, peoples r china.;wu, sy (reprint author), univ elect sci & technol china, coll phys elect, dept appl phys, chengdu 610054, peoples r china;wushaoyi@netease.com
关键词	Defect Structure Electron Paramagnetic Resonance Crystal- And Ligand-field Co2++ K4cdcl6 Atomic Screening Constants Magnetic-properties Superposition Model Rh(Iii) Compounds Scf Functions Sr3mrho6 m Cr3++ Ions Crystals Impurities Transition
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WOS记录号	WOS:000222954600003
引用统计	被引频次：2[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/35628
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	S. Y. Wu,H. N. Dong,W. H. Wei. Theoretical investigations of the local structure and the EPR parameters for the trigonal Co2+ center in K4CdCl6[J]. Journal of Magnetism and Magnetic Materials,2004,279(1):14-20.
APA	S. Y. Wu,H. N. Dong,&W. H. Wei.(2004).Theoretical investigations of the local structure and the EPR parameters for the trigonal Co2+ center in K4CdCl6.Journal of Magnetism and Magnetic Materials,279(1),14-20.
MLA	S. Y. Wu,et al."Theoretical investigations of the local structure and the EPR parameters for the trigonal Co2+ center in K4CdCl6".Journal of Magnetism and Magnetic Materials 279.1(2004):14-20.