Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature

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	Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature; Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature
	S. Y. Wu; G. D. Lu; H. M. Zhang; Z. H. Zhang
	2007 ; 2007
发表期刊	Physica C-Superconductivity and Its Applications ; Physica C-Superconductivity and Its Applications
ISSN	0921-4534 ; 0921-4534
卷号	466 期号:1-2 页码:163-167
摘要	The anisotropic g factors g(x), g(y) and g(z) for the orthorhombic Co2+ center on the Cu(l) site in YBa2Cu2.7CO0.3O7-x at room temperature are theoretically investigated from the perturbation formulae of the g factors for a 3d(7) ion having low spin (S = 1/2) under octahedra with orthorhombic distortion. In these formulae, the contributions to the g factors from the orthorhombic crystal-fields as well as the ligand orbitals and spin-orbit coupling are taken into account based on the cluster approach. This center may be attributed to Co2+ located in a moderately compressed oxygen octahedron with additional orthorhombic distortion. The significant decline (characterized by the reduction factor y approximate to 0.13) of the energy separations due to the Jahn-Teller effect is suggested, by analyzing the experimental g factors. The calculated g factors based on the above contributions show good agreement with the observed values. In addition, the pronounced decrease in the intensity and the remarkable nonlinear increase in the g, of Co2+ EPR spectra as the temperature is lowered from room temperature to 150 K are also mentioned, in view of the opening of the spin gap due to antiferromagnetic interactions. (c) 2007 Elsevier B.V. All rights reserved.; The anisotropic g factors g(x), g(y) and g(z) for the orthorhombic Co2+ center on the Cu(l) site in YBa2Cu2.7CO0.3O7-x at room temperature are theoretically investigated from the perturbation formulae of the g factors for a 3d(7) ion having low spin (S = 1/2) under octahedra with orthorhombic distortion. In these formulae, the contributions to the g factors from the orthorhombic crystal-fields as well as the ligand orbitals and spin-orbit coupling are taken into account based on the cluster approach. This center may be attributed to Co2+ located in a moderately compressed oxygen octahedron with additional orthorhombic distortion. The significant decline (characterized by the reduction factor y approximate to 0.13) of the energy separations due to the Jahn-Teller effect is suggested, by analyzing the experimental g factors. The calculated g factors based on the above contributions show good agreement with the observed values. In addition, the pronounced decrease in the intensity and the remarkable nonlinear increase in the g, of Co2+ EPR spectra as the temperature is lowered from room temperature to 150 K are also mentioned, in view of the opening of the spin gap due to antiferromagnetic interactions. (c) 2007 Elsevier B.V. All rights reserved.
部门归属	univ elect sci & technol china, dept appl phys, chengdu 610054, peoples r china. chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china.;wu, sy (reprint author), univ elect sci & technol china, dept appl phys, chengdu 610054, peoples r china;wushaoyi@netease.com ; univ elect sci & technol china, dept appl phys, chengdu 610054, peoples r china. chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china.;wu, sy (reprint author), univ elect sci & technol china, dept appl phys, chengdu 610054, peoples r china;wushaoyi@netease.com
关键词	Electron Paramagnetic Resonance Electron Paramagnetic Resonance Crystal Fields And Spin Hamiltonians Crystal Fields And Spin Hamiltonians Co2++ Co2++ Yba2cu2.7co0.3o7-x Yba2cu2.7co0.3o7-x Atomic Screening Constants Atomic Screening Constants D-orbital Theory D-orbital Theory Paramagnetic-resonance Paramagnetic-resonance Scf Functions Scf Functions Spin Gap Spin Gap Field Field Ions Ions 0-less-than-or-equal-to-x-less-than-or-equal-to-0.30 0-less-than-or-equal-to-x-less-than-or-equal-to-0.30 Yba2cu3o7-delta Yba2cu3o7-delta La2-xsrxcuo4 La2-xsrxcuo4
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WOS记录号	WOS:000250695900026 ; WOS:000250695900026
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/321006/33916
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	S. Y. Wu,G. D. Lu,H. M. Zhang,et al. Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature, Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature[J]. Physica C-Superconductivity and Its Applications, Physica C-Superconductivity and Its Applications,2007, 2007,466, 466(1-2):163-167, 163-167.
APA	S. Y. Wu,G. D. Lu,H. M. Zhang,&Z. H. Zhang.(2007).Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature.Physica C-Superconductivity and Its Applications,466(1-2),163-167.
MLA	S. Y. Wu,et al."Investigations of the g factors for the orthorhombic Co2+ center in YBa2Cu2.7Co0.3O7-x at room temperature".Physica C-Superconductivity and Its Applications 466.1-2(2007):163-167.