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Yamashita, Keishiro*; Komatsu, Kazuki*; Ohara, Takashi; Munakata, Koji*; Irifune, Tetsuo*; Shimmei, Toru*; Sugiyama, Kazumasa*; Kawamata, Toru*; Kagi, Hiroyuki*
High Pressure Research, 42(1), p.121 - 135, 2022/03
Times Cited Count：1 Percentile：56.06(Physics, Multidisciplinary)
Kaneko, Koji; Kawasaki, Takuro; Nakamura, Ai*; Munakata, Koji*; Nakao, Akiko*; Hanashima, Takayasu*; Kiyanagi, Ryoji; Ohara, Takashi; Hedo, Masato*; Nakama, Takao*; et al.
Journal of the Physical Society of Japan, 90(6), p.064704_1 - 064704_6, 2021/06
Times Cited Count：26 Percentile：96.46(Physics, Multidisciplinary)
GeP
S
Yajima, Takeshi*; Hinuma, Yoyo*; Hori, Satoshi*; Iwasaki, Rui*; Kanno, Ryoji*; Ohara, Takashi; Nakao, Akiko*; Munakata, Koji*; Hiroi, Zenji*
Journal of Materials Chemistry A, 9(18), p.11278 - 11284, 2021/05
Times Cited Count：11 Percentile：78.4(Chemistry, Physical)
=0 long-range magnetic order in centennialite CaCu
(OD)
Cl 
0.6DO; A Spin-
perfect kagome antiferromagnet with 
-
-
Iida, Kazuki*; Yoshida, Hiroyuki*; Nakao, Akiko*; Jeschke, H. O.*; Iqbal, Y.*; Nakajima, Kenji; Kawamura, Seiko; Munakata, Koji*; Inamura, Yasuhiro; Murai, Naoki; et al.
Physical Review B, 101(22), p.220408_1 - 220408_6, 2020/06
Times Cited Count：18 Percentile：83.65(Materials Science, Multidisciplinary)Crystal and magnetic structures of the mineral centennialite CaCu(OD)Cl 0.6DO are investigated by means of synchrotron X-ray diffraction and neutron diffraction measurements complemented by density functional theory (DFT) and pseudofermion functional renormalization group (PFFRG) calculations. In CaCu(OD)Cl 0.6DO, Cu
ions form a geometrically perfect kagome network with antiferromagnetic . No intersite disorder between Cu and Ca ions is detected. CaCu(OD)Cl 0.6DO enters a magnetic long-range ordered state below 
= 7.2 K, and the =0 magnetic structure with negative vector spin chirality is obtained. The ordered moment at 0.3 K is suppressed to 0.58(2)
B. Our DFT calculations indicate the presence of antiferromagnetic and ferromagnetic superexchange couplings of a strength which places the system at the crossroads of three magnetic orders (at the classical level) and a spin- PFFRG analysis shows a dominance of =0 type magnetic correlations, consistent with and indicating proximity to the observed =0 spin structure. The results suggest that this material is located close to a quantum critical point and is a good realization of a -- kagome antiferromagnet.
Ir
Sn
(
: La and Ce) investigated using neutron and X-ray diffractionNakazato, Seiya*; Iwasa, Kazuaki*; Hashimoto, Daisuke*; Shiozawa, Mami*; Kuwahara, Keitaro*; Nakao, Hironori*; Sagayama, Hajime*; Ishikado, Motoyuki*; Ohara, Takashi; Nakao, Akiko*; et al.
JPS Conference Proceedings (Internet), 30, p.011128_1 - 011128_6, 2020/03
CoFe
O
Komabuchi, Mai*; Urushihara, Daisuke*; Asaka, Toru*; Fukuda, Koichiro*; Ohara, Takashi; Munakata, Koji*; Ishikawa, Yoshihisa*
Journal of the Physical Society of Japan, 89(3), p.034601_1 - 034601_5, 2020/03
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Ikeda, Shugo*; Kaneko, Koji; Tanaka, Yuki*; Kawasaki, Takuro; Hanashima, Takayasu*; Munakata, Koji*; Nakao, Akiko*; Kiyanagi, Ryoji; Ohara, Takashi; Mochizuki, Kensei*; et al.
Journal of the Physical Society of Japan, 89(1), p.014707_1 - 014707_7, 2020/01
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Kaneko, Koji; Frontzek, M. D.*; Matsuda, Masaaki*; Nakao, Akiko*; Munakata, Koji*; Ohara, Takashi; Kakihana, Masashi*; Haga, Yoshinori; Hedo, Masato*; Nakama, Takao*; et al.
Journal of the Physical Society of Japan, 88, p.013702_1 - 013702_5, 2019/01
Times Cited Count：52 Percentile：95.43(Physics, Multidisciplinary)Shamoto, Shinichi; Ito, Takashi; Onishi, Hiroaki; Yamauchi, Hiroki; Inamura, Yasuhiro; Matsuura, Masato*; Akatsu, Mitsuhiro*; Kodama, Katsuaki; Nakao, Akiko*; Moyoshi, Taketo*; et al.
Physical Review B, 97(5), p.054429_1 - 054429_9, 2018/02
Times Cited Count：16 Percentile：66.61(Materials Science, Multidisciplinary)Nuclear and magnetic structure and full magnon dispersions of yttrium iron garnet Y
Fe
O have been studied by neutron scattering. The lowest-energy dispersion below 14 meV exhibits a quadratic dispersion as expected from ferromagnetic magnons. The imaginary part of -integrated dynamical spin susceptibility 
"(
) exhibits a square-root energy-dependence in the low energies. The magnon density of state is estimated from the "() obtained on an absolute scale. The value is consistent with a single chirality mode for the magnon branch expected theoretically.
Kawamura, Seiko; Oku, Takayuki; Watanabe, Masao; Takahashi, Ryuta; Munakata, Koji*; Takata, Shinichi; Sakaguchi, Yoshifumi*; Ishikado, Motoyuki*; Ouchi, Keiichi*; Hattori, Takanori; et al.
Journal of Neutron Research, 19(1-2), p.15 - 22, 2017/11
Sample environment (SE) team at the Materials and Life Science Experimental Facility (MLF) in J-PARC has worked on development and operation of SE equipment and devices. All the members belong to one sub-team at least, such as Cryogenic and magnet, High temperature, High pressure, Soft matter and special environment including Pulse magnet, Hydrogen environment, Light irradiation and 
He spin filter. Cryostats, a magnet, furnaces, a VX-6-type Paris-Edinburgh press and a prototype of a Spin-Exchange Optical Pumping (SEOP) based He spin filter for polarized neutron beam experiments are in operation. Furthermore, a prototype of compact power supply for a pulsed magnet system is currently developed. In the J-PARC Research Building, several pieces of equipment for softmatter research such as a rheometer and a gas and vapor adsorption measurement instrument have been prepared.
studied by single-crystal time-of-flight neutron diffractionKawasaki, Takuro; Kaneko, Koji; Nakamura, Ai*; Aso, Naofumi*; Hedo, Masato*; Nakama, Takao*; Ohara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Tamura, Itaru; et al.
Journal of the Physical Society of Japan, 85(11), p.114711_1 - 114711_5, 2016/11
Times Cited Count：9 Percentile：57.63(Physics, Multidisciplinary)Ohara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Kaneko, Koji; Kawasaki, Takuro; Tamura, Itaru; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Moyoshi, Taketo*; et al.
Journal of Applied Crystallography, 49(1), p.120 - 127, 2016/02
Times Cited Count：44 Percentile：95.71(Chemistry, Multidisciplinary)Ikeda, Yoichi*; Ueta, Daichi*; Yoshizawa, Hideki*; Nakao, Akiko*; Munakata, Koji*; Ohara, Takashi
Journal of the Physical Society of Japan, 84(12), p.123701_1 - 123701_5, 2015/12
Times Cited Count：4 Percentile：36.38(Physics, Multidisciplinary)Single-crystal neutron diffraction study was performed for anomalous antiferromagnetic ordering in a heavy-electron superconductor CeNiGe. We observed incommensurate magnetic Bragg reflections characterized with the propagation vector of 
= (0; 0:41; 1=2) below the N
el temperature of 5 K, while there is no significant magnetic reflection at the commensurate propagation vector of 
= (1; 0; 0) at which another magnetic reflection was observed in the previous neutron diffraction study with a polycrystalline sample. From the single crystal study, we suggest that the magnetic phase of CeNiGe at ambient pressure is characterized only by the incommensurate propagation vector .
Oikawa, Kenichi; Kawasaki, Takuro; Ohara, Takashi; Kiyanagi, Ryoji; Kaneko, Koji; Tamura, Itaru; Nakamura, Tatsuya; Harada, Masahide; Nakao, Akiko*; Hanashima, Takayasu*; et al.
JPS Conference Proceedings (Internet), 1, p.014013_1 - 014013_5, 2014/03
A new single crystal time-of-flight neutron diffractometer has been installed at BL18 of the Materials and Life Science Experimental Facility of J-PARC. The diffractometer "SENJU" was designed for precise crystal and magnetic structure analyses using a small crystal less than 1.0 mm under multiple extreme environments such as low-temperature and high-magnetic field. The first neutron beam was delivered to the sample position on March 5, 2012. Subsequently, the hardware and software of SENJU have been checked and confirmed that they worked fine. At the same time, diffraction experiments of several organic and inorganic crystals have been done using NaCl, C12A7, and so on. In these measurements, Bragg reflections in the high-Q region (d-spacing 
0.5 
) were clearly observed and analyzed successfully. In this presentation, we will show the instrument design and performance evaluation of SENJU in detail.
Kawasaki, Takuro; Kaneko, Koji; Aso, Naofumi*; Nakamura, Ai*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*; Ohara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; et al.
JPS Conference Proceedings (Internet), 1, p.014009_1 - 014009_4, 2014/03
Oikawa, Kenichi; Ohara, Takashi*; Kiyanagi, Ryoji; Kawasaki, Takuro; Tamura, Itaru; Kaneko, Koji; Kimura, Hiroyuki*; Noda, Yukio*; Takahashi, Miwako*; Kiyotani, Tamiko*; et al.
no journal, ,
A new single crystal neutron diffractometer SENJU is now being built at a rapid rate in BL18 of MLF at J-PARC. The instrument realize measurements using small sample, less than 1.0 
under combined special environment at 1 MW beam power. We designed the beamline specification considering sample size and its mosaicity, spacial resolution of the area detector, and so on. The concrete design input and their detailed investigation process of the beamline will be presented.
Kiyanagi, Ryoji; Oikawa, Kenichi; Tamura, Itaru; Ohara, Takashi; Kawasaki, Takuro; Kaneko, Koji; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Kimura, Hiroyuki*; et al.
no journal, ,
Oikawa, Kenichi; Ohara, Takashi*; Kiyanagi, Ryoji; Kawasaki, Takuro; Tamura, Itaru; Kaneko, Koji; Nakamura, Tatsuya; Sakasai, Kaoru; Nakao, Akiko*; Hanashima, Takayasu*; et al.
no journal, ,
SENJU, named after the thousand armed Goddess of Mercy, is a single crystal time-of-flight Laue diffractometer proposed to the MLF at J-PARC. The diffractometer is dedicated for precise crystal and magnetic structure analyses under the combined extreme conditions using a small sample less than 1 . TOF-Laue technique coupled with wide area 2D detectors enables the efficient measurements and improves the completeness of the data. A WLSF-type scintillator detector developed for iBIX was modified to meet the requirements of SENJU. Although the construction schedule has been delayed because of the earthquake, on-beam commissioning will start in 2012.
Kawamura, Seiko; Yokoo, Tetsuya*; Kambara, Wataru; Munakata, Koji*; Kajimoto, Ryoichi*; Nakatani, Takeshi; Kaneko, Koji; Kawakita, Yukinobu; Takata, Shinichi; Nakajima, Kenji; et al.
no journal, ,
In large user facilities such as neutron experimental facilities, sample environment (SE) is one of the most important factors to yield high-quality output. In the Materials and Life Science Experimental Facility (MLF) in J-PARC, various neutron experiments have been performed in wide range of scientific researches and industrial applications, and the number and variety of proposals will further increase after resuming operation of J-PARC. At the beginning stage, the SE team in MLF has discussed SE standardization, to save the cost and manpower, to make compatibility among instruments, and to increase the experimental efficiency by sharing the SE devices and techniques for operation. Recently we started preparation of "SE area" in the experimental hall, where we can do maintenance of equipments, pre-cooling of cryostats and so on. The SE team is now discussing future plan including user support system.
Kawasaki, Takuro; Nakamura, Tatsuya; Sakasai, Kaoru; To, Kentaro; Hosoya, Takaaki*; Soyama, Kazuhiko; Katagiri, Masaki*; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; et al.
no journal, ,
