Polarized neutron transmission spectroscopy on carbon steel

Mamiya, Hiroaki*; Oba, Yojiro; Terada, Noriki*; Hiroi, Kosuke; Shinohara, Takenao

IEEE Transactions on Magnetics, 59(11), p.6500505_1 - 6500505_5, 2023/11

https://dx.doi.org/10.1109/TMAG.2023.3311456

Magnetic structural analysis of nanocrystalline soft magnets by small-angle neutron scattering

Mamiya, Hiroaki*; Oba, Yojiro; Hiroi, Kosuke; Miyatake, Takayuki*; Gautam, R.*; Sepehri-Amin, H.*; Okubo, Tadakatsu*

IEEE Magnetics Letters, 14, p.7100105_1 - 7100105_5, 2023/02

https://doi.org/10.1109/LMAG.2023.3242108

Characterization of spin superstructures using neutron transmission spectra

Mamiya, Hiroaki*; Oba, Yojiro; Oikawa, Kenichi

Shiki, 39, P. 4, 2018/06

http://www.j-neutron.com/pdf/Vol39.pdf

no abstracts in English

Nearly localized nature of electrons in CeIn (=Rh, Ir)

Fujimori, Shinichi; Okane, Tetsuo; Okamoto, Jun; Mamiya, Kazutoshi; Muramatsu, Yasuji; Fujimori, Atsushi*; Harima, Hisatomo*; Aoki, Dai*; Ikeda, Shugo*; Shishido, Hiroaki*; et al.

Physical Review B, 67(14), p.144507_1 - 144507_5, 2003/04

https://doi.org/10.1103/PhysRevB.67.144507

We have performed angle-resolved photoemission spectroscopy (~eV) and 3-4 resonant photoemission spectroscopy (~eV) studies on the layered cerium compounds CeIn (=Rh and Ir), which show competition between superconductivity and antiferromagnetism. The results suggest that the Ce~4 electrons in both compounds are nearly localized. We have found that although the Ce~4 electrons in the superconducting CeIrIn are more delocalized than those in the antiferromagnetic CeRhIn, their electronic structures are very similar to each other.

Study on colloids in the groundwater of Horonobe URL, 3; Interaction of rare earth elements and suspended matters contained in Horonobe deep groundwater

Kirishima, Akira*; Kuno, Atsushi*; Amamiya, Hiroki; Murakami, Hiroaki; Amano, Yuki; Iwatsuki, Teruki; Mizuno, Takashi; Kubota, Takumi*; Sasaki, Takayuki*; Sato, Nobuaki*

no journal, , 

no abstracts in English

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.

Geosphere stability project, 6; Chronological and chemical analyses of carbonate minerals

Watanabe, Takahiro; Kokubu, Yoko; Murakami, Hiroaki; Yokoyama, Tatsunori; Amamiya, Hiroki; Mizuno, Takashi; Kubota, Mitsuru; Iwatsuki, Teruki

no journal, , 

Chronological and geochemical studies of fracture filling calcite in rocks provide the information for changes in geochemical condition, such as redox potential and pH in geological environments. Because the calcite can be found as common filling minerals in the natural samples, age zoning and spatial distribution of chemical composition in the calcite could be a wide-use indicator to reconstruct the past environmental changes. Radiometric (U-Pb) dating in a micro scale area (less than 10 micrometer) on the filling mineral surface by laser ablation-inductively coupled plasm mass spectrometry system (LA-ICPMS) has been applied to geological samples. Additionally, past redox potential has been estimated by Fe contents in the carbonates, which is based on the distribution coefficient of Fe between calcite deposit and groundwater. In this study, we evaluated the possibility of in-situ radiometric dating for the filling minerals by LA-ICPMS and redox potential reconstruction by the theoretical calculation using the distribution coefficient.

Spin structural analyses using magnetic Bragg dips and edges

Mamiya, Hiroaki*; Oba, Yojiro; Terada, Noriki*; Watanabe, Norimichi*; Hiroi, Kosuke; Shinohara, Takenao; Oikawa, Kenichi

no journal, , 

no abstracts in English

Magnetic Bragg dip and Bragg edge in neutron transmission spectra of a typical spin order

Mamiya, Hiroaki*; Oba, Yojiro; Terada, Noriki*; Watanabe, Norimichi*; Hiroi, Kosuke; Shinohara, Takenao; Oikawa, Kenichi

no journal, , 

So far, neutron diffractometry has been a unique tool to clarify spin arrangements. However, it is not easy to measure the neutron diffraction under extreme sample environments such as high pressure and high magnetic field because such environments often require large equipments surrounding the samples and prevent the measurement of the scattered neutron. To overcome this issue, we focused on neutron transmission spectra, which includes the attenuation caused by the neutron diffraction. The neutron transmission spectra can be easily measured using only a transmission monitor without scattering detector. This presentation reports the first observation of the neutron transmission spectra generated by a typical spin order in nickel oxides. The results clearly show the neutron transmission spectroscopy is a promising tool for the study of the spin arrangements.

Short-range ordering of magnetic refrigerant materials Pd (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 HoPd(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 [0.18,0.18,0.18] developing at low temperatures. The short range correlation increases below 70K in TbPd(K).