2006 Fiscal Year Final Research Report Summary
Spin-selective XAFS: a noble analytical method for magnetic nano-particles
| Project/Area Number |
17510094
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nanomaterials/Nanobioscience
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| Research Institution | Japan Women's University (2006)
Tohoku University (2005) |
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Principal Investigator |
HAYASHI Hisashi Japan Women's Univ., Fac. of Sci., Asso. Prof., 理学部, 助教授 (60250833)
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| Co-Investigator(Kenkyū-buntansha) |
BALACHANDRAN Jeyadevan Tohoku Univ., Graduate School of Environmental Studies, Prof., 大学院環境科学研究科, 教授 (80261593)
SHINODA Kozo Tohoku Univ., IMRAM, Lecturer, 多元物質科学研究所, 講師 (10311549)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Spin-selective XAFS / Resonant inelastic x-ray scattering / X-ray spectrometer with high-sensitivity / X-ray satellites / Magnetic nano-particles |
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| Research Abstract |
This project aims to establish spin-selective XAFS spectroscopy as a method of characterizing the magnetic and electronic structure of magnetic nano-particles. Here it is necessary to develop high-resolution x-ray spectrometers with large acceptance in order to measure generally weak Kβ-emissions of 3d elements.
In 2005, our own dispersive-type spectrometer was modified for detecting Kβ-emissions, and was utilized for observing resonant inelastic x-ray scattering (RIXS) of several standard materials to deduce their spin-selective XAFS. Through these measurements, it has been achieved to ultimately suppress lifetime-broadenings, and to obtain polarized spin-selective XAFS for single-crystal of LaMnO_3. On the other hand, it has been found that magnetic nano-particles are unstable for incident x-rays produced by synchrotron sources. The instability made it difficult to precisely obtain the spin-selective XAFS of the particles.
Thus, in 2006, a focusing-type spectrometer was made by rebuilding the dispersive-type spectrometer, and was named as 'Peacock' after its shape. By using the 'Peacock', lifetime-broadening-suppressed XAFS spectra of CuO nano-particles on ZnO with various Cu concentrations up to as low as 1 mol% were obtained from their RIXS. Similar experiments for a basic high-Tc system, La_<2-x>Sr_xCuO_4 (LSCO) reveal that 1s-3d excitation of LSCO is very sensitive Sr-concentration and polarization. After these preliminary studies to demonstrate the high-sensitivity of 'Peacock', spin-selective XAFS spectra of magnetic nano-materials of several Fe oxides were measured within fairly short periods. Here almost no radiation-damage was distinguishable. Based on the data obtained, papers are now in preparation.
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Research Products
(12 results)
