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Kajimoto, Ryoichi; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Inamura, Yasuhiro; Iida, Kazuki*; Ikeuchi, Kazuhiko*; Ishikado, Motoyuki*
EPJ Web of Conferences, 272, p.02007_1 - 02007_8, 2022/11
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Iida, Kazuki*; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Inamura, Yasuhiro; Ishikado, Motoyuki*
Journal of Neutron Research, 22(2-3), p.99 - 107, 2020/10
Yamauchi, Hiroki; Sari, D. P.*; Watanabe, Isao*; Yasui, Yukio*; Chang, L.-J.*; Kondo, Keietsu; Ito, Takashi; Ishikado, Motoyuki*; Hagihara, Masato*; Frontzek, M. D.*; et al.
Communications Materials (Internet), 1, p.43_1 - 43_6, 2020/07
High-temperature short-range order is discovered up to 720 K in MnRhSi by complementary use of neutron scattering and muon spin relaxation measurements.
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
0.6D
O 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
0.6D
O, Cu
ions form a geometrically perfect kagome network with antiferromagnetic
. No intersite disorder between Cu
and Ca
ions is detected. CaCu
(OD)
Cl
0.6D
O 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.
Iida, Kazuki*; Kofu, Maiko; Suzuki, Katsuhiro*; Murai, Naoki; Kawamura, Seiko; Kajimoto, Ryoichi; Inamura, Yasuhiro; Ishikado, Motoyuki*; Hasegawa, Shunsuke*; Masuda, Takatsugu*; et al.
Journal of the Physical Society of Japan, 89(5), p.053702_1 - 053702_5, 2020/05
Times Cited Count:15 Percentile:81.95(Physics, Multidisciplinary)Nakazato, 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
Kajimoto, Ryoichi; Nakajima, Kenji; Fujita, Masaki*; Ishikado, Motoyuki*; Torii, Shuki*; Ishikawa, Yoshihisa*; Miao, P.*; Kamiyama, Takashi*
Journal of the Physical Society of Japan, 88(11), p.114602_1 - 114602_6, 2019/11
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Ishikado, Motoyuki*; Kodama, Katsuaki; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Ikeuchi, Kazuhiko*; Ji, S.*; Arai, Masatoshi*; Shamoto, Shinichi
Condensed Matter (Internet), 4(3), p.69_1 - 69_10, 2019/09
The enhancement magnetic resonance mode of FeTeSe
is limited around Q = (
, 0). Q dependence is found to be consistent with a theoretical simulation of the magnetic resonance mode with the sign-reversing order parameter of s
wave.
Kawamura, Seiko; Takahashi, Ryuta*; Ishikado, Motoyuki*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ouchi, Keiichi*; Kira, Hiroshi*; Kambara, Wataru*; Aoyama, Kazuhiro*; Sakaguchi, Yoshifumi*; et al.
Journal of Neutron Research, 21(1-2), p.17 - 22, 2019/05
The Cryogenics and Magnets group in the Sample Environment team is responsible for operation of cryostats and magnets for user's experiments at the MLF in J-PARC. We have introduced a top-loading He cryostat, a bottom-loading
He cryostat, a dilution refrigerator insert and a superconducting magnet. The frequency of use of them dramatically becomes higher in these two years, as the beam power and the number of proposal increase. To respond such situation, we have made efforts to enhance performance of these equipment as follows. The
He cryostat originally involves an operation software for automatic initial cooling down to the base temperature and automatic re-charge of
He. Recently we made an additional program for automatic temperature control with only the sorb heater. Last year, a new outer vacuum chamber of the magnet with an oscillating radial collimator (ORC) was fabricated. The data quality was drastically improved by introducing this ORC so that the magnet can be used even for the inelastic neutron scattering experiments.
Kajimoto, Ryoichi; Ishikado, Motoyuki*; Kira, Hiroshi*; Kaneko, Koji; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Inamura, Yasuhiro; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Murai, Naoki; et al.
Physica B; Condensed Matter, 556, p.26 - 30, 2019/03
Times Cited Count:2 Percentile:12.96(Physics, Condensed Matter)Iida, Kazuki*; Yoshida, Hiroyuki*; Okabe, Hirotaka*; Katayama, Naoyuki*; Ishii, Yuto*; Koda, Akihiro*; Inamura, Yasuhiro; Murai, Naoki; Ishikado, Motoyuki*; Kadono, Ryosuke*; et al.
Scientific Reports (Internet), 9(1), p.1826_1 - 1826_9, 2019/02
Times Cited Count:6 Percentile:53.31(Multidisciplinary Sciences)Nakamura, Mitsutaka; Kambara, Wataru*; Iida, Kazuki*; Kajimoto, Ryoichi; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Ishikado, Motoyuki*; Aoyama, Kazuhiro*
Physica B; Condensed Matter, 551, p.480 - 483, 2018/12
Times Cited Count:3 Percentile:17.91(Physics, Condensed Matter)Recently there has been an increasing need for inelastic neutron scattering experiments under some special environments such as magnetic fields, pressure and high temperatures. In order to obtain high quality data, the unnecessary scattering caused by sample environmental apparatus should be suppressed as much as possible. We have developed an oscillating radial collimator with a view to satisfying users' needs, which is specialized for the Fermi chopper spectrometer 4SEASONS at J-PARC.4SEASONS provides relatively high incident energies, and thus we chose hydrogen free metal sheets as the collimator blades. The control system of this oscillating radial collimator enables us to flexibly tune the oscillating pattern, such as the oscillating speed and oscillating angle. In this presentation, we report the performances and remaining issues of the newly developed oscillating radial collimator for 4SEASONS.
Ishikado, Motoyuki*; Shamoto, Shinichi; Kodama, Katsuaki; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Hong, T.*; Mutka, H.*
Scientific Reports (Internet), 8, p.16343_1 - 16343_6, 2018/11
Times Cited Count:2 Percentile:23.34(Multidisciplinary Sciences)Spin fluctuations are widely believed to play an important role as one of the most possible mechanisms for unconventional high-temperature superconductors. Here, the spin fluctuation in LaFePO is found at high energies such as 30-50 meV with comparable intensity to an optimally doped LaFeAs(O,F).
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Murai, Naoki; Kira, Hiroshi*; Nakatani, Takeshi; et al.
Journal of Physics; Conference Series, 1021(1), p.012030_1 - 012030_6, 2018/06
Times Cited Count:3 Percentile:90.78Kawamura, 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.
Iida, Kazuki*; Ishikado, Motoyuki*; Nagai, Yuki; Yoshida, Hiroyuki*; Christianson, A. D.*; Murai, Naoki; Kawashima, Kenji*; Yoshida, Yoshiyuki*; Eisaki, Hiroshi*; Iyo, Akira*
Journal of the Physical Society of Japan, 86(9), p.093703_1 - 093703_4, 2017/09
Times Cited Count:23 Percentile:81.4(Physics, Multidisciplinary)Kamazawa, Kazuya*; Ishikado, Motoyuki*; Kawamura, Seiko; Kawakita, Yukinobu; Kakurai, Kazuhisa*; Nakajima, Kenji; Sato, Masashi*
Physical Review B, 95(10), p.104413_1 - 104413_7, 2017/03
Times Cited Count:2 Percentile:12.75(Materials Science, Multidisciplinary)Nomura, Takuji*; Harada, Yoshihisa*; Niwa, Hideharu*; Ishii, Kenji*; Ishikado, Motoyuki*; Shamoto, Shinichi; Jarrige, I.*
Physical Review B, 94(3), p.035134_1 - 035134_9, 2016/07
Times Cited Count:10 Percentile:46.96(Materials Science, Multidisciplinary)Low-energy electron excitation spectra were measured on a single crystal of a typical iron-based superconductor PrFeAsO using resonant inelastic X-ray scattering (RIXS) at the Fe-
edge.
Nakamura, Mitsutaka; Ikeuchi, Kazuhiko*; Kajimoto, Ryoichi; Kambara, Wataru; Krist, T.*; Shinohara, Takenao; Arai, Masatoshi; Iida, Kazuki*; Kamazawa, Kazuya*; Inamura, Yasuhiro; et al.
JAEA-Conf 2015-002, p.339 - 348, 2016/02
We have developed a new Fermi chopper referred to as Magic chopper to realize the full optimization of the experimental condition for Multi-Ei method in a chopper spectrometer. In this study, the theoretical aspects of MAGIC chopper concept will be initially presented, and the performances of MAGIC chopper will be evaluated by both Monte Carlo simulation and neutron transmission experiment.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Nakajima, Kenji; Kawamura, Seiko; Nakatani, Takeshi; et al.
JAEA-Conf 2015-002, p.319 - 329, 2016/02