Role of solute hydrogen on mechanical property enhancement in Fe-24Cr-19Ni austenitic steel; An neutron diffraction study

Ito, Tatsuya; Ogawa, Yuhei*; Gong, W.; Mao, W.*; Kawasaki, Takuro; Okada, Kazuho*; Shibata, Akinobu*; Harjo, S.

Acta Materialia, 287, p.120767_1 - 120767_16, 2025/04

https://doi.org/10.1016/j.actamat.2025.120767

Crystal structures of ReO under hydrostatic pressure; A Combined neutron, X-ray, Raman, and first-principles calculation study

Efthimiopoulos, I.*; Klotz, S.*; Kunc, K.*; Baptiste, B.*; Chauvigne, P.*; Hattori, Takanori

Physical Review B, 111(13), p.134103_1 - 134103_13, 2025/04

https://doi.org/10.1103/PhysRevB.111.134103

We present a comprehensive study of the high pressure behaviour of ReO using X-ray and neutron diffraction, Raman scattering and first-principles calculations to 15 GPa. We show that the ambient pressure structure converts at 0.7 GPa in a continuous phase transition directly to a cubic phase with space group and rhombohedral structures in this pressure range are an artifact due to an alteration of the sample by high-flux synchrotron X-ray radiation. The structural pressure dependence of the O samples are presented. The data shed light onto the unusual transition and densification mechanism due to progressive tilting of essentially rigid ReO octahedra.

Solid-state Alder-ene reaction of 1-hexene under high pressure

Xu, J.*; Lang, P.*; Liang, S.*; Zhang, J.*; Fei, Y.*; Wang, Y.*; Gao, D.*; Hattori, Takanori; Abe, Jun*; Dong, X.*; et al.

Journal of Physical Chemistry Letters (Internet), p.2445 - 2451, 2025/00

https://doi.org/10.1021/acs.jpclett.4c03696

The Alder-ene reaction is a chemical reaction between an alkene with an allylic hydrogen, and it provides an efficient method to construct the C-C bond. Traditionally, this reaction requires catalysts, high temperatures, or photocatalysis. In this study, we reported a high-pressure-induced solid-state Alder-ene reaction of 1-hexene at room temperature without a catalyst. 1-Hexene crystallizes at 4.3 GPa and polymerizes at 18 GPa, forming olefins. By exploring gas chromatography-mass spectrometry, we discovered that 1-hexene generates dimeric products through the Alder-ene reaction under high pressures. The in situ neutron diffraction shows that the reaction process did not obey the topochemical rule. A six-membered ring transition state including one C-H bond and two alkene bonds was evidenced by the theoretical calculation, whose energy obviously decreased when compressed to 20 GPa. Our work offers a novel and promising method to realize the Alder-ene reaction at room temperature without a catalyst, expanding the application of this important reaction.

Report on research and development of neutron beam utilization at JRR-3 for internal use in FY2021 and FY2022

Materials Sciences Research Center

JAEA-Review 2024-037, 141 Pages, 2024/11

JAEA-Review-2024-037.pdf:13.08MB

Fifteen neutron beam experimental instruments managed by JAEA are installed in JRR-3 (Japan Research Reactor No.3) and are available for internal use including upgrading of instruments and for external users to produce various research results. This report summarizes the progress of internal application research and technical development such as upgrading of neutron beam instruments in the fiscal years 2021 and 2022 after the restart of operation.

neutron diffraction study to elucidate hydrogen effect on the deformation mechanism in Type 310S austenitic stainless steel

Ito, Tatsuya; Ogawa, Yuhei*; Gong, W.; Mao, W.*; Kawasaki, Takuro; Okada, Kazuho*; Shibata, Akinobu*; Harjo, S.

Proceedings of the 7th International Symposium on Steel Science (ISSS 2024), p.237 - 240, 2024/11

https://doi.org/10.2355/isijisss.2024.0_237

Pearlite growth kinetics in Fe-C-Mn eutectoid steels; Quantitative evaluation of energy dissipation at pearlite growth front via experimental approaches

Zhang, Y.-J.*; Umeda, Takemasa*; Morooka, Satoshi; Harjo, S.; Miyamoto, Goro*; Furuhara, Tadashi*

Metallurgical and Materials Transactions A, 55(10), p.3921 - 3936, 2024/10

https://doi.org/10.1007/s11661-024-07518-1

Anomalous dislocation response to deformation strain in CrFeCoNiPd high-entropy alloys with nanoscale chemical fluctuations

Ying, H.*; Yang, X.*; He, H.*; Yan, A.*; An, K.*; Ke, Y.*; Wu, Z.*; Tang, S.*; Zhang, Z.*; Dong, H.*; et al.

Scripta Materialia, 250, p.116181_1 - 116181_7, 2024/09

https://doi.org/10.1016/j.scriptamat.2024.116181

Effects of loading direction on the anisotropic tensile properties of duplex stainless steels based on phase strains obtained by in situ neutron diffraction experiments

Matsushita, Akira*; Tsuchida, Noriyuki*; Ishimaru, Eiichiro*; Hirakawa, Naoki*; Gong, W.; Harjo, S.

Journal of Materials Engineering and Performance, 33(13), p.6352 - 6361, 2024/07

https://doi.org/10.1007/s11665-023-08424-0

Stress evaluation using multi-peaks

Harjo, S.; Gong, W.; Kawasaki, Takuro

Nihon Zairyo Gakkai Dai-58-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.51 - 54, 2024/07

Mechanism of strength increase in high-strength magnesium alloys elucidated by in-situ pulsed neutron diffraction experiments

Harjo, S.

Isotope News, (793), p.13 - 16, 2024/06

no abstracts in English