Yang, J.*; Ren, W.*; Zhao, X.*; Kikuchi, Tatsuya*; Miao, P.*; Nakajima, Kenji; Li, B.*; Zhang, Z.*
Journal of Materials Science and Technology, 99, p.55 - 60, 2022/02
High-entropy alloys are characteristic of extensive atomic occupational disorder on high-symmetric lattices, differing from traditional alloys. Here, we investigate magnetic and thermal transport properties of the prototype face-centered-cubic high-entropy alloy CrMnFeCoNi by combining physical properties measurements and neutron scattering. Direct-current (dc) and alternating-current (ac) magnetizations measurements indicate a mictomagnetic behavior with coexisting antiferromagnetic and ferromagnetic interactions in the entire temperature region and three anomalies are found at about 80, 50, and 20 K, which are related to the paramagnetic to antiferromagnetic transition, the antiferromagnetic to ferromagnetic transition, and the spin freezing, respectively. The electrical and thermal conductivities are significantly reduced compared to Ni and the temperature dependence of lattice thermal conductivity exhibits a glass-like plateau. Inelastic neutron scattering measurements suggest weak anharmonicity so that the thermal transport is expected to be dominated by the defect scattering.
Klotz, S.*; Baptiste, B.*; Hattori, Takanori; Feng, S. M.*; Jin, Ch.*; Bneut, K.*; Guigner, J. M.*; Estve, I.*
Carbon, 185, p.491 - 500, 2021/11
Carbon disulphide (CS) is one of the simplest molecular systems made of double covalent bonds. Under high pressure, the molecular structure is expected to break up to form extended crystalline or polymeric solids. Here we show that by compression at 300 K to approximately 10 GPa using large-volume high pressure techniques, an instantaneous reaction leads to a mixture of pure sulphur and a well-defined compound with stoichiometry close to CS which can be recovered to ambient pressure. We present neutron and X-ray diffraction as well as Raman data which show that this material consists of sulphur bonded to sp graphite layers of nanometric dimensions. The compound is a semiconductor with a gap of 45 meV, as revealed by temperature dependent resistivity measurements, and annealing at temperatures above 200C allow to reduce its sulphur content up to CS. Its structural and electronic properties are fundamentally different to "Bridgman black" reported from previous high pressure experiments on CS.
Yoneda, Yasuhiro; Noguchi, Yuji*
Japanese Journal of Applied Physics, 60(SF), p.SFFA08_1 - SFFA08_10, 2021/11
BiNaTiO (abbreviated as BNT) is a lead-free material but exhibits relatively large piezoelectric properties, a lot of researches have been conducted. We performed local structural analysis using high-quality BNT with a stoichiometrically correct composition, and found a chemical order structure of Bi/Na in locally. BNT undergoes a phase transition to a cubic phase at 400C. We estimated that a new disorder structure will appear in the high-temperature phase. In the high temperature phase, pair distribution function (PDF) analysis using synchrotron radiation high-energy X-rays was performed. As a result, we found that Bi shifts from 200C, and this shift becomes an order parameter for the phase transition.
Hashimoto, Shunsuke*; Nakajima, Kenji; Kikuchi, Tatsuya*; Kamazawa, Kazuya*; Shibata, Kaoru; Yamada, Takeshi*
Journal of Molecular Liquids, 342, p.117580_1 - 117580_8, 2021/11
Quasi-elastic neutron scattering (QENS) and pulsed-field-gradient nuclear magnetic resonance (PFGNMR) analyses of a nanofluid composed of silicon dioxide (SiO) nanoparticles and a base fluid of ethylene glycol aqueous solution were performed. The aim was to elucidate the mechanism increase in the thermal conductivity of the nanofluid above its theoretical value. The obtained experimental results indicate that SiO particles may decrease the self-diffusion coefficient of the liquid molecules in the ethylene glycol aqueous solution because of their highly restricted motion around these nanoparticles. At a constant temperature, the thermal conductivity increases as the self-diffusion coefficient of the liquid molecules decreases in the SiO nanofluids.
Ito, Kanae; Yamada, Takeshi*; Shinohara, Akihiro*; Takata, Shinichi; Kawakita, Yukinobu
Journal of Physical Chemistry C, 125(39), p.21645 - 21652, 2021/10
Journal of the Physical Society of Japan, 90(10), p.104701_1 - 104701_5, 2021/10
Im, S.*; Jee, H.*; Suh, H.*; Kanematsu, Manabu*; Morooka, Satoshi; Koyama, Taku*; Nishio, Yuhei*; Machida, Akihiko*; Kim, J.*; Bae, S.*
Journal of the American Ceramic Society, 104(9), p.4803 - 4818, 2021/09
Kensa Gijutsu, 26(9), p.9 - 13, 2021/09
no abstracts in English
Tremsin, A. S.*; Bilheux, H. Z.*; Bilheux, J. C.*; Shinohara, Takenao; Oikawa, Kenichi; Gao, Y.*
Nuclear Instruments and Methods in Physics Research A, 1009, p.165493_1 - 165493_12, 2021/09
Gao, D.*; Tang, X.*; Wang, X.*; Yang, X.*; Zhang, P.*; Che, G.*; Han, J.*; Hattori, Takanori; Wang, Y.*; Dong, X.*; et al.
Physical Chemistry Chemical Physics, 23(35), p.19503 - 19510, 2021/09
Pressure-induced phase transition and polymerization of nitrogen-rich molecules are widely focused due to its extreme importance for the development of green high energy density materials. Here, we present a study of the phase transition and chemical reaction of 1H-tetrazole up to 100 GPa by using Raman, IR, X-ray diffraction, neutron diffraction techniques and theoretical calculation. A phase transition above 2.6 GPa was identified and the high-pressure structure was determined with one molecule in a unit cell. The 1H-tetrazole polymerizes reversibly below 100 GPa, probably through a carbon-nitrogen bonding instead of nitrogen-nitrogen bonding. Our studies updated the structure model of the high pressure phase of 1H-tetrazole, and presented the possible intermolecular bonding route for the first time, which gives new insights to understand the phase transition and chemical reaction of nitrogen-rich compounds, and benefit for designing new high energy density materials.
Knafo, W.*; Knebel, G.*; Steffens, P.*; Kaneko, Koji; Rosuel, A.*; Brison, J.-P.*; Flouquet, J.*; Aoki, Dai*; Lapertot, G.*; Raymond, S.*
Physical Review B, 104(10), p.L100409_1 - L100409_6, 2021/09
Matsuura, Masato*; Fujiwara, Yasuyuki*; Moriwake, Hiroki*; Ohara, Koji*; Kawakita, Yukinobu
Physical Review B, 104(9), p.094305_1 - 094305_7, 2021/09
Fujiwara, Hidenori*; Umetsu, Rie*; Kuroda, Fumiaki*; Miyawaki, Jun*; Kashiuchi, Toshiyuki*; Nishimoto, Kohei*; Nagai, Kodai*; Sekiyama, Akira*; Irizawa, Akinori*; Takeda, Yukiharu; et al.
Scientific Reports (Internet), 11(1), p.18654_1 - 18654_9, 2021/09
Shibata, Takanori*; Shinto, Katsuhiro; Wada, Motoi*; Oguri, Hidetomo; Ikegami, Kiyoshi*; Okoshi, Kiyonori; Nammo, Kesao*
AIP Conference Proceedings 2373, p.050002_1 - 050002_9, 2021/08
Oscillation of emittance and Twiss parameters in the negative ion beam from the J-PARC 2-MHz RF ion source is measured by applications of a double-slit emittance monitor located at the RFQ (Radio Frequency Quadrupole) entrance. The emittance monitor is equipped with a newly-developed 60 MS/s data acquisition system, so that beam current oscillation in a few MHz can be observed with enough time resolution. From the measurement, it is shown that the beam phase space consists of (1) a DC component in the beam core, (2) a 2-MHz oscillating component which takes place both in the beam core and the halo and (3) a doubled RF frequency (4 MHz) oscillation which slightly exists in the beam halo. The major component is the 2-MHz component, which resultantly decides the beam emittance oscillation frequency. A typical value of the beam emittance in the present experiment is 0.34 mm-mrad, while the amplitude of the 2 MHz oscillation is around 0.04 mm-mrad. The results indicate that the high-frequency oscillation component occupying about ten-percent of the beam from the RF source travels a few meters passing through a magnetic lens focusing system.
Sarmento, T.*; Wnderlich, D.*; Fantz, U.*; Friedl, R.*; Rauner, D.*; Tsumori, Katsuyoshi*; Shenjin, L.*; Chen, W.*; Bollinger, D.*; Oguri, Hidetomo; et al.
AIP Conference Proceedings 2373, p.110001_1 - 110001_18, 2021/08
In preparation for NIBS 2020 various labs prepared reference sheets containing key information about their ion sources and the machines that they serve. The contents of the reference sheets have been formatted and edited into this paper for posterity and ease of access.
Nakagawa, Hiroshi; Saio, Tomohide*; Nagao, Michihiro*; Inoue, Rintaro*; Sugiyama, Masaaki*; Ajito, Satoshi; Tominaga, Taiki*; Kawakita, Yukinobu
Biophysical Journal, 120(16), p.3341 - 3354, 2021/08
A multi-domain protein can have various conformations in solution. Interactions with other molecules result in the stabilization of one of the conformations and change in the domain dynamics. SAXS, a well-established experimental technique, can be employed to elucidate the conformation of a multi-domain protein in solution. NSE spectroscopy is a promising technique for recording the domain dynamics in nanosecond and nanometer scale. Despite the great efforts, there are still under development. Thus, we quantitatively removed the contribution of diffusion dynamics and hydrodynamic interactions from the NSE data via incoherent scattering, revealing the differences in the domain dynamics of the three functional states of a multi-domain protein, MurD. The differences among the three states can be explained by two domain modes.
Saio, Tomohide*; Hiramatsu, Soya*; Asada, Mizue*; Nakagawa, Hiroshi; Shimizu, Kazumi*; Kumeta, Hiroyuki*; Nakamura, Toshikazu*; Ishimori, Koichiro*
Biophysical Journal, 120(15), p.2943 - 2951, 2021/08
A rigid double-arm lanthanide tag was utilized in electron paramagnetic resonance spectroscopy to measure the distance between two specific points on a protein, and conformational states and distribution of a multi-domain protein enzyme MurD was investigated. Although the previous crystallographic and NMR studies have reported the three distinct conformational states of MurD, our data unveiled that the protein exists in much more variety of conformational states in the absence of the ligand. Given the fact that MurD is one of the potent drug target for infectious diseases, the finding in this study will provide important structural basis for drug development.
Tamura, Fumihiko; Takahashi, Hiroki; Kamikubota, Norihiko*; Ito, Yuichi*; Hayashi, Naoki
IEEE Transactions on Nuclear Science, 68(8), p.2043 - 2050, 2021/08
A precise and stable timing system is necessary for high intensity proton accelerators such as the J-PARC. The existing timing system, which was developed during the construction period of the-PARC, has been working without major issues since 2006. After a decade of operation, the optical modules, which are key components for signal transfer, were discontinued already. Thus, the next-generation timing system for the J-PARC is under development. The new system is designed to be compatible with the existing system in terms of the operating principle. The new system utilizes modern high speed signal communication for the transfer of the clock, trigger, and type code. We present the system configuration of the next-generation timing system and current status.
Adachi, Nozomu*; Ueno, Haruki*; Onoe, Katsuhiko*; Morooka, Satoshi; Todaka, Yoshikazu*
ISIJ International, 61(8), p.2320 - 2322, 2021/08
Miyazaki, Tsukasa*; Miyata, Noboru*; Arima, Hiroshi*; Kira, Hiroshi*; Ouchi, Keiichi*; Kasai, Satoshi*; Tsumura, Yoshihiro*; Aoki, Hiroyuki
Langmuir, 37(32), p.9873 - 9882, 2021/08