Fukumitsu, Nobuyoshi*; Yamauchi, Yusuke*; Saptiama, I.*; Ariga, Katsuhiko*; Hatano, Kentaro*; Kumada, Hiroaki*; Fujita, Yoshitaka; Tsuchiya, Kunihiko
Isotope News, (760), p.15 - 18, 2018/12
no abstracts in English
Amekura, Hiroshi*; Kluth, P.*; Mota-Santiago, P.*; Sahlberg, I.*; Jantunen, V.*; Leino, A. A.*; Vazquez, H.*; Nordlund, K.*; Djurabekova, F.*; Okubo, Nariaki; et al.
Physical Review Materials (Internet), 2(9), p.096001_1 - 096001_10, 2018/09
When a swift heavy ion (SHI) penetrates amorphous SiO, a core/shell (C/S) ion track is formed due to vaporization, where the ion track consists of a lower-density core and a higher-density shell. Here we reexamine this hypothesis. The MD simulations indicate that the vaporization is not induced under 50-MeV Si irradiation ( = 3 keV/nm), but the C/S tracks and the ion shaping of nanoparticles are nevertheless induced. Thus, the vaporization is not a prerequisite for the C/S tracks and the ion shaping.
Saptiama, I.*; Kaneti, Y. V.*; Suzuki, Yoshitaka; Tsuchiya, Kunihiko; Fukumitsu, Nobuyoshi*; Sakae, Takeji*; Kim, J.*; Kang, Y.-M.*; Ariga, Katsuhiko*; Yamauchi, Yusuke*
Small, 14(21), p.1800474_1 - 1800474_14, 2018/05
no abstracts in English
Fukushima, Yoshiaki*; Yamada, Takeshi*; Tamura, Kenji*; Shibata, Kaoru
Applied Clay Science, 155, p.15 - 19, 2018/04
Dynamics of a fluoromica (ME100) cation exchanged for dioctadecyl dimethyl ammonium ion (DODA)/ polypropylene composite was analyzed by quasi elastic neutron scattering (QENS), besides XRD and DSC. The QENS spectra for the DODA-ME100 at low Q=2.75 nm were not changed even at temperature higher than 445 K, the melting point of DODA. The results suggested the long range ( 2 nm) molecular motions in interlayer space are restricted due to the rigid silicate layers and the strong electrostatic interaction between DODA and the ME100. Elastic intensity scan results suggested that a little amount of motion of the polymer chains in the composite was also restricted in the molten state at 445 K. The QENS is expected to be one of the useful tools for studying the composite materials.
Saptiama, I.*; Kaneti, Y. V.*; Oveisi, H.*; Suzuki, Yoshitaka; Tsuchiya, Kunihiko; Takai, Kimiko*; Sakae, Takeji*; Pradhan, S.*; Hossain, M. S. A.*; Fukumitsu, Nobuyoshi*; et al.
Bulletin of the Chemical Society of Japan, 91(2), p.195 - 200, 2018/02
no abstracts in English
Saptiama, I.*; Kaneti, Y. V.*; Suzuki, Yumi*; Suzuki, Yoshitaka; Tsuchiya, Kunihiko; Sakae, Takeji*; Takai, Kimiko*; Fukumitsu, Nobuyoshi*; Alothman, Z. A.*; Hossain, M. S. A.*; et al.
Bulletin of the Chemical Society of Japan, 90(10), p.1174 - 1179, 2017/10
no abstracts in English
Fugane, Keisuke*; Mori, Toshiyuki*; Yan, P.*; Masuda, Takuya*; Yamamoto, Shunya; Ye, F.*; Yoshikawa, Hideki*; Auchterlonie, G.*; Drennan, J.*
ACS Applied Materials & Interfaces, 7(4), p.2698 - 2707, 2015/02
no abstracts in English
Xu, Y.*; Ma, Y.*; Sakurai, Junya*; Teraoka, Yuden; Yoshigoe, Akitaka; Demura, Masahiko*; Hirano, Toshiyuki*
Applied Surface Science, 315, p.475 - 480, 2014/10
Kawae, Tatsuya*; Koga, Mikito*; Sato, Yoshiaki*; Makiyama, Shun*; Inagaki, Yuji*; Tateiwa, Naoyuki; Fujiwara, Tetsuya*; Suzuki, Hiroyuki*; Kitai, Tetsuo*
JPS Conference Proceedings (Internet), 3, p.012030_1 - 012030_6, 2014/06
We measure the temperature dependence of the nonlinear susceptibility in PrLaPb. reflects the fluctuation of the quadrupolar moments. Non-Fermi liquid behavior of with -dependence is detected below 2.5 K, suggesting that the screening of the quadrupolar moments is responsible for the anomalous behavior at low temperatures. These results provide a direct evidence for the crucial role of the quadrupolar moments in PrLaPb.
Fan, M.*; Xu, Y.*; Sakurai, Junya*; Demura, Masahiko*; Hirano, Toshiyuki*; Teraoka, Yuden; Yoshigoe, Akitaka
Catalysis Letters, 144(5), p.843 - 849, 2014/05
Kim, J.*; Fujiwara, Akihiko*; Sawada, Tomohiro*; Kim, Y.*; Sugimoto, Kunihisa*; Kato, Kenichi*; Tanaka, Hiroshi*; Ishikado, Motoyuki*; Shamoto, Shinichi; Takata, Masaki*
IUCrJ, 1(3), p.155 - 159, 2014/05
Using a charge density analysis based on synchrotron radiation X-ray powder diffraction data, we found that the charge carriers only accumulated in the iron layer of the superconducting phase of LaFeAsOF at low temperatures. Analysis of the electrostatic potential distribution revealed the concerted enhancement of the electronic polarization of the As ions and the carrier redistribution.
Osawa, Takahito; Kobayashi, Mikihiko*; Konno, Takeshi*; Egashira, Mitsuru*; Okazaki, Ryuji*; Miura, Yayoi*; Nagao, Keisuke*
Measurement, 50, p.229 - 235, 2014/04
A temperature control system for a laser heating has been developed to extract noble gases from minute material samples recovered from the asteroid Itokawa by the Hayabusa spacecraft. An ultra-fine thermocouple was produced from 3% Re-W and 26% Re-W wires 25 m in diameter, and its electromotive force was calibrated. A temperature control program was originally produced using LabVIEW 2011 in which proportional-integral-derivative (PID) control was not adopted as an algorithm of the program. The program controlled the temperature of the tiny samples appropriately. The average temperature during heating was slightly lower than the setting temperature and the standard deviation and the maximum overshoot were lower than 2.5% and 6.0% of the setting temperature, respectively. The performance of the temperature control system is high enough to conduct the stepwise heating experiment for minute extraterrestrial material samples.
Otomo, Manabu; Yamauchi, Yasushi*; Kuzubov, A. A.*; Eliseeva, N. S.*; Avramov, P.*; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi*; Sakai, Seiji
Applied Physics Letters, 104(5), p.051604_1 - 051604_4, 2014/02
Hexagonal boron nitride (h-BN) is a promising barrier material for graphene spintronics. In this study, spin-polarized metastable de-excitation spectroscopy (SPMDS) is employed to study the spin-dependent electronic structure of monolayer h-BN on Ni(111). The extreme surface sensitivity of SPMDS enables us to elucidate a partial filling of the in-gap states of h-BN without any superposition of Ni 3 signals. The in-gap states are shown to have a considerable spin polarization parallel to the majority spin of Ni. The positive spin polarization is attributed to the - hybridization and the effective spin transfer to the nitrogen atoms at the h-BN/Ni(111) interface.
Nakao, Yasuhiro*; Ozawa, Kiyoshi*; Fujii, Hiroki*; Mochiku, Takashi*; Iwai, Hideo*; Tsuchiya, Yoshinori*; Igawa, Naoki
Transactions of the Materials Research Society of Japan, 38(2), p.229 - 233, 2013/12
LiMnO powder with a monoclinic cell related to the space group of 2/ was synthesized by a simplified coprecipitation method. Its electrode properties as a lithium-battery cathode were investigated in the charge-discharge potential ranges of 2.0 - 4.6, 2.0 - 4.8, and 2.0 - 5.0 V. In all the potential ranges, the electrochemical capacities gradually increased during cycling, and the increased capacities significantly depended on the potential ranges. Compared to the discharge capacities for the potential ranges of 2.0 - 4.6 and 2.0 - 5.0 V, the former merely increased from 12.5 to 22.5 mAhg between the 1st and 99th cycles, whereas the latter increased from 20.0 to 110.2 mAhg during the same cycling. The structural variation in LiMnO is induced by the cycling, the rhombohedral phase is detected during cycling in the potential range of 2.0 - 5.0 V.
Entani, Shiro; Kurahashi, Mitsunori*; Sun, X.*; Yamauchi, Yasushi*
Carbon, 61, p.134 - 139, 2013/09
Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji; Oba, Yojiro*; Onuma, Masato*; Koyama, Shinichi; Tanaka, Kenya
Journal of Nuclear Materials, 440(1-3), p.568 - 574, 2013/09
This study carried out mechanical tests and microstructure characterizations of several 9Cr and 11Cr-ODS tempered martensitic steels, and discussed the appropriate chemical composition range of 11Cr-ODS tempered martensitic steel from the viewpoint of high-temperature strength improvement. It was shown that the residual -ferrite fraction in 11Cr-ODS steel was successfully controlled to the same level as the 9Cr-ODS steel by selecting the matrix chemical compositions on the basis of the multi-component phase diagram. The tensile strength decreased with decreasing W content from 2.0 to 1.4 wt%. On the other hand, creep strength at 973 K did not degrade by the decreasing W content. Both tensile strength and creep strength increased with increasing population of the nano-sized oxide particles. Small angle X-ray scattering analysis revealed that titanium and excess oxygen contents were key parameters in order to improve the dispersion condition of nano-sized oxide particles.
Okawa, Yukihisa*; Masuda, Takuya*; Uehara, Hiromitsu*; Matsumura, Daiju; Tamura, Kazuhisa; Nishihata, Yasuo; Uosaki, Kohei*
RSC Advances (Internet), 3(35), p.15094 - 15101, 2013/09
Masuda, Takuya*; Fukumitsu, Hitoshi*; Kondo, Toshihiro*; Naohara, Hideo*; Tamura, Kazuhisa; Sakata, Osami*; Uosaki, Kohei*
Journal of Physical Chemistry C, 117(23), p.12168 - 12171, 2013/06
The structure of the perfluorosulfonated ionomer (PFSI)/Pt(111) interface in a membrane electrode assembly (MEA)-like configuration of a polymer electrolyte membrane (PEM) fuel cell, that is, a vacuum evaporated Pt layer/PEM(Nafion membrane)/PFSI(adhesion Nafion layer)/Pt(111) single crystal, and its bias-induced change were investigated by surface X-ray scattering measurement at an atomic level. Crystal truncation rod measurement shows that PFSI adsorbed on the Pt(111)-(11) surface without bias. When the Pt(111) electrode was positively biased to form Pt oxide, the PFSI layer was detached from the Pt surface and oxygen atoms penetrated into the Pt lattice.
Hasegawa, Shin; Takahashi, Shuichi*; Iwase, Hiroki*; Koizumi, Satoshi; Onuma, Masato*; Maekawa, Yasunari
Polymer, 54(12), p.2895 - 2900, 2013/05
Radiation-induced graft polymerization of sulfo-containing styrene derivatives into crystalline poly(ether ether ketone) (PEEK) substrates was carried out to prepare thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer, so-called "super-engineering plastics". Graft polymerization of the sulfo-containing styrene, ethyl 4-styrenesulfonate (E4S) into PEEK substrates with degrees of crystallinity (DC) of 11 - 26% gradually progressed, achieving a grafting degree of more than 50% after 72 hours, whereas graft polymerization of the substrates with DC above 26% did not proceed. When morphological change in these films were measured by SAXS, PEEK films with DC larger than 26% showed a new peak at d=14 nm, corresponding to lamella structure. Thus, the suppression of graft polymerization of PEEK films with DC above 26% was due to obstruct of monomer diffusion by the formation of the oriented lamella structure.
Shamoto, Shinichi; Kodama, Katsuaki
JAEA-Review 2012-029, 264 Pages, 2012/08
Characteristic technologies, instruments, and distinguished researches of each institute about "Superconductivity, Magnetism and Phonon" are introduced and discussed on the basis of "Joint Research Agreement for the Pioneering R&D with Quantum Beam Technology" concluded by NIMS, RIKEN and JAEA in addition to research outcomes of this Joint Research Agreement including a future prospect of this research area. This report includes abstracts and materials of the presentations in the workshop.