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Journal Articles

Development of spin-contrast-variation neutron powder diffractometry for extracting the structure factor of hydrogen atoms

Miura, Daisuke*; Kumada, Takayuki; Sekine, Yurina; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Ohara, Takashi; Takata, Shinichi; Hiroi, Kosuke; Morikawa, Toshiaki*; et al.

Journal of Applied Crystallography, 54(2), p.454 - 460, 2021/04

 Times Cited Count:0 Percentile:0.02(Chemistry, Multidisciplinary)

We developed a spin-contrast-variation neutron powder diffractometry technique that extracts the structure factor of hydrogen atoms, namely, the contribution of hydrogen atoms to a crystal structure factor. Crystals of L-glutamic acid were dispersed in a dpolystyrene matrix containing 4-methacryloyloxy-2,2,6,6,-tetramethyl-1-piperidinyloxy (TEMPO methacrylate) to polarize their proton spins dynamically. The intensities of the diffraction peaks of the sample changed according to the proton polarization, and the structure factor of the hydrogen atoms was extracted from the proton-polarization dependent intensities. This technique is expected to enable analyses of the structures of hydrogen-containing materials that are difficult to determine with conventional powder diffractometry.

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, p.38 - 40, 2021/00

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:1 Percentile:21.27(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

Measurement of neutron scattering cross section of nano-diamond with particle diameter of approximately 5 nm in energy range of 0.2 meV to 100 meV

Teshigawara, Makoto; Tsuchikawa, Yusuke*; Ichikawa, Go*; Takata, Shinichi; Mishima, Kenji*; Harada, Masahide; Oi, Motoki; Kawamura, Yukihiko*; Kai, Tetsuya; Kawamura, Seiko; et al.

Nuclear Instruments and Methods in Physics Research A, 929, p.113 - 120, 2019/06

 Times Cited Count:7 Percentile:75.46(Instruments & Instrumentation)

A nano-diamond is an attractive neutron reflection material below cold neutron energy. The total neutron cross section of a nano-diamond was derived from a neutron transmission measurement over the neutron energy range of 0.2 meV to 100 meV because total neutron cross section data were not available. The total cross section of a nano-diamond with particle size of approximately 5 nm increased with a decrease in neutron energy to 0.2 meV. It was approximately two orders of magnitude larger than that of graphite at 0.2 meV. The contribution of inelastic scattering to the total cross section was to be shown negligible small at neutron energies of 1.2, 1.5, 1.9, 2.6, and 5.9 meV in the inelastic neutron scattering measurement. Moreover, small-angle neutron scattering measurements of the nano-diamond showed a large scattering cross section in the forward direction for low neutron energies.

Journal Articles

Time-of-flight elastic and inelastic neutron scattering studies on the localized 4d electron layered perovskite La$$_5$$Mo$$_4$$O$$_{16}$$

Iida, Kazuki*; Kajimoto, Ryoichi; Mizuno, Yusuke*; Kamazawa, Kazuya*; Inamura, Yasuhiro; Hoshikawa, Akinori*; Yoshida, Yukihiko*; Matsukawa, Takeshi*; Ishigaki, Toru*; Kawamura, Yukihiko*; et al.

Journal of the Physical Society of Japan, 86(6), p.064803_1 - 064803_6, 2017/06

 Times Cited Count:1 Percentile:15.72(Physics, Multidisciplinary)

Oral presentation

Low-temperature physical properties of PrPd$$_3$$

Kikkawa, Akiko*; Suzuki, Hiroyuki*; Terada, Noriki*; Kawamura, Yukihiko*; Kitazawa, Hideaki*; Matsuda, Masaaki; Metoki, Naoto

no journal, , 

no abstracts in English

Oral presentation

Neutron diffraction study of rare-earth compound Ho$$_5$$Pd$$_2$$ with a large magnetocaloric effect

Kitazawa, Hideaki*; Kawamura, Yukihiko*; Terada, Noriki*; Mamiya, Hiroaki*; Suzuki, Hiroyuki*; Doenni, A.*; Kaneko, Koji; Metoki, Naoto; Igawa, Naoki

no journal, , 

We have performed neutron powder diffraction experiments at JRR-3 using polycrystalline Ho$$_5$$Pd$$_2$$. The magnetic peaks with a propagation vector k = (0.18, 0.18, 0.18) are gradually developing below about 100 K. The peak width is significantly broader than an experimental resolution even temperature is 5 K. These results indicate that Ho$$_5$$Pd$$_2$$ is a short-range ordered antiferromagnet with a long wave length.

Oral presentation

Neutron scattering study toward to development of energy-efficient environment-friendly refrigeration technology

Kitazawa, Hideaki*; Kawamura, Yukihiko*; Mamiya, Hiroaki*; Terada, Noriki*; Suzuki, Hiroyuki*; Tsujii, Naohito*; Doenni, A.*; Kaneko, Koji; Metoki, Naoto; Igawa, Naoki; et al.

no journal, , 

In this paper, we will demonstrate some application of neutron scattering for magnetic refrigerant materials Ho$$_5$$Pd$$_2$$ and dilute spinel ferrites. In order to determine the magnetic structure, we have performed neutron powder diffraction experiments at JRR-3. The magnetic peaks with a propagation vector k = (0.18, 0.18, 0.18) are gradually developing. The peak width is significantly broader even 5 K, indicating a short-range order with a long wave length.

Oral presentation

Giant magnetocaloric effect and short-range ordering of magnetic refrigerant materials R$$_5$$Pd$$_2$$(R=Tb, Ho)

Kitazawa, Hideaki*; Kawamura, Yukihiko*; Keller, L.*; Toyoizumi, Saori*; Terada, Noriki*; Suzuki, Hiroyuki*; Mamiya, Hiroaki*; Doenni, A.*; Lee, S.*; Metoki, Naoto; et al.

no journal, , 

Neutron Scattering study has been carried out in order to reveal the magnetic structure of the antiferromagnet Ho$$_5$$Pd$$_2$$, which shows giant magnetocaloric effect. We observed short rage magnetic order at k=0.18, 0.18, 0.18 above the antiferromagnetic transition temperature $$T$$$$_N$$. Tb$$_5$$Pd$$_2$$ also showed magnetic short range correlation above the temperature higher than 2$$times$$$$T$$$$_N$$.

Oral presentation

Development of dynamic nuclear polarization system for neutron reflectivity measurement

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

no journal, , 

Scattering power of neutrons against protons depends remarkably on relative directions of their spins. So, polarized neutron scattering profiles vary as a function of proton polarization of measuring specimen. We can extract fruitful structural information from these profiles. This technique named "spin-contrast variation" has been used to study meso-scale bulk structure using small-angle neutron scattering. Now, we plan to apply the spin-contrast variation technique to study surface structure using neutron reflectivity measurements. The spin-contrast neutron reflectivity measurement will determine surface structure of complex soft materials such as adhesives.

Oral presentation

Development of dynamic nuclear polarization system for neutron reflectrometry

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

no journal, , 

no abstracts in English

Oral presentation

Development of dynamic nuclear polarization system for neutron reflectrometry

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

no journal, , 

no abstracts in English

Oral presentation

Polarized neutron reflectometry using proton-polarization technique

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

no journal, , 

Scattering power of neutron against proton remarkably depends on relative direction of these spins. Spin contrast variation (SCV) is a technique to determine structure of composite materials from their polarized neutron scattering profiles that vary as a function of proton polarization. Very recently, we succeeded in the first SCV neutron reflectometry measurement. We determined roughness of two surfaces of a thin-film polymer from the SCV neutron reflection curves. We will use this technique to study structures of multilayered films such as coupling agents (glues) between organic and inorganic materials.

Oral presentation

Development of spin contrast variation neutron reflectometry

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

no journal, , 

Scattering power of neutron against proton remarkably depends on relative direction of these spins. Spin contrast variation (SCV) is a technique to determine structure of composite materials from their polarized neutron scattering profiles that vary as a function of proton polarization. Very recently, we succeeded in the first SCV neutron reflectometry measurement. We determined roughness of two surfaces of a thin-film polymer from the SCV neutron reflection curves. We will use this technique to study structures of multilayered films such as coupling agents (glues) between organic and inorganic materials.

Oral presentation

Development of spin contrast variation neutron reflectometry

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

no journal, , 

We have developed a technique of spin contrast variation neutron reflectometry (SCV-NR). The reflectivity curve of the polarized neutrons nonsimilarly varies as a function of proton polarization PH of a polymer thin film on silicon substrate. The PH-dependent reflectivity curve determines the roughnesses of the surface and interface of the polymer thin film, whereas single reflection curve of non-polarized neutrons cannot determine uniquely. We consider that the SCV-NR would be a promising technique to determine surface and interface structure of thin films of soft materials.

Oral presentation

Sample environment at the small and wide angle neutron scattering instrument TAIKAN of J-PARC

Hiroi, Kosuke; Takata, Shinichi; Oishi, Kazuki*; Iwase, Hiroki*; Kawamura, Yukihiko*; Morikawa, Toshiaki*; Sahara, Masae*; Suzuki, Junichi*

no journal, , 

Oral presentation

Performance measurements of TOF-SANS (TAIKAN) at J-PARC; Results of soft matter materials

Takata, Shinichi; Iwase, Hiroki*; Suzuki, Junichi*; Oishi, Kazuki*; Kawamura, Yukihiko*; Morikawa, Toshiaki*; Inamura, Yasuhiro; Hiroi, Kosuke

no journal, , 

The small- and wide-angle neutron scattering instrument (TAIKAN) was installed in the Materials and Life Science Experimental Facility (MLF) of J-PARC, which was designed for efficient measurement in the range from sub-nanometre to micrometre scale. Therefor, TAIKAN is used in various research fields. In order to enable measurement of smaller scattering angles, recently, the scintillation 2D detector with a high spatial resolution was installed at the behind of small-angle detector bank. In this report, we will introduce on the results of commissioning measurements with 2D detector and the research results on soft matter materials using TAIKAN.

Oral presentation

Development of spin-contrast-variation neutron reflectometry

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

no journal, , 

We developed a technique of spin-contrast-variation neutron reflectometry (SCV-NR). Polarized-neutron reflectivity curves of a styrene homopolymer film vary as a function of their proton-polarization, P$$_H$$, coherently with what expected when the films are homogeneously polarized. This result ensures that the SCV-NR curves are not deformed by inhomogeneous P$$_H$$ in the film, but determine the structures of surfaces and interfaces properly. Conventional unpolarized neutron reflectivity UNR and negatively-polarized SCV-NR curves of poly(styrene-block-isoprene) (PSPI) films are reproduced by the model that the film has a flat free surface, but positively-polarized SCV-NR curves are not. We found from the global fit that the holes with the depth corresponding to one period of periodic lamellae are produced on the free surface of the PSPI films, whose reflection is hidden by strong one from the PSPI-Si interface in the UNR and negatively-polarized SCV-NR curves.

Oral presentation

Magnetic lens system for focusing-geometry small-angle neutron scattering at MLF BL15 TAIKAN

Hiroi, Kosuke; Takata, Shinichi; Oishi, Kazuki*; Kawamura, Yukihiko*; Iwase, Hiroki*; Shinohara, Takenao; Oku, Takayuki; Suzuki, Junichi*

no journal, , 

Oral presentation

Short-range ordering of magnetic refrigerant materials $$R_5$$Pd$$_2$$ (R = Ho, Tb) by neutron diffraction

Kitazawa, Hideaki*; Kawamura, Yukihiko*; Keller, L.*; Terada, Noriki*; Suzuki, Hiroyuki*; Mamiya, Hiroaki*; Doenni, A.*; Lee, S.*; Metoki, Naoto; Kaneko, Koji; et al.

no journal, , 

Antiferromagnetic Ho$$_5$$Pd$$_2$$($$T_{rm N} = 28$$K) with cubic structure accompanies very large magneto-calorimetric eefect (MCE) at 34K. We showed that this compound remains short range order with incommensurate modulation $$k=$$[0.18,0.18,0.18] developing at low temperatures. The short range correlation increases below 70K in Tb$$_5$$Pd$$_2$$($$T_g = 70$$K).

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