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Baba, Yuji; Shimoyama, Iwao; Hirao, Norie
no journal, ,
In order to clarify chemical states of radioactive cesium in clay and soil, X-ray photoelectron spectra (XPS) have been measured for cesium sorbed in laminar oxides such as mica. Since the number of atoms in radionuclides such as 
Cs is extremely small, we have measured XPS spectra under total reflection condition of incident X-rays. This method enabled us to measure XPS spectra for ultra-trace level alkali metals down to 1/1000 monolayer. For rubidium and cesium, the XPS core levels shifted to lower energy side with the decrease in the number of layer. While for sodium, the direction of the energy shift was reverse to those of rubidium and cesium. On the basis of point charge model, it was clarified that the lower the number of layer is, the stronger the iconicity of the chemical bond becomes for rubidium and cesium.
Koike, Masato; Nagano, Tetsuya*
no journal, ,
Recently in the manufacture of high-strength steel used in the construction material such as a frame for a motor vehicle for weight reduction is progressing (high-tension) is carbon, silicon, manganese, titanium, etc., it will manage the allocation of 10 several kinds of elements in the ppm level that there is a need. Furthermore it is required to clarify the interactions with other elements (Fe, C, Ni, Mn, Cr, etc.) and the origins of various physical properties. The authors found a new way to dramatically increase the diffraction efficiency of the laminar type diffraction grating using a metal single-layer film such as a conventional gold in B-K emission (6.76 nm) around the wavelength range. This phenomenon occurs by putting a transparent layer having a certain thickness on the metal surface of the laminar-type diffraction grating in the grazing incidence condition which causes total reflection. For the transparent layer, it is desirable to have an intermediate refractive index of a vacuum and the metal layer. TiO
, CeO or the like, a promising candidate to meet this criterion were found to be one of the participants. The results of numerical calculation, the diffraction efficiency at 6.76 nm, TiO, the case of both of CeO is 22% both diffraction efficiency of at 6.76nm, expected a significant improvement from the 14.1% of 15.6% and Au of Ni differentially.
Okamoto, Yoshihiro; Shiwaku, Hideaki
no journal, ,
The chemical correlation between two elements in the material was tried to analyze using extension of the imaging XAFS technique. Since the imaging XAFS spectrum contains information on position in the material, XAFS data corresponding to the specific domain in the material can be selectively obtained in the analysis. In the presentation, this new imaging XAFS analytical technique is introduced together with some examples.
Sasaki, Takuo; Takahashi, Masamitsu
no journal, ,
no abstracts in English
Sekiguchi, Tetsuhiro; Honda, Mitsunori; Hirao, Norie; Ikeura, Hiromi*
no journal, ,
High degrees of molecular orientation play a crucial role in the improvement of electronic properties in organic semiconductors. Thus, it is essential to selectively characterize materials with different orientation direction in microscopic domains. So far, we have strived to observe orientation of organic-semiconductors in microscopic domains using the photoelectron emission microscopy (PEEM) system with excitation by linearly polarized ultraviolet (UV) light from mercury lamp and synchrotron X-rays.
Kimata, Tetsuya*; Yamaki, Tetsuya; Yamamoto, Shunya; Hakoda, Teruyuki; Matsumura, Daiju; Shimoyama, Iwao; Iwase, Akihiro*; Fujimura, Yuki*; Kobayashi, Tomohiro*; Terai, Takayuki*
no journal, ,
Carbon-supported platinum (Pt) nanoparticles have been studied intensively for applications to oxygen reduction reaction (ORR) catalysts in polymer electrolyte fuel cells. The Pt nanoparticles on the Ar-ion-irradiated glassy carbon (GC) substrate were previously found to improve ORR activity. We analyzed here the local structure by XAFS measurements to clarify the mechanism of the Pt-C bonding at the Pt/GC interface, which could contribute to the observed high ORR activity. A decrease in the white-line intensity at Pt M
and L edges suggests the reduction of the vacancy in the Pt 5d orbital, thereby leading to the interfacial structure with suppressed oxygen adsorbability.