Elucidation of solid particle interfacial phenomena in liquid sodium; Magnetic interactions on liquid metal and solid atoms at the solid interface

Tei, C.; Otaka, Masahiko; Kuwahara, Daisuke*

Chemical Physics Letters, 829, p.140755_1 - 140755_6, 2023/10

https://doi.org/10.1016/j.cplett.2023.140755

We were able to detect the nuclear magnetic resonance (NMR) signal of a liquid sodium clinging to the interface of solid metal particles for the first time. In this study, we confirmed the difference in the relaxation times due to the difference in the interactions between liquid sodium and metal particles suspended in the liquid sodium. It was found that the surface of the micro titanium particles and liquid metallic sodium interact physically, not chemically.

Tolerance of anhydrobiotic eggs of the tardigrade to extreme environments

Horikawa, Daiki*; Yamaguchi, Ayami*; Sakashita, Tetsuya; Tanaka, Daisuke*; Hamada, Nobuyuki*; Yukuhiro, Fumiko*; Kuwahara, Hirokazu*; Kunieda, Takekazu*; Watanabe, Masahiko*; Nakahara, Yuichi*; et al.

Astrobiology, 12(4), p.283 - 289, 2012/04

https://doi.org/10.1089/ast.2011.0669

We examined the hatchability of hydrated and anhydrobiotic eggs of the tardigrade to hatch after ionizing irradiation (helium ions), extremely low and high temperatures, and high vacuum. Anhydrobiotic eggs (50% lethal dose; 1690 Gy) were substantially more radioresistant than hydrated ones (50% lethal dose; 509 Gy). Anhydrobiotic eggs also have a broader temperature resistance compared with hydrated ones. Over 70% of the anhydrobiotic eggs treated at high and low temperatures, but all of the hydrated eggs failed to hatch. After exposure to high vacuum conditions, the hatchability of the anhydrobiotic eggs was comparable to that of untreated control eggs.

Pressure-induced antiferromagnetic order in filled skutterudite PrFeP studied by single-crystal high-pressure neutron diffraction

Osakabe, Toyotaka; Kuwahara, Keitaro*; Kawana, Daichi*; Iwasa, Kazuaki*; Kikuchi, Daisuke*; Aoki, Yuji*; Kogi, Masafumi*; Sato, Hideyuki*

Journal of the Physical Society of Japan, 79(3), p.034711_1 - 034711_7, 2010/03

https://doi.org/10.1143/JPSJ.79.034711

Single-crystal neutron diffraction on the pressure-induced insulating phase of PrFeP

Kawana, Daichi*; Osakabe, Toyotaka; Kuwahara, Keitaro*; Kikuchi, Daisuke*; Aoki, Yuji*; Kogi, Masafumi*; Sato, Hideyuki*

no journal, , 

no abstracts in English

Evaluation of dispersion and aggregation of nanoparticles in liquid metal via NMR

Tei, C.; Otaka, Masahiko; Kuwahara, Daisuke*

no journal, , 

Evaluation of nanoparticles in liquid phase dispersants has been carried out by using methods such as particle size measurement and transmission electron microscopy. It is difficult to apply it to chemically active liquid metals (impermeable to visible light) that cannot be handled in the atmosphere. In this study, the NMR methods based on evaluating the interfacial state of sodium-nanoparticles in liquid metallic sodium (Na) was investigated for metallic nanoparticle dispersions. There are two types liquid Na in contact with the surface of the nanoparticles (atomic state bound to the particle surface) and liquid Na away from the particle surface (free atomic state). The relaxation time of each depends on the bound state of the atoms. The clear difference in relaxation times and the relative specific surface area estimated from the relaxation times are also obtained, leading to the development of methods for assessing the state of nanoparticles in liquid metal.