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Honda, Mitsunori; Kaneta, Yui; Muraguchi, Masakazu*; Hayakawa, Kosetsu*; Oda, Masato*; Iino, Chiaki*; Ishii, Hiroyuki*; Goto, Takuya*
AIP Advances (Internet), 14(5), p.055034_1 - 055034_6, 2024/05
Times Cited Count：0 Percentile：0.00(Nanoscience & Nanotechnology)This study examines the utilization of Fukushima weathered biotite(WB)as an alternative to conventional thermoelectric materials traditionally derived from rare and toxic substances. WB underwent milling, classification, and subsequent heat treatment via molten-salt treatment to produce crystals exhibiting conductivity akin to semiconductors within from 650
C to 850C range. Evaluation of WB and the derived crystal's electrical conductivity and Seebeck coefficient showcased their viability for high-temperature thermoelectric applications. Consequently, WB attained a dimensionless figure of merit (ZT) of 0.015, signaling its potential as a thermoelectric material that surpasses 650C.
Honda, Mitsunori; Kaneta, Yui; Yaita, Tsuyoshi
AIP Advances (Internet), 13(1), p.015314_1 - 015314_6, 2023/01
Times Cited Count：1 Percentile：14.50(Nanoscience & Nanotechnology)The efficiency of the sorption of Sr
on weathered biotite, a type of clay minerals was investigated. Removal of Sr and Cs
is important in the treatment of contaminated water from the 1F accident, which is one of the radionuclide waste treatment problems. We focused on developing an adsorption method for Sr ions using weathered biotite, which are abundant in Fukushima. Applying a molten salt treatment, the amount of sorbed Sr simply increased as the added mass ratio of strontium chloride (SrCl
) increased from 1:1, 1:5, and 1:10 for the one-fold, five-fold, and ten-fold additions of SrCl, respectively. Then, the crystal structure of weathered biotite as an adsorbent was evaluated by X-ray diffraction (XRD) analysis. Thus, it was observed that the WB retained its original crystal structure even after the sorption of Sr. Extended X-ray absorption fine structure (EXAFS) analysis was performed to investigate the local sorption structure of Sr in the WB. The results revealed that Sr was preferentially sorbed into the SiO
and AlO
layers when Sr was in the low mass ratio, while, it was mainly sorbed into the SiO layer when the ratio was high.
Entani, Shiro*; Sato, Shinichiro*; Honda, Mitsunori; Suzuki, Chihiro*; Taguchi, Tomitsugu*; Yamamoto, Shunya*; Oshima, Takeshi*
Radiation Physics and Chemistry, 199, p.110369_1 - 110369_7, 2022/10
Times Cited Count：1 Percentile：15.53(Chemistry, Physical)Ni silicide synthesis by Ni ion beam irradiation into Si attracts attention due to its advantages including the ability of formation of local structures, the controllability of ion beams, the formability of silicide without heat treatment and the high reproducibility of the resulting specimen. In this work, we investigate the local atomic structure of Si implanted with 3.0 MeV Ni ions. Analysis of Ni K-edge fluorescent-yield extended X-ray absorption fine structure reveals that Ni atoms have mixed structure of metallic-like face-centered cubic Ni and NiSi phases at the initial stage of the irradiation and the formation of NiSi promotes significantly with the ion fluence above 10 
ions cm
. With consideration of the agreement between the ion fluence threshold for the structural transition and the critical Si-amorphization fluence, it is concluded that the amorphization of Si plays an important role in the synthesis of the NiSi phase in Ni-irradiated Si.
Matsuda, Shohei; Yokoyama, Keiichi; Yaita, Tsuyoshi; Kobayashi, Toru; Kaneta, Yui; Simonnet, M.; Sekiguchi, Tetsuhiro; Honda, Mitsunori; Shimojo, Kojiro; Doi, Reisuke; et al.
Science Advances (Internet), 8(20), p.eabn1991_1 - eabn1991_11, 2022/05
Times Cited Count：8 Percentile：43.80(Multidisciplinary Sciences)no abstracts in English
Iwata, Keiko; Takamizawa, Hisashi; Ha, Yoosung; Shimodaira, Masaki; Okamoto, Yoshihiro; Honda, Mitsunori; Katsuyama, Jinya; Nishiyama, Yutaka
Nuclear Instruments and Methods in Physics Research B, 511, p.143 - 152, 2022/01
Times Cited Count：2 Percentile：33.33(Instruments & Instrumentation)
-AlO(0001)Entani, Shiro*; Honda, Mitsunori; Naramoto, Hiroshi*; Li, S.*; Sakai, Seiji*
Surface Science, 704, p.121749_1 - 121749_6, 2021/02
Times Cited Count：6 Percentile：34.30(Chemistry, Physical)Graphene is expected to be one of the most promising materials for nanoelectronics and spintronics. In most graphene-based devices, the graphene channel is placed on insulating substrates. Therefore, the study of inter-facial interactions between graphene and the insulator surface is of critical importance. In this study, the vertical arrangement of graphene which is transferred on -AlO(0001) has been studied by normal incidence X-ray standing wave (NIXSW) technique. The analysis of the NIXSW profile reveals that the graphene layer is located at 3.57 (
) above the -AlO(0001) surface, which is larger than the interlayer distance of graphite at 3.356 (). Micro- Raman spectroscopy shows that the transferred graphene has a limited spatial distribution of hole concentration. The present study shows that transferred graphene on the sapphire substrate followed by vacuum-annealing has an atomically flat surface free from residual contaminations such as organic compounds and there occurs the hole-doping in graphene.
Honda, Mitsunori; Goto, Takuya*; Sakanaka, Yoshihide*; Yaita, Tsuyoshi; Suzuki, Shinichi*
AIMS Electronics and Electrical Engineering (Internet), 3(2), p.102 - 110, 2019/03
The possibility of removal and controlling crystal formation from weathered biotite (WB) in clay minerals were investigated using molten salt electrochemistry (EC) in molten NaCl-CaCl under an electrochemical reductive reaction. Cyclic Voltammogram (CV) measurements were performed in the range of +0.5 V to -2.2 V. Several peaks were confirmed in the CV spectra. The peak at -1.4 V represents a reduction reaction of Fe in WB, so we conducted an experiment at -1.4 V for 2 h to reduce Iron (Fe). The Cs removal rate after EC treatment was determined by X-ray fluorescence analysis, and almost 100% Cs removal was confirmed. To understand the effect of the reductive reaction, we performed X-ray Adsorption Fine Structure (XAFS) analysis. Before EC treatment, the Fe in WB was present as a mixture of Fe
and Fe. After EC treatment, the presence of Fe was confirmed by XAFS analysis. Based on this finding, EC treatment is effective for reducing Fe in WB. This result indicated that FeO formation was suppressed, and the reduction reaction was effective for controlling crystal formation.
Entani, Shiro*; Honda, Mitsunori; Shimoyama, Iwao; Li, S.*; Naramoto, Hiroshi*; Yaita, Tsuyoshi; Sakai, Seiji*
Japanese Journal of Applied Physics, 57(4S), p.04FP04_1 - 04FP04_4, 2018/04
Times Cited Count：3 Percentile：12.70(Physics, Applied)Iwata, Keiko; Takamizawa, Hisashi; Ha, Yoosung; Okamoto, Yoshihiro; Shimoyama, Iwao; Honda, Mitsunori; Hanawa, Satoshi; Nishiyama, Yutaka
Photon Factory Activity Report 2017, 2 Pages, 2018/00
no abstracts in English
Honda, Mitsunori; Shimoyama, Iwao; Kogure, Toshihiro*; Baba, Yuji; Suzuki, Shinichi; Yaita, Tsuyoshi
ACS Omega (Internet), 2(12), p.8678 - 8681, 2017/12
Times Cited Count：9 Percentile：29.65(Chemistry, Multidisciplinary)Yaita, Tsuyoshi; Honda, Mitsunori; Shimoyama, Iwao; Ito, Kenichi*; Mampuku, Yuzo*; Tsuji, Takuya; Matsumura, Daiju
Nihon Genshiryoku Gakkai-Shi ATOMO
, 59(8), p.483 - 487, 2017/08
no abstracts in English
Shimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Hirao, Norie*; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
Photon Factory News, 35(1), p.17 - 22, 2017/05
We introduce Cs-free mineralization (CFM) for Cs removal and reuse of radioactive-contaminated soil in Fukushima and report recent work conducted in the BL27A beamline in Photon Factory. In this work, we investigated compositional and structural changes of Cs-sorbed weathered biotite (WB) before and after heating treatment with addition of NaCl-CaCl salts under low-pressure condition, to study Cs desorption mechanism from clay minerals. X-ray fluorescence spectroscopy clarified that almost all Cs and K were removed with the salts at 700 C. On the other hand, Ca increased with heating temperature. X-ray diffraction and transmission electron microscopy analysis clarified that phase transitions from WB to some Ca-rich silicate minerals, e.g., augite, were caused by the heating treatment with the salt. Based on these results, CFM is proposed for Cs removal utilizing the mechanism in which large monovalent cations are discharged with accompanying the phase transition. We also discuss the role of Cl in this reaction showing chemical bonding change of Cl observed using X-ray absorption spectroscopy in the early stage of the chemical reaction.
mixed saltHonda, Mitsunori; Okamoto, Yoshihiro; Shimoyama, Iwao; Shiwaku, Hideaki; Suzuki, Shinichi; Yaita, Tsuyoshi
ACS Omega (Internet), 2(2), p.721 - 727, 2017/02
Times Cited Count：20 Percentile：53.11(Chemistry, Multidisciplinary)
3 absorption edge for cesium sorbed in clay mineralsHonda, Mitsunori; Shimoyama, Iwao; Okamoto, Yoshihiro; Baba, Yuji; Suzuki, Shinichi; Yaita, Tsuyoshi
Journal of Physical Chemistry C, 120(10), p.5534 - 5538, 2016/03
Times Cited Count：21 Percentile：54.23(Chemistry, Physical)Honda, Mitsunori; Shimoyama, Iwao; Baba, Yuji; Suzuki, Shinichi; Okamoto, Yoshihiro; Yaita, Tsuyoshi
e-Journal of Surface Science and Nanotechnology (Internet), 14, p.35 - 38, 2016/02
Sekiguchi, Tetsuhiro; Baba, Yuji; Hirao, Norie; Honda, Mitsunori; Izumi, Toshinori; Ikeura, Hiromi*
Molecular Crystals and Liquid Crystals, 622(1), p.44 - 49, 2015/12
Times Cited Count：0 Percentile：0.00(Chemistry, Multidisciplinary)The molecular orientation is one of the important factors for controlling various properties in organic semiconductor materials. Films are usually heterogeneous. Thus they exist as a mixture of microscopic domains which have a variety of orientation directions. Therefore, it is essential to observe selectively microscopic domains with different orientation direction. In this work, we have developed the photoelectron emission microscopy (PEEM) system combined with the linearly polarized vacuum ultraviolet (VUV) light or synchrotron radiation (SR) X-rays. PEEM images (FOV = ca.50 micro m) for poly(3-hexylthiophene), P3HT thin films were observed under the UV irradiation with various polarization angles, including in-plain and out-of-plain polarization. Morphologies at some bright parts are different each other. The resultant observation suggests that it enables us to distinguish oriented micro-domains with specific directions of polymer chain axis from other amorphous parts.
Toma, Mitsunori; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Honda, Mitsuru; Ide, Shunsuke
Plasma Physics and Controlled Fusion, 57(9), p.095007_1 - 095007_9, 2015/09
Times Cited Count：4 Percentile：17.14(Physics, Fluids & Plasmas)Integrated tokamak modelling that enables the simulation of an entire discharge periodis indispensable for designing advanced tokamak plasmas. For this purpose, we extend the integrated code TOPICS to make it more suitable for transient analyses in the fast-ion part. The fast-ion Fokker-Planck solver is integrated into TOPICS at the same level as the bulk transport solver so that the time evolutions of the fast ion and the bulk plasma are consistent with each other as well as with the equilibrium magnetic field. The integrated code is applied to ramp-up simulations for JT-60SA and ITER to confirm its capability and effectiveness in transient analyses. In the integrated simulations, the coupled evolution of the fast ions, plasma profiles, and equilibrium magnetic fields are presented.
Hayashi, Nobuhiko; Honda, Mitsuru; Shiraishi, Junya; Miyata, Yoshiaki; Wakatsuki, Takuma; Hoshino, Kazuo; Toma, Mitsunori; Suzuki, Takahiro; Urano, Hajime; Shimizu, Katsuhiro; et al.
Europhysics Conference Abstracts (Internet), 39E, p.P5.145_1 - P5.145_4, 2015/06
Honda, Mitsunori; Baba, Yuji; Shimoyama, Iwao; Sekiguchi, Tetsuhiro
Review of Scientific Instruments, 86(3), p.035103_1 - 035103_5, 2015/03
Times Cited Count：12 Percentile：45.85(Instruments & Instrumentation)Honda, Mitsunori; Yanagida, Masatoshi*; Han, L.*; Miyano, Kenjiro*
Journal of Chemical Physics, 141(17), p.174709_1 - 174709_7, 2014/11
Times Cited Count：9 Percentile：31.21(Chemistry, Physical)
