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Sr
NiO
Kajimoto, Ryoichi; Fujita, Masaki*; Nakajima, Kenji; Ikeuchi, Kazuhiko*; Inamura, Yasuhiro; Nakamura, Mitsutaka; Imasato, Takuro*
Journal of Physics; Conference Series, 502(1), p.012056_1 - 012056_5, 2014/04
Times Cited Count：1 Percentile：53.76(Materials Science, Multidisciplinary)
Yoneda, Yasuhiro; Fu, D.*; Kohara, Shinji*
Journal of Physics; Conference Series, 502(1), p.012022_1 - 012022_4, 2014/04
Times Cited Count：12 Percentile：97.58(Materials Science, Multidisciplinary)NaNbO has an antiferroelectric structure at room temperature and finds important technological applications. It exhibits an unusual complex sequence of temperature- and pressure-driven structural phase transitions. NaNbO shows unambiguous evidence for the presence of the ferroelectric 
phase coexisting with an antiferroelectric phase (
) over a wide range of temperatures. We have carried out atomic pair-distribution function (PDF) analysis on NaNbO to understand the phase transitions. High-energy X-ray PDF using powder samples were carried out at the SPring-8, which is provided to become rhombohedral structure if 
-site atoms did order and to become antiferroelectric phase if -site atoms did disorder.
Fujii, Kentaro; Narita, Ayumi; Yokoya, Akinari
Journal of Physics; Conference Series, 502(1), p.012034_1 - 012034_4, 2014/04
In order to clarify the unoccupied electronic structure exposed to soft X-rays, we measured XANES spectrum of adenosine 5'-triphosphate (ATP) before and after irradiation. Experiments were performed at soft X-ray beamline BL23SU in SPring-8. We observed the spectral changes of the resonant peak near nitrogen and oxygen K-ionization thresholds by an irradiation with 560 eV photons which is above oxygen ionization potential. Irradiated samples were also analyzed by electrochemistry and mass spectrometry. Decomposition patterns of ATP exposed to soft X-ray will be discussed from these results.
-edge soft X-ray natural circular dichroism of histidine thin filmIzumi, Yudai; Tanaka, Masahito*; Tanigawa, Yoshiaki*; Tanabe, Maiko*; Momoki, Yohei*; Iwai, Miki*; Takenaka, Shun*; Ishiyama, Kimihiro*; Kuroki, Misa*; Muro, Takayuki*; et al.
Journal of Physics; Conference Series, 502(1), p.012038_1 - 012038_4, 2014/04
Times Cited Count：2 Percentile：72.7(Materials Science, Multidisciplinary)Sugaya, Yuki; Narita, Ayumi; Fujii, Kentaro; Yokoya, Akinari
Journal of Physics; Conference Series, 502(1), p.012040_1 - 012040_4, 2014/04
Times Cited Count：0 Percentile：0.07(Materials Science, Multidisciplinary)Onishi, Hiroaki
no journal, ,
Fukaya, Yuki; Mochizuki, Izumi*; Maekawa, Masaki; Wada, Ken*; Hyodo, Toshio*; Kawasuso, Atsuo
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
O (R: rare earths)Yoshii, Kenji; Matsumura, Daiju; Endo, Naruki; Saito, Hiroyuki; Yoneda, Yasuhiro; Nishihata, Yasuo; Funae, Takeshi*; Ejiri, Hiroki*; Kano, Jun*; Kobayashi, Tatsuo*; et al.
no journal, ,
We have investigated the substitution effects at the rare-earth (R) site in multiferroic RFeO (R: Y, Ho-Lu) to explore a new phase of this system. From EXAFS measurements for the R atoms, the large R
ions (such as Dy) was partially substituted in RFeO. Powder X-ray diffraction showed that this material had a single-phase RFeO-type structure (space group R-3m). The simulated EXAFS spectrum reproduced the characteristics of the experimental spectrum, confirming that R is actually settled at the rare earth site. The other results, such as the magnetic properties, will be reported at the conference.
Sugimoto, Takanori; Mori, Michiyasu; Toyama, Takami; Maekawa, Sadamichi
no journal, ,
Sakaguchi, Yoshifumi*; Asaoka, Hidehito; Uozumi, Yuki; Kawakita, Yukinobu; Ito, Takayoshi*; Kubota, Masato; Yamazaki, Dai; Soyama, Kazuhiko; Ailavajhala, M.*; Mitkova, M.*
no journal, ,
Silver photo-diffusion is one of the attractive phenomena observed in amorphous chalcogenide films such as As2S3 and GeSe2 because of their potential applications in, for example, photo-lithography, memory devices, and fabrication of optical elements. We report the results of neutron reflectivity measuremens for silver photo-diffusion in Ag/Ge-S films under light illumination. The neutron reflectivity measurements have been performed on a polarized neutron reflectometer (BL17, SHARAKU) at Materials and Life Science Experimental Facility (MLF), Japan Proton Accerelator Research Complex (J-PARC), Japan. By using the time-of-flight instrument with intensive pulsed neutrons produced by 300kW proton beams and sophisticated event recording system, time evolution of the neutron reflectivity under a light illumination has been revealed with, at least, 2-min time resolution. The reaction rate by the light illumination is discussed based on the detailed analysis of the time-resolved neutron reflectivity results.
Tominaga, Taiki; Takata, Shinichi; Suzuki, Junichi*; Aizawa, Kazuya; Seto, Hideki; Arai, Masatoshi
no journal, ,
no abstracts in English
Katayama, Yoshinori; Saito, Hiroyuki; Aoki, Katsutoshi
no journal, ,
To study melting behavior and structure of liquid 3d transition metal-hydrogen alloys, we have performed X-ray diffraction measurements under high-pressure high-temperature conditions for hydrogenated Ti, V, Mn, Fe, Co and Ni. Experiments were performed using a cubic-type multi-anvil press installed on BL14B1 at SPring-8. Starting materials were TiH and VH for Ti and V, respectively, and pure metals for Mn, Fe, Co and Ni. The sample was put in a capsule made of pyrolytic BN and then inserted in a NaCl capsule together with hydrogen source. The sample was heated at about 4 GPa. We did not observe any indications of melting for TiH and VH while we observed liquid pattern for hydrogenated Mn, Fe, Co and Ni. The decrease of melting temperature was confirmed for Fe, Co and Ni. The nearest neighbor distance between the metal atoms elongated due to the hydrogenation.
Machida, Akihiko; Hattori, Takanori; Sano, Asami; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi; Oshita, Hidetoshi*; Ikeda, Kazutaka*; Otomo, Toshiya*
no journal, ,
Structural properties of metal hydrides have been investigated by using synchrotron radiation (SR) X-rays at SPring-8 and neutrons at J-PARC, Japan. We have focused on the interactions between interstitial hydrogen atoms and their surrounding atoms. The hydrogen-metal interactions provide the important knowledge to develop the high performance hydrogen storage materials. High pressure technique is useful for producing highly densified metal hydride, in which the metal and hydrogen atoms approach closer and their interactions become pronounced. Recently, we found that lanthanum dihydride decomposed into two different phases at high pressure and discovered the NaCl-type monohydride, which was formed by decomposition. This result indicates that the nature of the hydrogen-metal interactions significantly change by pressurization. Our findings will open the way for studying the site-dependent nature of hydrogen-metal interactions.
(110) surfaces studied by high-brightness reflection high-energy positron diffractionMochizuki, Izumi*; Ariga, Hiroko*; Fukaya, Yuki; Wada, Ken*; Hyodo, Toshio*; Asakura, Kiyotaka*; Maekawa, Masaki; Kawasuso, Atsuo
no journal, ,
no abstracts in English
Narita, Ayumi; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie; Yaita, Tsuyoshi
no journal, ,
Self-assembled monolayer (SAM) with alkyl chains has widely been studied because the alkyl SAM can be used as a mold to immobilize the other organic functional molecules. In this study, we investigate the immobilization of alkyl chain molecules on metal and oxide surfaces with controlling the direction of the alkyl chain. Mercapto-propyl-trimetoxy-silane (MPTS) molecules (HS(CH)
Si(OCH)) which have thiol group (SH) and silicon alkoxide group (Si(OCH)) at the terminal sites of the alkyl backbone was adsorbed on Au and sapphire surfaces. The samples were measured by X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS). As a result, MPTS molecules are adsorbed on Au with thiol groups and alkoxide groups are located at the upper side, while the direction of MPTS molecules on sapphire surface is opposite.
Suzuya, Kentaro; Oshita, Hidetoshi*; Otomo, Toshiya*; Ikeda, Kazutaka*; Seya, Tomohiro*; Kaneko, Naokatsu*; Fujisaki, Fumika*
no journal, ,
NOVA has almost 900 3-helium gas detectors for neutron diffraction measurements. Two Gas Electron Multiplier (GEMs) are installed as an incident-neutron and a transmission beam monitors. The performance of NOVA has been confirmed by several samples: structural analysis of crystalline and amorphous samples are demonstrated, the instrument background is low enough to measure S(Q) with the order of several ten mg for an hour. Typical S(Q) of silica glass (cylindrical rod, 20 mm long, and 7 mm diameter) is obtained up to 15 (1/
) for 1 sec and up to 35 (1/) for 20 sec. These results show that NOVA is a powerful instrument for in situ dynamic investigation of rapid structural transformation in supercooled liquids and in hydrogen storage materials. Some of recent results of disordered materials on NOVA will be presented.
Arai, Masatoshi
no journal, ,
J-PARC MLF is a 1 MW spallation neutron source. The averaged neutron flux is about 1/4 of ILL research reactor, the world best reactor. However, the pulse peak flux can exceed 100 times that of ILL. Present power of the proton accelerator is 300 kW with a very stable operation, 94% world-level stability. It is planned to increase the power to be 500 kW after the long summer shutdown. 16 instruments are available for user program now. Operational time for user program in 2012 was about 180 days, and we have received more than 550 experimental proposals from 900 users. World-class scientific outputs have been already created in various scientific fields. Since J-PARC is internationally open for users, we have got experimental proposals from abroad more than 10% of the whole proposals. More than 30% of proposals have come from industries. This fact has revealed a new horizon come in the neutron scattering science in the 21 century.
