Study of distribution of spin-polarization in alloys of rare-earth and transitional elements

稀土及过渡元素合金中自旋极化分布的研究

• 批准号: 11450236
• 负责人: NANAO Susumu
• 金额: $ 4.22万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450236/
• 关键词: rare-earth; transition metals; magnetism; magnetic EXAFS; distribution of spin polarization; muti-electron excitation; magnetic circular dichroism; synchrotron radiation; EXAFS; DyFe2; Nd-Fe-B; X線発光分光; Nd-FeーB

The present study has been executed for the period from 1999 to 2000. The objectives are to establish the methods for the high precision measurement and the analysis of magnetic EXAFS and to clarify the distribution of spin-polarization in the alloys of rare-earth and transitional elements, taking full advantages magnetic EXAFS.The main results are as follows ;(1) Magnetic EXAFS spectra for NdCo2 and TbFe2 were measured and the magnetic structures were analyzed.The advantages and problems of magnetic EXAFS were pointed out. Then the novel method for the analysis of magnetic EXAFS has developed. It has shown that the method enables us to obtain pair-distribution functions including the information on the direction of the spin magnetic moment of the constituent atoms. This is one of the quite useful functions of magnetic EXAFS for the analysis of magnetic structures.It was also pointed out that the following two terms are the most significant problems to overcome at present stage. (a) The some parameters in the analysis, such as phase factors, backgrounds, are not so reliable.(b) The effect of the magnetic multi-electron excitation (MMEE) is so large that erroneous magnetic structures will result in if the spectra are analyzed including MMEE.(2) In order to improve the reliability of the analysis for a magnetic EXAFS spectrum, the details of MMEE were studied. The information on the intensity and the excitation energy of an MMEE spectrum was obtained in detail and the influence on the analysis of a magnetic EXAFS spectrum was estimated.(3) The x-ray emission spectra and x-ray magnetic absorption spectra were measured for rare-earth and transition metal elements, and the information is accumulated on the mechanism of magnetic circular dichroism in these elements

本研究是在1999年至2000年期间进行的。目的是建立高精度的磁EXAFS测量和分析方法，充分利用磁EXAFS的优势，弄清稀土和过渡族合金中自旋极化的分布。（一）测量了NdCo2和TbFe2的磁EXAFS谱，分析了磁结构，指出了磁EXAFS的优点和存在的问题指出了在此基础上，提出了一种新的磁EXAFS分析方法。结果表明，该方法使我们能够获得包含组成原子自旋磁矩方向信息的对分布函数。这是磁EXAFS对磁结构分析的一个十分有用的功能，并指出以下两项是现阶段最需要克服的问题。(a)分析中的一些参数，如相位因子、背景等，并不十分可靠。(b)磁多电子激发效应非常大，如果分析包含磁多电子激发的谱，将导致错误的磁结构。(2)为了提高磁EXAFS谱分析的可靠性，对磁谱的细节进行了研究。详细地获得了磁谱的强度和激发能信息，并估计了对磁EXAFS谱分析的影响。(3)测量了稀土和过渡金属元素的x射线发射谱和x射线磁吸收谱，积累了有关稀土和过渡金属元素磁圆二色性机理的信息

项目成果

T.Nakamura et al.: "Magnetic Circular Dichroism of Resonant Inelastic X-ray Scattering of 3d5/2-2p3/2 at the Ho LIII-edge in Ho3Fe5O12"J.Synchrotron Rad.. 8. 428-430 (2001)

T.Nakamura 等人：“Ho3Fe5O12 中 Ho LIII 边缘处 3d5/2-2p3/2 共振非弹性 X 射线散射的磁圆二色性”J.Synchrotron Rad.. 8. 428-430 (2001)

T.Nakamura: "Magnetic Circular Dichroism of Resonant Inelastic X-ray Scattering of 3d5/2-2p3/2 at the Ho LIII-edge in Ho3Fe5012"J.Synchrotron Rad.. 8. 428-430 (2001)

T.Nakamura：“Ho3Fe5012 中 Ho LIII 边缘处 3d5/2-2p3/2 共振非弹性 X 射线散射的磁圆二色性”J.Synchrotron Rad.. 8. 428-430 (2001)

T.Nakamura: "Magnetic Circular Dichroism of Resonant Inelastic X-ray Scattering of 3d5/2-2p3/2 at the Ho LIII-edge in Ho3Fe5O12"J.Synchrotron Rad.. 8. 428-430 (2001)

T.Nakamura：“Ho3Fe5O12 中 Ho LIII 边缘处 3d5/2-2p3/2 共振非弹性 X 射线散射的磁圆二色性”J.Synchrotron Rad.. 8. 428-430 (2001)

七尾進: "磁気EXAFS"日本放射光学会誌. 13. 33-39 (2000)

Susumu Nanao：“Magnetic EXAFS”日本辐射光学学会杂志 13. 33-39 (2000)。

Y.Watanabe et al.: "X-ray magnetic circular dichroism in quasicrystals"Mater.Sci.Eng.. A294-296. 617-620 (2000)

Y.Watanabe 等人：“准晶体中的 X 射线磁圆二色性”Mater.Sci.Eng.. A294-296。