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Agui, Akane; Kmbre, T.*; Sthe, C.*; Nordgren, J.*; Usuda, Manabu; Saito, Tomohiko*; Moritomo, Yutaka*
Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.589 - 592, 2005/06
Times Cited Count:1 Percentile:5.68(Spectroscopy)Current research in the perovskite and layered perovskite-type manganese oxides has expanded to include the study of electronic and magnetic properties such as the colossal magnetoresistance (CMR), orbital ordering and charge ordering. The O K soft X-ray emission and absorption spectra (XES and XAS) of LaSrMnO were measured at selected excitation energies in order to investigate the electronic structure. The measurements were carried out by using a soft X-ray emission spectrometer at beamline BW3 at HASYLAB, Germany. The dependence of O K XES on excitation-energy was observed. It is attributed the different site of oxygen ions.
Yokoya, Akinari; Takakura, Kaoru*; Watanabe, Ritsuko; Akamatsu, Ken*; Ito, Takashi*
Radiation Research, 162(4), p.469 - 473, 2004/10
Radicals induced in a single crystal of 5-bromouracil (BrUra) by synchrotron soft X-rays in the Br K-edge region (13.461-13482 keV) were investigated using the X-band EPR method. The crystal was irradiated at three peak energies in the absorption spectrum at room temperature or at 80K. A hydrogen abstraction radical derived from N1 atom of the pyrimidine ring was commonly observed for all of the energies used, though with some variation in quantity. Similar characteristics were also observed in the EPR signal for the off-K-edge low energy (13.42 keV) and when Co -ray irradiation was employed as the reference. When irradiated at 80K, a much larger exposure (roughly 10 times) of soft X-rays was needed to obtain the same signal intensity as that observed at room temperature. EPR signals were not detectable with g-irradiation at liquid nitrogen temperature.
Tanaka, Masahito*; Nakagawa, Kazumichi*; Koketsu, Toshiyuki*; Agui, Akane; Yokoya, Akinari
Journal of Synchrotron Radiation, 8(Part2), p.1009 - 1011, 2001/03
Amino acid molecules are known to be in the state of so-called "zwitter-ion" in solid phase and its extremely low vapour pressure makes ultra high vacuum experiment such as the XANES experiment possible. Recently, C-K edge XANES spectra of aromatic amino acids were studied experimentally and theoretically. Here we selected oxygen K-edge for XANES study of amino acids. From the view point of K-edge XANES study in amino acids, oxygen is interesting because its chemical states have the wealth of variety. A carboxylic group on the carbon is in the state of carboxylic anion -COO-, while carboxylic group in side-chain stays on -COOH, and some amino acids have -OH group in side-chain. Due to this variety of chemical environment, we can expect characteristic chemical shift for each oxygen atom in various amino acids. In this paper, we report a result of oxygen K-edge XANES spectra of amino acids (glycine, L-a-alanine, b-alanine, L-serine, L-asparic acid and L-tyrosine) films. We discuss the details of spectra on the basis of DV-X calculation.
Baba, Yuji; Sekiguchi, Tetsuhiro
Photon Factory Activity Report 1998, P. 34, 1999/11
no abstracts in English
Kasatani, Hirofumi*; Omura, Masashi*; Yokoyama, Katsumi*; Kobayashi, Kurima*; Nishihata, Yasuo; Yagi, Kenichiro*; Terauchi, Hikaru*
Japanese Journal of Applied Physics, 38(Suppl.38-1), p.433 - 435, 1999/06
Times Cited Count:3 Percentile:18.86(Physics, Applied)High energy XAFS studies of Sm: K-edge in Sm2Fe17Nx with x = 0.0, <= 0.1, 0.5, 2.0 and 3.0 were carried out at room temperature in order to clarify the relation between the local structure around the Sm-atom and the change of the magnetic property due to the absorption of nitrogen atom. In the XANES region, we firstly found the change of Sm electron state by nitriding because of the change of the shape in the absorption edge junp. In the result of the EXAFS spectra, we confirmed that the Sm-Fe distance was expanded monotonously due to the absorption of N-atom.
Sonoda, Takashi; Togashi, Yoshihiro; Miyauchi, Masakatsu; Okazaki, Shuji*
JAERI-Tech 99-043, 16 Pages, 1999/05
no abstracts in English
Kubozono, Yoshihiro*; Mimura, Kazue*; Takabayashi, Yasuhiro*; Maeda, Hironobu*; Kashino, Setsuo*; Emura, Shuichi*; Nishihata, Yasuo; Uruga, Tomoya*; Tanaka, Tsunehiro*; Takahashi, Masao*
Journal of Synchrotron Radiation, 6(Part3), p.564 - 566, 1999/05
The Rb K-edge XAFS spectra for the stable phase of RbC60 which is a quasi one-dimensional polymer were measured in the temperature range from 14.6 to 210 K in order to clarify the origin of the metal-insulator transition around 50 K. The distances and mean-square relative displacements between the Rb atom and the neighboring C atoms determined by XAFS exhibited no change around 50 K, implying that the metal-insulator transition originates from the SDW instablity.
*; *; *
Inst. Phys. Conf. Ser., (159), p.455 - 458, 1999/00
no abstracts in English
Chihara, Junzo
Journal of Physics; Condensed Matter, 2, p.8525 - 8535, 1990/00
Times Cited Count:5 Percentile:38.2(Physics, Condensed Matter)no abstracts in English