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Journal Articles

Layered structure in the crystalline adsorption layer and the leaching process of poly(vinyl alcohol) revealed by neutron reflectivity

Miyazaki, Tsukasa*; Miyata, Noboru*; Arima, Hiroshi*; Kira, Hiroshi*; Ouchi, Keiichi*; Kasai, Satoshi*; Tsumura, Yoshihiro*; Aoki, Hiroyuki

Langmuir, 37(32), p.9873 - 9882, 2021/08

 Times Cited Count:0 Percentile:0(Chemistry, Multidisciplinary)

Journal Articles

Detailed structural study on the poly(vinyl alcohol) adsorption layers on a Si substrate with solvent vapor-induced swelling

Miyazaki, Tsukasa*; Miyata, Noboru*; Yoshida, Tessei*; Arima, Hiroshi*; Tsumura, Yoshihiro*; Torikai, Naoya*; Aoki, Hiroyuki; Yamamoto, Katsuhiro*; Kanaya, Toshiji*; Kawaguchi, Daisuke*; et al.

Langmuir, 36(13), p.3415 - 3424, 2020/04

 Times Cited Count:6 Percentile:75.63(Chemistry, Multidisciplinary)

Journal Articles

Development of a technique for high pressure neutron diffraction at 40 GPa with a Paris-Edinburgh press

Hattori, Takanori; Sano, Asami; Machida, Shinichi*; Abe, Jun*; Funakoshi, Kenichi*; Arima, Hiroshi*; Okazaki, Nobuo*

High Pressure Research, 39(3), p.417 - 425, 2019/06

AA2019-0119.pdf:1.79MB

 Times Cited Count:9 Percentile:77.94(Physics, Multidisciplinary)

We have developed a technique for neutron diffraction experiments at pressures up to 40 GPa using a Paris-Edinburgh press at the PLANET beamline in J-PARC. To increase the maximum accessible pressure, the diameter of the dimple for sample chamber at the top of the sintered diamond anvils is sequentially reduced from 4.0 mm to 1.0 mm. As a result, the maximum pressure increased and finally reached 40 GPa. By combining this technique with the beam optics which defines the gauge volume, diffraction patterns sufficient for full-structure refinements are obtainable at such pressures.

Journal Articles

Molecular dynamics simulations of physical properties of water and cations in montmorillonite interlayer; Application to diffusion model

Yotsuji, Kenji*; Tachi, Yukio; Kawamura, Katsuyuki*; Arima, Tatsumi*; Sakuma, Hiroshi*

Nendo Kagaku, 58(1), p.8 - 25, 2019/00

Molecular dynamics (MD) simulations were conducted to investigate physical properties of water and cations in montmorillonite interlayer nanopores. The swelling behaviors and hydration states were firstly evaluated as functions of interlayer cations and layer charge. The diffusion coefficients of water and cations in interlayer nanopores were decreased in comparison with those in bulk water and came closer to those in bulk water when basal spacing increased. The viscosity coefficients of interlayer water estimated indicated a significant effect of viscoelectricity at 1- and 2-layer hydration states and higher layer charge of montmorillonite. These trends from MD calculations were confirmed to be consistent with existing measured data and previous MD simulation. In addition, model and parameter related to viscoelectric effect used in the diffusion model was refined based on comparative discussion between MD simulations and measurements. The series of MD calculations could provide atomic level understanding for the developments and improvements of the diffusion model for compacted montmorillonite.

Journal Articles

Phase-transition kinetics of magnetic skyrmions investigated by stroboscopic small-angle neutron scattering

Nakajima, Taro*; Inamura, Yasuhiro; Ito, Takayoshi*; Oishi, Kazuki*; Oike, Hiroshi*; Kagawa, Fumitaka*; Kikkawa, Akiko*; Taguchi, Yasujiro*; Kakurai, Kazuhisa*; Tokura, Yoshinori*; et al.

Physical Review B, 98(1), p.014424_1 - 014424_5, 2018/07

 Times Cited Count:4 Percentile:32.53(Materials Science, Multidisciplinary)

We investigated the phase-transition kinetics of magnetic skyrmion lattice (SkL) in MnSi by means of stroboscopic small-angle neutron scattering (SANS). Temporal evolutions of SANS patterns were measured with time resolution of 13 ms while sweeping temperature as fast as 50 Ks$$^{-1}$$. It turned out that the paramagnetic-to-SkL transition immediately occurs upon traversing the equilibrium phase boundary on the rapid cooling, whereas the SkL-to-conical transition can be kinetically avoided to realize the low-temperature metastable SkL with a long-range magnetic order. The formation of the metastable SkL was found to be strongly dependent not only on cooling rate, but also on magnetic eld and trajectory in the H-T phase diagram.

Journal Articles

Stability of montmorillonite edge faces studied using first-principles calculations

Sakuma, Hiroshi*; Tachi, Yukio; Yotsuji, Kenji; Suehara, Shigeru*; Arima, Tatsumi*; Fujii, Naoki*; Kawamura, Katsuyuki*; Honda, Akira

Clays and Clay Minerals, 65(4), p.252 - 272, 2017/08

 Times Cited Count:1 Percentile:15.06(Chemistry, Physical)

Structure and stability of montmorillonite edge faces (110), (010), (100), and (130) of the layer charges y = 0.5 and 0.33 are investigated by the first-principles electronic calculations based on the density functional theory. Stacking and single layer models are tested for understanding the effect of stacking on the stability of montmorillonite edge faces. Most stacking layers stabilize the edge faces by making hydrogen bonds between the layers; therefore, the surface energy of stacking layers is reduced rather than the single layer model. This indicates that the surface energy of edge faces should be estimated depending on the swelling conditions. Lowest surface energies of (010) and (130) edge faces were realized by the presence of Mg ions on the edge faces. These edge faces have a strong adsorption site for cations due to local negative charge of the edges.

Journal Articles

Overview of high-pressure neutron beamline, PLANET, and practical aspects of the experiments

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Funakoshi, Kenichi*; Abe, Jun*; Machida, Shinichi*; Okazaki, Nobuo*; Ouchi, Keiichi*; Inamura, Yasuhiro

Koatsuryoku No Kagaku To Gijutsu, 26(2), p.89 - 98, 2016/06

PLANET is a high-pressure neutron beamline constructed at pulsed-neutron source in Materials and Life Science Facility (MLF) in J-PARC. The six-axis multi-anvil press designed for time of flight (TOF) neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators that eliminate parasitic scattering from the high-pressure cell. The high performance of the diffractometer for the resolution ($$Delta d/d$$ $$sim$$ 0.6%) and the accessible d-spacing range (0.2 - 8.4 ${AA}$) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.

Journal Articles

How had the high-pressure neutron diffractometer PLANET been constructed?

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*

Hamon, 26(2), p.85 - 90, 2016/05

PLANET is the first neutron powder diffractometer dedicated to high-pressure and high-temperature experiments in the World. The six-axis press designed for this beamline enables routine data collection at pressures and temperatures up to 10 GPa and 2000K. In this article, we introduce how the PLANET had been constructed.

Journal Articles

Design and performance of high-pressure PLANET beamline at pulsed neutron source at J-PARC

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Komatsu, Kazuki*; Yamada, Akihiro*; Inamura, Yasuhiro; Nakatani, Takeshi; Seto, Yusuke*; Nagai, Takaya*; Utsumi, Wataru; et al.

Nuclear Instruments and Methods in Physics Research A, 780, p.55 - 67, 2015/04

 Times Cited Count:52 Percentile:98.93(Instruments & Instrumentation)

PLANET is a time-of-flight (ToF) neutron beamline dedicated to high-pressure and high-temperature experiments. The large six-axis multi-anvil high-pressure press designed for ToF neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators to eliminate parasitic scattering from the high-pressure cell assembly. The high performance of the diffractometer for the resolution ($$Delta$$ $$d$$/$$d$$ $$sim$$ 0.6%) and the accessible $$d$$-spacing range (0.2-8.4 ${AA}$) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.

Journal Articles

Six-axis multi-anvil press for high-pressure, high-temperature neutron diffraction experiments

Sano, Asami; Hattori, Takanori; Arima, Hiroshi*; Yamada, Akihiro*; Tabata, Satoshi*; Kondo, Masahiro*; Nakamura, Akihiro*; Kagi, Hiroyuki*; Yagi, Takehiko*

Review of Scientific Instruments, 85(11), p.113905_1 - 113905_8, 2014/11

 Times Cited Count:30 Percentile:81.89(Instruments & Instrumentation)

We developed a six-axis multi-anvil press, ATSUHIME, for high-pressure and high-temperature in situ time-of-flight neutron powder diffraction experiments. The press has six orthogonally oriented hydraulic rams that operate individually to compress a cubic sample assembly. Experiments indicate that the press can generate pressures up to 9.3 GPa and temperatures up to 2000 K using a 6-6-type cell assembly, with available sample volume of about 50 mm $$^{3}$$. Using a 6-8-type cell assembly, the available conditions expand to 16 GPa and 1273 K. Combination of the six-axis press and the collimation devices realized high-quality diffraction pattern with no contamination from the heater or the sample container surrounding the sample. This press constitutes a new tool for using neutron diffraction to study the structures of crystals and liquids under high pressures and temperatures.

Journal Articles

High-quality single crystal growth and unique electronic states under magnetic field and pressure in rare earth and actinide compounds

Onuki, Yoshichika; Settai, Rikio*; Takeuchi, Tetsuya*; Sugiyama, Kiyohiro*; Honda, Fuminori*; Haga, Yoshinori; Yamamoto, Etsuji; Matsuda, Tatsuma; Tateiwa, Naoyuki; Aoki, Dai*; et al.

Journal of the Physical Society of Japan, 81(Suppl.B), p.SB001_1 - SB001_18, 2012/12

Journal Articles

Formation of NaCl-type monodeuteride LaD by the disproportionation reaction of LaD$$_{2}$$

Machida, Akihiko; Honda, Mitsunori*; Hattori, Takanori; Sano, Asami; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi; Komatsu, Kazuki*; Arima, Hiroshi*; Oshita, Hidetoshi*; et al.

Physical Review Letters, 108(20), p.205501_1 - 205501_5, 2012/05

 Times Cited Count:10 Percentile:58.4(Physics, Multidisciplinary)

Hydrogen atoms absorbed in a metal occupy the interstitial sites of the metal lattice. In an fcc metal lattice, each metal atom has two tetrahedral (T) and one octahedral (O) sites that can accommodate hydrogen. Rare-earth metal La forms T-site occupied LaH$$_2$$ and fully occupied LaH$$_3$$. O-site occupied or NaCl-type monohydride has yet to be reported for rare-earth metals. Previous X-ray diffraction measurements revealed the pressure-induced decomposition of an fcc-LaH$$_{2.3}$$ into H-rich and H-poor phases around 11 GPa. The present neutron diffraction measurements on LaD$$_{2}$$ confirm the formation of NaCl-type LaD as a counterpart of the D-rich LaD$$_{2+delta}$$ by disproportionation. First-principle calculations demonstrate that the NaCl-type LaH is stabilized at high pressures. Finding the NaCl-type LaH will pave the way for investigations on the site-dependent nature of hydrogen-metal interactions.

Journal Articles

Precise structural analyses of advanced materials under high-pressure and high-temperature

Yoshiasa, Akira*; Murai, Keiichiro*; Arima, Hiroshi*; Katayama, Yoshinori

International Journal of Modern Physics B, 25(31), p.4159 - 4162, 2011/12

 Times Cited Count:0 Percentile:0.01(Physics, Applied)

Precise structure analyses of advanced materials under pressure were performed using each advantage of X-ray absorption fine structure (XAFS) and diffraction methods. Measurements were performed in-situ under pressure and temperature using a large-volume multi-anvil pressure apparatus and synchrotron radiation. XAFS spectra are useful for phase study under high temperature and high pressure. The XAFS Debye-Waller factor provides anharmonic effective pair potential with a pressure-dependent and temperature-independent shape. The phonon energies and anharmonicity are affected largely by the change in local structure and bonding character.

JAEA Reports

Proceedings of the Workshops on "JAEA Project Researches at J-PARC/MLF"; Sep.29, Oct.28, and Oct.29, 2010, Ibaraki Quantum Beam Research Center, Tokai, Ibaraki, Japan

Kajimoto, Ryoichi; Maekawa, Fujio; Arima, Hiroshi; Yoshinari, Shizuka*; Arai, Masatoshi

JAEA-Review 2011-014, 213 Pages, 2011/06

JAEA-Review-2011-014.pdf:38.19MB

The operation for public use of MLF at J-PARC has started since the end of 2008. Rather stable neutron and muon beams at 120 kW are being supplied throughout 2010. Some of the instruments have already produced several good scientific outputs. Furthermore, operation at 200 kW, which exceeds the beam power of the ISIS facility in UK, has started since December 2010. In this promising situation for MLF, we hold three workshops for five neutron instruments which conducted researches for projects by Japan Atomic Energy Agency (JAEA) (project researches): "Workshop on BL19 (Sep. 29)", "Workshop on BL04+BL10 (Oct. 28)", and "Workshop on BL01+BL14 (Oct. 29)". There, status of the instruments and recent results of the project researches as well as a part of researches by general users were reported, and future directions and issues to be solved of the researches were discussed. This report includes abstracts, materials of the presentations and summary of discussions in the workshops.

Journal Articles

Stress/strain effects on industrial superconducting composites

Ito, Takayoshi; Harjo, S.; Osamura, Kozo*; Hemmi, Tsutomu; Awaji, Satoshi*; Machiya, Shutaro*; Oguro, Hidetoshi*; Nishijima, Gen*; Takahashi, Koki*; Matsui, Kunihiro; et al.

Materials Science Forum, 681, p.209 - 214, 2011/05

 Times Cited Count:1 Percentile:58.22

Journal Articles

Aspire to become TAKUMI; TAKUMI present status and research topics

Harjo, S.; Aizawa, Kazuya; Ito, Takayoshi; Arima, Hiroshi; Abe, Jun; Moriai, Atsushi; Sakasai, Kaoru; Nakamura, Tatsuya; Nakatani, Takeshi; Iwahashi, Takaaki; et al.

Materials Science Forum, 652, p.99 - 104, 2010/09

 Times Cited Count:20 Percentile:99.49

The construction of The Engineering Materials Diffractometer, TAKUMI of J-PARC has been finished on March 2009, and the commissioning has been started from September 2008 being parallel with the final stage of the construction. In the commissioning, after checking the validity and the stability of the detectors and the data acquisition system, we checked powder diffraction data of a 2 mm diameter of annealed piano wire with combination of beam collimation (high resolution mode), and confirmed that resolution $$Delta$$$$d$$/$$d$$ of less than 0.2% can be achieved. We also reports preliminary results from researches using TAKUMI.

Journal Articles

Heavy fermion state and quantum criticality

Onuki, Yoshichika; Settai, Rikio*; Honda, Fuminori*; Dung, N. D.*; Ishikura, Tatsuro*; Takeuchi, Tetsuya*; Matsuda, Tatsuma; Tateiwa, Naoyuki; Nakamura, Akio; Yamamoto, Etsuji; et al.

Physica B; Condensed Matter, 405(9), p.2194 - 2199, 2010/05

 Times Cited Count:1 Percentile:7.06(Physics, Condensed Matter)

Journal Articles

A Cubic-anvil high-pressure device for pulsed neutron powder diffraction

Abe, Jun; Arakawa, Masashi*; Hattori, Takanori; Arima, Hiroshi; Kagi, Hiroyuki; Komatsu, Kazuki*; Sano, Asami; Uwatoko, Yoshiya*; Matsubayashi, Kazuyuki*; Harjo, S.; et al.

Review of Scientific Instruments, 81(4), p.043910_1 - 043910_5, 2010/04

 Times Cited Count:6 Percentile:33.58(Instruments & Instrumentation)

A compact cubic-anvil high-pressure device was developed for in situ neutron powder diffraction studies. In this device, a cubic shaped pressure medium is compressed by six anvils, and neutron beam pass through gaps between the anvils. The first high-pressure experiment using this device was conducted at J-PARC and clearly showed the neutron diffraction patterns of Pb. Combining the cubic-anvil high-pressure device with a pulsed neutron source will prove to be a useful tool for neutron diffraction experiments.

Journal Articles

High pressure experiments with the engineering materials diffractometer (BL-19) at J-PARC

Abe, Jun; Hattori, Takanori; Komatsu, Kazuki*; Arima, Hiroshi; Arakawa, Masashi*; Sano, Asami; Kagi, Hiroyuki; Harjo, S.; Ito, Takayoshi; Moriai, Atsushi; et al.

Journal of Physics; Conference Series, 215, p.012023_1 - 012023_6, 2010/03

 Times Cited Count:4 Percentile:83.59

A high-intensity proton accelerator facility named J-PARC has been constructed, and the first neutron beam at J-PARC/MLF was extracted in May of 2008, and user-operation commenced in December of the year. The fist feasibility test of high-pressure neutron experiments were performed with the engineering materials diffractometer "TAKUMI". As results, diffraction profiles of sample embedded in high-pressure devices were obtained. Therefore, it was confirmed that in situ high-pressure neutron diffraction was feasible with the engineering materials diffractometer "TAKUMI".

Journal Articles

Designing PLANET; Neutron beamline for high-pressure material science at J-PARC

Arima, Hiroshi; Hattori, Takanori; Komatsu, Kazuki*; Abe, Jun; Utsumi, Wataru; Kagi, Hiroyuki*; Suzuki, Akio*; Suzuya, Kentaro; Kamiyama, Takashi; Arai, Masatoshi; et al.

Journal of Physics; Conference Series, 215(1), p.012025_1 - 012025_6, 2010/03

The powder diffractometer dedicated to high-pressure experiments (PLANET) is now being constructed on BL11 at the spallation neutron source of J-PARC. PLANET aims to study structures of hydrogen-bearing materials including dense hydrous minerals of the Earth's deep interior, magmas and light element liquids. The instrument will realize diffraction and radiography experiments for powder and liquid/glass samples at high pressures up to 20 GPa and 2000 K. It covers d spacing from 0.2 ${AA}$ to 4.1 ${AA}$ at 90$$^{circ}$$ bank within the first frame.

154 (Records 1-20 displayed on this page)