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

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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