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Kawasaki, Takuro; Fukuda, Tatsuo; Yamanaka, Satoru*; Murayama, Ichiro*; Kato, Takanori*; Baba, Masaaki*; Hashimoto, Hideki*; Harjo, S.; Aizawa, Kazuya; Tanaka, Hirohisa*; et al.
Journal of Applied Physics, 137(9), p.094101_1 - 094101_7, 2025/03
Yoshimune, Wataru*; Higuchi, Yuki*; Song, F.; Hibi, Shogo*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Shinohara, Takenao; Kato, Satoru*
Physical Chemistry Chemical Physics, 26(47), p.29466 - 29474, 2024/11
Times Cited Count：1 Percentile：58.13(Chemistry, Physical)Higuchi, Yuki*; Yoshimune, Wataru*; Kato, Satoru*; Hibi, Shogo*; Setoyama, Daigo*; Isegawa, Kazuhisa*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Harada, Masashi*; et al.
Communications Engineering (Internet), 3, p.33_1 - 33_7, 2024/02
Yoshimune, Wataru*; Higuchi, Yuki*; Kato, Akihiko*; Hibi, Shogo*; Yamaguchi, Satoshi*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Nozaki, Hiroshi*; Shinohara, Takenao; Kato, Satoru*
ACS Energy Letters (Internet), 8(8), p.3485 - 3487, 2023/08
Times Cited Count：12 Percentile：82.74(Chemistry, Physical)
structure observation of pyroelectric ceramics during power generation cycleKawasaki, Takuro; Fukuda, Tatsuo; Yamanaka, Satoru*; Sakamoto, Tomokazu*; Murayama, Ichiro*; Kato, Takanori*; Baba, Masaaki*; Hashimoto, Hideki*; Harjo, S.; Aizawa, Kazuya; et al.
Journal of Applied Physics, 131(13), p.134103_1 - 134103_7, 2022/04
Times Cited Count：1 Percentile：8.43(Physics, Applied)Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：7 Percentile：42.16(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：53 Percentile：96.13(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
O)
]
with nitrate ions by using density functional theory calculationKato, Akane*; Kaneko, Masashi; Nakashima, Satoru*
RSC Advances (Internet), 10(41), p.24434 - 24443, 2020/06
Times Cited Count：7 Percentile：25.48(Chemistry, Multidisciplinary)Complexation reactions of ruthenium-nitrosyl complexes in HNO
solution were investigated by density functional theory (DFT) calculations in order to predict the stability of Ru species in high-level radioactive liquid waste (HLLW) solution. Equilibrium structure of [Ru(NO)(NO)(HO)] obtained by DFT calculations reproduced the experimental Ru-ligands bond lengths and IR frequencies reported previously. Comparison of the Gibbs energies among the geometrical isomers revealed that the complexation reactions of the ruthenium-nitrosyl complexes with NO
proceed via the NO coordination to the equatorial plane toward the Ru-NO axis. We also estimated Gibbs energy differences on the stepwise complexation reactions to succeed in reproducing the fraction of Ru-NO species in 6 M HNO solution, such as in HLLW, by considering the association energy between the Ru-NO species and the substituting ligands. Electron density analyses of the complexes indicated that the strength of the Ru-ligands coordination bonds depends on the stability of the Ru species and the Ru complex without NO at the axial position is more stable than that wit NO, which might attribute to the difference in the trans influence between HO and NO. Finally, we demonstrated the complexation kinetics in the reactions 
. The present study is expected to enable us to model the precise complexation reactions of platinum-group metals in HNO solution.
Kim, J.*; Yamanaka, Satoru*; Murayama, Ichiro*; Kato, Takanori*; Sakamoto, Tomokazu*; Kawasaki, Takuro; Fukuda, Tatsuo; Sekino, Toru*; Nakayama, Tadachika*; Takeda, Masatoshi*; et al.
Sustainable Energy & Fuels (Internet), 4(3), p.1143 - 1149, 2020/03
Times Cited Count：20 Percentile：64.19(Chemistry, Physical)
Ru M
ssbauer parameters of ruthenium-nitrosyl complexesKaneko, Masashi; Kato, Akane*; Nakashima, Satoru*; Kitatsuji, Yoshihiro
Inorganic Chemistry, 58(20), p.14024 - 14033, 2019/10
Times Cited Count：12 Percentile：57.72(Chemistry, Inorganic & Nuclear)We applied density functional theory calculations to ruthenium-nitrosyl complexes, which are known to exist in high-level radioactive waste, to give a theoretical correlation between Ru Mssbauer spectroscopic parameters (
and 
) and ligand field strength (
) for the first time. The structures of the series of complexes, [Ru(NO)L] (L = Br, Cl, NH, CN), were modeled based on the corresponding single-crystal X-ray coordinates. The comparisons of the geometries and total energies between the different spin states suggested that the singlet spin state of [Ru(II)(NO
)L] complexes were the most stable. The calculated results of both the and values reproduced the experimental results by reported previously and increased in the order of L = Br, Cl, NH, CN. Finally, we estimated the ligand field strength () based on molecular orbitals, assuming C
symmetry and showed the increase of values in that order, being consistent with well-known spectrochemical series of ligands. The increase attributes to the strengthening of the abilities of 
-donor and 
-acceptor of the L-ligands to the Ru atom, resulting in the increase of the values.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.
Science, 364(6437), p.272 - 275, 2019/04
Times Cited Count：285 Percentile：99.69(Multidisciplinary Sciences)The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.
Kim, J.*; Yamanaka, Satoru*; Nakajima, Akira*; Kato, Takanori*; Kim, Y.*; Fukuda, Tatsuo; Yoshii, Kenji; Nishihata, Yasuo; Baba, Masaaki*; Takeda, Masatoshi*; et al.
Advanced Sustainable Systems (Internet), 2(11), p.1800067_1 - 1800067_8, 2018/11
Times Cited Count：7 Percentile：24.96(Green & Sustainable Science & Technology)Moro, Takuya*; Kim, J.*; Yamanaka, Satoru*; Murayama, Ichiro*; Kato, Takanori*; Nakayama, Tadachika*; Takeda, Masatoshi*; Yamada, Noboru*; Nishihata, Yasuo; Fukuda, Tatsuo; et al.
Journal of Alloys and Compounds, 768, p.22 - 27, 2018/11
Times Cited Count：17 Percentile：60.79(Chemistry, Physical)Kato, Masaru*; Muto, Marika*; Matsubara, Naohiro*; Uemura, Yohei*; Wakisaka, Yuki*; Yoneuchi, Tsubasa*; Matsumura, Daiju; Ishibara, Tomoko*; Tokushima, Takashi*; Noro, Shinichiro*; et al.
ACS Applied Energy Materials (Internet), 1(5), p.2358 - 2364, 2018/05
Times Cited Count：14 Percentile：44.07(Chemistry, Physical)Kim, J.*; Yamanaka, Satoru*; Nakajima, Akira*; Kato, Takanori*; Kim, Y.*; Fukuda, Tatsuo; Yoshii, Kenji; Nishihata, Yasuo; Baba, Masaaki*; Takeda, Masatoshi*; et al.
Ferroelectrics, 512(1), p.92 - 99, 2017/08
Times Cited Count：14 Percentile：52.91(Materials Science, Multidisciplinary)Yamanaka, Satoru*; Kim, J.*; Nakajima, Akira*; Kato, Takanori*; Kim, Y.*; Fukuda, Tatsuo; Yoshii, Kenji; Nishihata, Yasuo; Baba, Masaaki*; Yamada, Noboru*; et al.
Advanced Sustainable Systems (Internet), 1(3-4), p.1600020_1 - 1600020_6, 2017/04
no abstracts in English
Matsunami, Noriaki*; Ito, M.*; Kato, M.*; Okayasu, Satoru; Sataka, Masao*; Kakiuchida, Hiroshi*
Nuclear Instruments and Methods in Physics Research B, 365(Part A), p.191 - 195, 2015/12
Times Cited Count：7 Percentile：48.30(Instruments & Instrumentation)We have studied ion impact effects on atomic structure in terms of X-ray diffraction (XRD), optical absorption and electrical resistivity of Mn (6%)-doped ZnO films under 100 MeV Xe ion impact at room temperature. We find the monotonic reduction of the XRD intensity to 1/50 of that of unirradiated film at 5 
10
cm
, little bandgap change (
0.02 eV) and decrease of the resistivity by 4 order of magnitude. The resistivity modification has been compared with that by irradiations of low energy ions such as 100 keV Ne and N, which show more effective decrease of resistivity. We also find that temperature (T) dependence of the magnetic susceptibility (
) of Mn-doped ZnO follows the Curie law: = 
+ C/T (i.e., paramagnetic) and the Curie constant C decreases to a half of that before irradiation (C
= 0.012 emu cm
K) at 100 MeV Xe ion fluence of 10
cm.
Osakabe, Toyotaka; Kato, Yoshihiro*; Honmoto, Satoru*; Kuwahara, Keitaro*
Koatsuryoku No Kagaku To Gijutsu, 25(1), p.57 - 63, 2015/03
In this article, we describe an unique technique for electrical insulation of metallic gasket to perform simultaneous measurements of electrical resistivity and neutron diffraction under high pressure. The anodic oxide coating was adopted as the insulation layer of the aluminum (JIS A2017) gasket used in the hybrid-anvil device for neutron diffraction. In the feasibility tests of the coated gaskets, maximum pressure of about 6 GPa was generated without electrical breakdown of the coating or disconnection of Au leads.
thin film detector for neutronsIshida, Takekazu*; Nishikawa, Masatoshi*; Fujita, Yoshifumi*; Okayasu, Satoru; Katagiri, Masaki*; Sato, Kazuo*; Yotsuya, Tsutomu*; Shimakage, Hisashi*; Miki, Shigehito*; Wang, Z.*; et al.
Journal of Low Temperature Physics, 151(3-4), p.1074 - 1079, 2008/05
Times Cited Count：38 Percentile：78.35(Physics, Applied)The superconducting neutron detector using high-quality 
B-enriched MgB thin films at higher operating temperatures has been proposed, where a resistance change induced by the nuclear reaction of neutron and B in MgB is used to detect a neutron. Cold neutrons from a nuclear research reactor irradiated the MgB detector, and the output voltage was clearly observed through a low-noise amplifier by using a digital oscilloscope. The out-of-equilibrium thermodynamics was investigated by means of the time-dependent Ginzburg-Landau equations by using the Earth Simulator.
Tsuchiya, Kunihiko; Hoshino, Tsuyoshi; Kawamura, Hiroshi; Mishima, Yoshinao*; Yoshida, Naoaki*; Terai, Takayuki*; Tanaka, Satoru*; Munakata, Kenzo*; Kato, Shigeru*; Uchida, Munenori*; et al.
Nuclear Fusion, 47(9), p.1300 - 1306, 2007/09
Times Cited Count：23 Percentile：60.87(Physics, Fluids & Plasmas)no abstracts in English
