Microscopic origin of the spin-reorientation transition in the kagome topological magnet TbMnSn

Huang, Z.*; Wang, W.*; Ye, H.*; Bao, S.*; Shangguan, Y.*; Liao, J.*; Cao, S.*; Kajimoto, Ryoichi; Ikeuchi, Kazuhiko*; Deng, G.*; et al.

Physical Review B, 109(1), p.014434_1 - 014434_9, 2024/01

https://doi.org/10.1103/PhysRevB.109.014434

A Colossal barocaloric effect induced by the creation of a high-pressure phase

Jiang, X.*; Hattori, Takanori; Xu, X.*; Li, M.*; Yu, C.*; Yu, D.*; Mole, R.*; Yano, Shinichiro*; Chen, J.*; He, L.*; et al.

Materials Horizons, 10(3), p.977 - 982, 2023/03

https://doi.org/10.1039/d2mh00905f

As a promising environment-friendly alternative to current vapor-compression refrigeration, solid-state refrigeration based on the barocaloric effect has been attracting world wide attention. Generally, both phases in which a barocaloric effect occurs are present at ambient pressure. Here, instead, we demonstrate that KPF exhibits a colossal barocaloric effect due to the creation of a high-pressure rhombohedral phase. The phase diagram is constructed based on pressure-dependent calorimetric, Raman scattering, and neutron diffraction measurements. The present study is expected to provide an alternative routine to colossal barocaloric effects through the creation of a high-pressure phase.

Characterization and corrosion behavior of Al-added high Mn ODS austenitic steels in oxygen-saturated lead-bismuth eutectic

Haoran, W.*; Yu, H.*; Liu, J.*; Kondo, Sosuke*; Okubo, Nariaki; Kasada, Ryuta*

Corrosion Science, 209, p.110818_1 - 110818_12, 2022/12

https://doi.org/10.1016/j.corsci.2022.110818

The corrosion behavior of newly developed AlO forming high Mn oxide dispersion strengthened (ODS) austenitic steels was examined in oxygen-saturated lead-bismuth eutectic at 450C for 430 h. Compared with non-ODS steels, the ODS steels possessed superior resistance to corrosion and spallation. The high density grain boundaries in the ODS steels acted as channels for the rapid outward diffusion of metallic elements, forming an internal continuous CrO scale at the original surface. Accelerated Al diffusion, along with oxidation prevention by the external (Fe, Mn) oxide scale and the internal CrO scale, jointly resulted in the formation of a continuous Al-rich oxide scale in ODS-7Al steel, contributing to its superior corrosion resistance.

Crystallinity in periodic nanostructure surface on Si substrates induced by near- and mid-infrared femtosecond laser irradiation

Miyagawa, Reina*; Kamibayashi, Daisuke*; Nakamura, Hirotaka*; Hashida, Masaki*; Zen, H.*; Somekawa, Toshihiro*; Matsuoka, Takeshi*; Ogura, Hiroyuki*; Sagae, Daisuke*; Seto, Yusuke*; et al.

Scientific Reports (Internet), 12, p.20955_1 - 20955_8, 2022/12

https://doi.org/10.1038/s41598-022-25365-1

We evaluated Laser-Induced Periodic Surface Structure (LIPSS) crystal structures using the stress imaging station at BL22XU of JAEA-BL on SPring-8. Crystallization of LIPPS was used different two types laser these are Ti:Sapphire laser (wavelength: 800 nm) and MIR-FEL (mid-infrared free electron laser, wavelength 11.4 m). These lasers are different in the laser pulse structure and the wavelength. We investigated on the effects of formed LIPSS crystallization using different kind of laser. Measured synchrotron X-ray energy is 30 keV and beam size is 20 m. Detector of diffracted X-ray is two-dimensional detector (PILATUS300K, DECTRIS). LIPSS formed using Ti:Sapphire laser has deformed structure with good crystallinity. LIPSS formed using MIR-FEL has dislocation or fault without structural stress. These results show depending on select of laser forming LIPPS structure. These information becomes important a point of the functional application of LIPSS.

Assessment of radioactive contamination and effectiveness of remedial measures in urban environments, Report of Working Group 2, Modelling and Data for Radiological Impact Assessments (MODARIA) Programme

Boznar, M. Z.*; Charnock, T. W.*; Chouhan, S. L.*; Grsic, Z.*; Halsall, C.*; Heinrich, G.*; Helebrant, J.*; Hettrich, S.*; Kua, P.*; Mancini, F.*; et al.

IAEA-TECDOC-2001, 226 Pages, 2022/06

https://www.iaea.org/publications/15122/assessment-of-radioactive-contamination-and-effectiveness-of-remedial-measures-in-urban-environments

The IAEA organized a programme from 2012 to 2015 entitled Modelling and Data for Radiological Impact Assessments (MODARIA), which aimed to improve capabilities in the field of environmental radiation dose assessment by acquiring improved data, model testing and comparison of model inputs, assumptions and outputs, reaching a consensus on modelling philosophies, aligning approaches and parameter values, developing improved methods and exchanging information. This publication describes the activities of Working Group 2, Exposures in Contaminated Urban Environments and Effect of Remedial Measures.

Long decay length of magnon-polarons in BiFeO/LaSrMnO heterostructures

Zhang, J.*; Chen, M.*; Chen, J.*; Yamamoto, Kei; Wang, H.*; Hamdi, M.*; Sun, Y.*; Wagner, K.*; He, W.*; Zhang, Y.*; et al.

Nature Communications (Internet), 12, p.7258_1 - 7258_8, 2021/12

https://doi.org/10.1038/s41467-021-27405-2

Gapless spin liquid in a square-kagome lattice antiferromagnet

Fujihara, Masayoshi*; Morita, Katsuhiro*; Mole, R.*; Mitsuda, Setsuo*; Toyama, Takami*; Yano, Shinichiro*; Yu, D.*; Sota, Shigetoshi*; Kuwai, Tomohiko*; Koda, Akihiro*; et al.

Nature Communications (Internet), 11, p.3429_1 - 3429_7, 2020/07

https://doi.org/10.1038/s41467-020-17235-z

Colossal barocaloric effects in plastic crystals

Li, B.*; Kawakita, Yukinobu; Kawamura, Seiko; Sugahara, Takeshi*; Wang, H.*; Wang, J.*; Chen, Y.*; Kawaguchi, Saori*; Kawaguchi, Shogo*; Ohara, Koji*; et al.

Nature, 567(7749), p.506 - 510, 2019/03

https://doi.org/10.1038/s41586-019-1042-5

Refrigeration is of vital importance for modern society for example, for food storage and air conditioning- and 25 to 30% of the world's electricity is consumed for refrigeration. Current refrigeration technology mostly involves the conventional vapour compression cycle, but the materials used in this technology are of growing environmental concern because of their large global warming potential. As a promising alternative, refrigeration technologies based on solid-state caloric effects have been attracting attention in recent decades. However, their application is restricted by the limited performance of current caloric materials, owing to small isothermal entropy changes and large driving magnetic fields. Here we report colossal barocaloric effects (CBCEs) (barocaloric effects are cooling effects of pressure-induced phase transitions) in a class of disordered solids called plastic crystals. The obtained entropy changes in a representative plastic crystal, neopentylglycol, are about 389 joules per kilogram per kelvin near room temperature. Pressure-dependent neutron scattering measurements reveal that CBCEs in plastic crystals can be attributed to the combination of extensive molecular orientational disorder, giant compressibility and highly anharmonic lattice dynamics of these materials. Our study establishes the microscopic mechanism of CBCEs in plastic crystals and paves the way to next-generation solid-state refrigeration technologies.

Consideration of the oxide particle-dislocation interaction in 9Cr-ODS steel

Ijiri, Yuta*; Ono, Naoko*; Ukai, Shigeharu*; Yu, H.*; Otsuka, Satoshi; Abe, Yosuke; Matsukawa, Yoshitaka*

Philosophical Magazine, 97(13), p.1047 - 1056, 2017/02

https://doi.org/10.1080/14786435.2017.1288942

The interaction between oxide particles and dislocations in a 9Cr-ODS ferritic steel is investigated by both static and in-situ TEM observation under dynamic straining conditions and room temperature. The measured obstacle strength () of the oxide particles was no greater than 0.80 and the average was 0.63. The dislocation loops around some coarsened particles were also observed. The calculated obstacle strength by a stress formula of the Orowan interaction is nearly equaled to the average experimental value. Not only cross-slip system but also the Orowan interaction should be considered as the main interaction mechanism between oxide particles and dislocation in 9Cr-ODS ferritic steel.

Cosmic-ray test of a time-of-flight detector for double-strangeness experiments at J-PARC

Kim, S. H.*; Hwang, S.; Ahn, J. K.*; Ekawa, Hiroyuki; Hayakawa, Shuhei; Hong, B.*; Hosomi, Kenji; Imai, Kenichi; Kim, M. H.*; Lee, J. Y.*; et al.

Nuclear Instruments and Methods in Physics Research A, 795, p.39 - 44, 2015/09

https://doi.org/10.1016/j.nima.2015.05.046