Volume 10, No.1
January issue 2005
1. SPring-8の現状／PRESENT STATUS OF SPring-8
2. 最近の研究から／FROM LATEST RESEARCH
Direct Observation of Ferromagnetic Spin Polarization in Au Nanoparticles by Element Specific Magnetization Measurement
北陸先端科学技術大学院大学 材料科学研究科 School of Materials Science, Japan Advanced Institute of Science and Technology
- Gold shows diamagnetic property in the bulk state. However, this property might be different in the nano-sized region because the electronic structure may be modified significantly. This article reports the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms estimated by XMCD shows a good agreement with the results obtained by conventional magnetometry. This result is evidence of intrinsic spin polarization in nano-sized gold.
Direct observation of hydrogen molecules adsorbed in a microporous coordination polymer
大阪女子大学 理学部 Department of Environmental Sciences, Osaka Women’s University、（財）高輝度光科学研究センター 利用研究促進部門Ⅰ／CREST (JST) Materials Science Division, JASRI / CREST、京都大学大学院 工学研究科 Department of Synthetic Chemistry and Biological Chemistry, Kyoto University、（財）高輝度光科学研究センター 利用研究促進部門Ⅰ／CREST (JST)、Materials Science Division, JASRI / CREST、岡山大学 理学部 Department of Physics, Okayama University、名古屋大学大学院 工学研究科 Department of Applied Physics, Nagoya University
- Hydrogen storage is one of the most important technologies, which is indispensable for the establishment of clean hydrogen energy system. Adsorption of H2 molecules in the metal-organic porous materials is one of the most promising candidates to store and release H2 molecules efficiently. To develop a rational synthetic strategy for novel metal-organic porous materials as hydrogen storages, the elucidation of the intermolecular interaction between H2 molecules and pore walls is essential and the fundamental structural characteristics of H2 molecules are required. Although the weakest X-ray scattering amplitude of hydrogen made it difficult to determine the structure, we have succeeded in direct observation of H2 molecules adsorbed in the nano-channels of the metal-organic porous material by in-situ synchrotron powder diffraction experiment of gas adsorption and MEM(maximum entropy method)/Rietveld analysis. The result could give us promising guidelines for designing hydrogen gas storage materials.