Investigations of the local structures and the EPR g factors for V(4+) and Cr(4+) in Bi(4)Ge(3)O(12) crystals

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	Investigations of the local structures and the EPR g factors for V(4+) and Cr(4+) in Bi(4)Ge(3)O(12) crystals
	Z. H. Zhang; S. Y. Wu; L. L. Li
	2010
发表期刊	Journal of Molecular Structure-Theochem
ISSN	0166-1280
卷号	959 期号:1-3 页码:113-116
摘要	The local structures and the electron paramagnetic resonance (EPR) g factors g(parallel to) and g(perpendicular to) for the substitutional V(4+) and Cr(4+) at the Ge(4+) sites in Bi(4)Ge(3)O(12) are theoretically investigated from the perturbation formulas of the g factors for 3d(1) and 3d(2) ions under tetragonally elongated tetrahedra. In the calculations, the ligand orbital and spin-orbit coupling contributions are taken into account from the cluster approach in view of the covalency of the systems. The local impurity-ligand bond angles beta related to the C(4) axis in the V(4+) and Cr(4+) centers are found to be about 5 degrees and 6 degrees, respectively, lower than the host angle beta(H) in the pure crystal. So the ligand tetrahedra transform from original compression at the host Ge(4+) site into elongation in the impurity centers due to the size mismatching substitution of the smaller Ge(4+) by the larger impurities. Meanwhile, the Jahn-Teller effect also brings forward some contribution to the local structure of the V(4+) center. The calculated g factors are in good agreement with the experimental data. The local structures of both centers are discussed. (C) 2010 Elsevier B.V. All rights reserved.
部门归属	[zhang, zhi-hong; wu, shao-yi; li, li-li] univ elect sci & technol china, dept appl phys, chengdu 610054, peoples r china. [wu, shao-yi] chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china.;zhang, zh (reprint author), univ elect sci & technol china, dept appl phys, chengdu 610054, peoples r china;zhihongzhang723@163.com
关键词	Electron Paramagnetic Resonance v(4+) Cr(4+) Bi(4)Ge(3)o(12) Atomic Screening Constants Superposition Model Sillenite Crystals Single-crystals Scf Functions Ions Parameters Spectrum Impurity Vanadium
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/31736
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. H. Zhang,S. Y. Wu,L. L. Li. Investigations of the local structures and the EPR g factors for V(4+) and Cr(4+) in Bi(4)Ge(3)O(12) crystals[J]. Journal of Molecular Structure-Theochem,2010,959(1-3):113-116.
APA	Z. H. Zhang,S. Y. Wu,&L. L. Li.(2010).Investigations of the local structures and the EPR g factors for V(4+) and Cr(4+) in Bi(4)Ge(3)O(12) crystals.Journal of Molecular Structure-Theochem,959(1-3),113-116.
MLA	Z. H. Zhang,et al."Investigations of the local structures and the EPR g factors for V(4+) and Cr(4+) in Bi(4)Ge(3)O(12) crystals".Journal of Molecular Structure-Theochem 959.1-3(2010):113-116.