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Journal Articles

Deuterated malonamide synthesis for fundamental research on solvent extraction systems

Micheau, C.; Ueda, Yuki; Akutsu, Kazuhiro*; Bourgeois, D.*; Motokawa, Ryuhei

Solvent Extraction and Ion Exchange, 41(2), p.221 - 240, 2023/02

 Times Cited Count:0 Percentile:56.57(Chemistry, Multidisciplinary)

Journal Articles

Structure analysis of asymmetric interface using spin-contrast-variation neutron reflectometry

Kumada, Takayuki; Miura, Daisuke*; Akutsu, Kazuhiro*; Oku, Takayuki; Torikai, Naoya*; Niizeki, Tomotake*

Hamon, 32(4), p.165 - 168, 2022/11

We demonstrated the advantage of spin-contrast-variation neutron reflectometry on the structure analysis of buried interface between resin and porous silica layers. The interface structure was not reproduced by the normal Gaussian model, but by the asymmetric interface model where crosslinked polymer chains neither permeate the pore nor follow the surface roughness of the silica layer.

Journal Articles

Structure analysis of a buried interface between organic and porous inorganic layers using spin-contrast-variation neutron reflectivity

Kumada, Takayuki; Miura, Daisuke*; Akutsu, Kazuhiro*; Oishi, Kazuki*; Morikawa, Toshiaki*; Kawamura, Yukihiko*; Suzuki, Junichi*; Oku, Takayuki; Torikai, Naoya*; Niizeki, Tomotake*

Journal of Applied Crystallography, 55(5), p.1147 - 1153, 2022/10

AA2021-0903.pdf:1.06MB

 Times Cited Count:1 Percentile:31.49(Chemistry, Multidisciplinary)

Spin-contrast-variation neutron reflectivity obtains multiple reflectivity curves from a single sample and a single beam source. We used the strong point of the technique to reveal that, although methylated-perhydropolysilazane-derived silica layer has a higher porosity near the interface with acrylic urethane resin, the resin did not permeate the pore network.

Journal Articles

Analysis of the electric double layer structure formed in an ionic liquid using neutron reflectivity

Tamura, Kazuhisa; Akutsu-Suyama, Kazuhiro*; Cagnes, M.*; Darwish, T. A.*

ECS Advances (Internet), 1(2), p.020503_1 - 020503_5, 2022/06

The ionic liquid/Si electrode interface was investigated using neutron reflectivity. We precisely elucidated the structure of the electrical double layer formed at 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([BMIM]TFSA)/Si(100) electrode interface with the orientation of the [BMIM]TFSA molecule using a partially deuterated [BMIM]TFSA. The results revealed that [BMIM]TFSA molecules form a layered structure. Cation and anion molecules are alternatingly stacked and molecules in the first three layers are horizontally oriented to the electrode surface at E = -1.2 V, i.e., on the negatively charged electrode surface. It was also revealed that the imidazole ring in [BMIM] cation is parallel to the electrode surface.

Journal Articles

New design of a sample cell for neutron reflectometry in liquid-liquid systems and its application for studying structures at air-liquid and liquid-liquid interfaces

Akutsu-Suyama, Kazuhiro*; Yamada, Norifumi*; Ueda, Yuki; Motokawa, Ryuhei; Narita, Hirokazu*

Applied Sciences (Internet), 12(3), p.1215_1 - 1215_10, 2022/02

 Times Cited Count:1 Percentile:30(Chemistry, Multidisciplinary)

no abstracts in English

Journal Articles

Improved performance of wide bandwidth neutron-spin polarizer due to ferromagnetic interlayer exchange coupling

Maruyama, Ryuji; Yamazaki, Dai; Aoki, Hiroyuki; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Soyama, Kazuhiko; Bigault, T.*; Saerbeck, T.*; Courtois, P.*

Journal of Applied Physics, 130(8), p.083904_1 - 083904_10, 2021/08

 Times Cited Count:2 Percentile:28.82(Physics, Applied)

Journal Articles

Spin glass behavior and magnetic boson peak in a structural glass of a magnetic ionic liquid

Kofu, Maiko; Watanuki, Ryuta*; Sakakibara, Toshiro*; Kawamura, Seiko; Nakajima, Kenji; Matsuura, Masato*; Ueki, Takeshi*; Akutsu, Kazuhiro*; Yamamuro, Osamu*

Scientific Reports (Internet), 11(1), p.12098_1 - 12098_8, 2021/06

 Times Cited Count:2 Percentile:50.56(Multidisciplinary Sciences)

Journal Articles

Improvement in sputtering rate uniformity over large deposition area of large-scale ion beam sputtering system

Maruyama, Ryuji; Yamazaki, Dai; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Aoki, Hiroyuki; Soyama, Kazuhiko

JPS Conference Proceedings (Internet), 33, p.011092_1 - 011092_6, 2021/03

no abstracts in English

Journal Articles

Development of spin-contrast-variation neutron reflectometry

Kumada, Takayuki; Akutsu, Kazuhiro*; Oishi, Kazuki*; Morikawa, Toshiaki*; Kawamura, Yukihiko*; Sahara, Masae*; Suzuki, Junichi*; Miura, Daisuke*; Torikai, Naoya*

J-PARC 20-02; J-PARC MLF Annual Report 2019, p.38 - 40, 2021/00

Journal Articles

Development of spin-contrast-variation neutron reflectometry for structural analyses of multilayer films

Kumada, Takayuki; Miura, Daisuke*; Akutsu, Kazuhiro*; Suzuki, Junichi*; Torikai, Naoya*

Hamon, 30(4), p.207 - 211, 2020/11

We developed a technique of spin-contrast-variation neutron reflectivity (SCV-NR) for structural analyses of multilayer films. The SCV-NR curves of the polystyrene monolayer film were precisely reproduced using a common set of structural parameters and neutron scattering length density at each proton polarization. This result ensures that SCV-NR curves are not deformed by inhomogeneous PH due to the spin-diffusion mechanism. The number of structural parameters of the lamellar microphase-separated poly(styrene-block-isoprene) thin film is too large to determine with a single unpolarized reflectivity curve only. However, these parameters converged through the global analysis of the SCV-NR curves. In this manner, SCV-NR determines the structure of multilayer films while excluding the incorrect structural model that accidentally accounts for a single unpolarized reflectivity curve only.

Journal Articles

Fine-structure analysis of perhydropolysilazane-derived nano layers in deep-buried condition using polarized neutron reflectometry

Akutsu, Kazuhiro*; Kira, Hiroshi*; Miyata, Noboru*; Hanashima, Takayasu*; Miyazaki, Tsukasa*; Kasai, Satoshi*; Yamazaki, Dai; Soyama, Kazuhiko; Aoki, Hiroyuki

Polymers (Internet), 12(10), p.2180_1 - 2180_10, 2020/10

 Times Cited Count:2 Percentile:7.27(Polymer Science)

Journal Articles

Development of spin-contrast-variation neutron reflectometry for the structural analysis of multilayer films

Kumada, Takayuki; Akutsu, Kazuhiro*; Oishi, Kazuki*; Morikawa, Toshiaki*; Kawamura, Yukihiko*; Sahara, Masae*; Suzuki, Junichi*; Torikai, Naoya*

Journal of Applied Crystallography, 52(5), p.1054 - 1060, 2019/10

AA2018-0116.pdf:0.86MB

 Times Cited Count:3 Percentile:33.01(Chemistry, Multidisciplinary)

We developed a technique of spin-contrast-variation neutron reflectometry (SCV-NR). Polarized-neutron reflectivity curves of film samples vary as a function of their proton-polarization P. The P-dependent reflectivity curves of a polystyrene film was precisely reproduced using a common set of structure parameters and the P-dependent neutron scattering length. The reflectivity curve of poly (styrene-block-isoprene) (PSPI) presented a shoulder attributed to holes with the depth corresponding to one period of periodic lamellae on the free surface only at a specific P. In this way, structural information about specific surfaces or interfaces can be obtained by controlling the P.

Journal Articles

Controlled deuterium labelling of imidazolium ionic liquids to probe the fine structure of the electrical double layer using neutron reflectometry

Akutsu, Kazuhiro*; Cagnes, M.*; Tamura, Kazuhisa; Kanaya, Toshiji*; Darwish, T. A.*

Physical Chemistry Chemical Physics, 21(32), p.17512 - 17516, 2019/08

 Times Cited Count:10 Percentile:53.94(Chemistry, Physical)

We combined the deuterium labeling and neutron reflectivity techniques to determine the fine structure of the electric double layer structure in an imidazolium ionic liquid (IL). For this, a simple and large scale deuteration method for imidazolium ILs was developed, where the deuteration level can be systematically controlled.

Journal Articles

Complexation properties and structural character of lanthanides complexes of $$O,N$$-hetero donor ligand BIZA

Kobayashi, Toru; Akutsu, Kazuhiro*; Nakase, Masahiko*; Suzuki, Shinichi; Shiwaku, Hideaki; Yaita, Tsuyoshi

Separation Science and Technology, 54(13), p.2077 - 2083, 2019/02

 Times Cited Count:5 Percentile:22.87(Chemistry, Multidisciplinary)

Development of separation reagent, which can efficiently separate lanthanides, is of increasing importance because it concerns establishment of purification and recycle techniques rare-earth elements. In our research group, several hetero donor type ligands, which have both oxygen and heterocyclic nitrogen atoms as donor atoms, were developed and revealed that this type of ligands show the selective complexation with specific lanthanide. In this paper, we will discuss the lanthaides complexation properties of the hetero donor type ligand containing benzimidazole group as nitrogen donor ($$N$$-methyl-$$N$$-phenyl-2-(1$$H$$-benzimidazol-2-yl)-pyridine-6-carboxamide) based on structural investigation by crystallography.

Journal Articles

Development of high-polarization Fe/Ge neutron polarizing supermirror; Possibility of fine-tuning of scattering length density in ion beam sputtering

Maruyama, Ryuji; Yamazaki, Dai; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Aoki, Hiroyuki; Takeda, Masayasu; Soyama, Kazuhiko

Nuclear Instruments and Methods in Physics Research A, 888, p.70 - 78, 2018/04

 Times Cited Count:3 Percentile:30.45(Instruments & Instrumentation)

The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with $$m=5$$ fabricated showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the $$q_z$$ range where the correction for the polarization inefficiencies of the beamline works properly.

JAEA Reports

Deuterated Materials Enhancing Neutron Science for Structure Function Applications; October 19th-20th, 2017, Ibaraki Quantum Beam Research Center

Akutsu, Kazuhiro*; Adachi, Motoyasu*; Kawakita, Yukinobu

JAEA-Review 2018-002, 36 Pages, 2018/03

JAEA-Review-2018-002.pdf:4.67MB

Since J-PARC started operation for user programs with high-intensity pulsed neutron beams, many material and life science studies have been carried out at J-PARC. Since partial or complete deuteration of organic compounds for contrast variation in the scattering length densities of materials is one of the most effective techniques in the application of neutron scattering analysis, deuterated materials have led to significant progress in our understanding of the structure of novel organic materials. Aiming at accelerating development of deuteration activities in our country, an international workshop "Deuterated Materials Enhancing Neutron Science for Structure Function Applications" was held as a J-PARC Workshop at Ibaraki Quantum Beam Research Center from 19th October to 20th October in 2017. In this workshop, the chemical/biological deuteration activities and recent scientific results of deuterated materials enhancing neutron study in Japan and other countries were discussed by domestic/foreign deuteration and neutron scientists. This is a report of the workshop summarized by organizers.

Journal Articles

A Novel microemulsion phase transition; Toward the elucidation of third-phase formation in spent nuclear fuel reprocessing

Mu, J.*; Motokawa, Ryuhei; Akutsu, Kazuhiro*; Nishitsuji, Shotaro*; Masters, A. J.*

Journal of Physical Chemistry B, 122(4), p.1439 - 1452, 2018/02

 Times Cited Count:33 Percentile:72.79(Chemistry, Physical)

Journal Articles

Small-angle neutron scattering study of specific interaction and coordination structure formed by mono-acetyl-substituted dibenzo-20-crown-6-ether and cesium ions

Motokawa, Ryuhei; Kobayashi, Toru; Endo, Hitoshi*; Ikeda, Takashi; Yaita, Tsuyoshi; Suzuki, Shinichi; Narita, Hirokazu*; Akutsu, Kazuhiro*; Heller, W. T.*

Journal of Nuclear Science and Technology, 53(8), p.1205 - 1211, 2016/08

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

Journal Articles

Comparative molecular dynamics study on tri-$$n$$-butyl phosphate in organic and aqueous environments and its relevance to nuclear extraction processes

Mu, J.*; Motokawa, Ryuhei; Williams, C. D.*; Akutsu, Kazuhiro*; Nishitsuji, Shotaro*; Masters, A. J.*

Journal of Physical Chemistry B, 120(23), p.5183 - 5193, 2016/06

 Times Cited Count:27 Percentile:60.57(Chemistry, Physical)

Journal Articles

Application and outlook of the pulsed neutron beam at J-PARC, 3; Introduction of high-pressure science and surface/interface analysis at J-PARC

Hattori, Takanori; Akutsu, Kazuhiro*; Suzuki, Junichi*

Bunseki, 2015(2), p.58 - 64, 2015/02

In the J-PARC MLF, 18 beamlines has been constructed and many studies on scientific and industrial use have been performed. This paper introduces the high-pressure science at high-pressure neutron diffractometer "PLANET" and surface/interface structure analysis at vertical sample geometry polarized neutron reflectometer "SHARAKU".

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