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

A SANS study on perpendicular magnetic recording hard disk media

Hagiya, Hiroyuki; Oku, Takayuki; Kira, Hiroshi; Shinohara, Takenao; Suzuki, Junichi; Takeda, Masayasu; Kakurai, Kazuhisa; Yokoyama, Makoto*; Nishihara, Yoshikazu*; Oba, Yojiro*; et al.

no journal, , 

no abstracts in English

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.

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).