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

https://doi.org/10.1107/S1600576721000303

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.

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

https://doi.org/10.1107/S1600576719010616

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.

Time-of-flight elastic and inelastic neutron scattering studies on the localized 4d electron layered perovskite LaMoO

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

https://doi.org/10.7566/JPSJ.86.064803

Neutron diffraction study of rare-earth compound HoPd 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 HoPd. 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 HoPd is a short-range ordered antiferromagnet with a long wave length.

Giant magnetocaloric effect and short-range ordering of magnetic refrigerant materials RPd(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 HoPd, which shows giant magnetocaloric effect. We observed short rage magnetic order at k=0.18, 0.18, 0.18 above the antiferromagnetic transition temperature . TbPd also showed magnetic short range correlation above the temperature higher than 2.

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

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.

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.

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.

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, ,