Neutron scattering study of yttrium iron garnet

Shamoto, Shinichi; Ito, Takashi; Onishi, Hiroaki; Yamauchi, Hiroki; Inamura, Yasuhiro; Matsuura, Masato*; Akatsu, Mitsuhiro*; Kodama, Katsuaki; Nakao, Akiko*; Moyoshi, Taketo*; et al.

Physical Review B, 97(5), p.054429_1 - 054429_9, 2018/02

https://doi.org/10.1103/PhysRevB.97.054429

Nuclear and magnetic structure and full magnon dispersions of yttrium iron garnet YFeO have been studied by neutron scattering. The lowest-energy dispersion below 14 meV exhibits a quadratic dispersion as expected from ferromagnetic magnons. The imaginary part of -integrated dynamical spin susceptibility "() exhibits a square-root energy-dependence in the low energies. The magnon density of state is estimated from the "() obtained on an absolute scale. The value is consistent with a single chirality mode for the magnon branch expected theoretically.

SENJU; A New time-of-flight single-crystal neutron diffractometer at J-PARC

Ohara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Kaneko, Koji; Kawasaki, Takuro; Tamura, Itaru; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Moyoshi, Taketo*; et al.

Journal of Applied Crystallography, 49(1), p.120 - 127, 2016/02

https://doi.org/10.1107/S1600576715022943

Search for magnetic excitation spectra of NaCoODO; Neutron scattering

Moyoshi, Taketo*; Yasui, Yukio*; Soda, Minoru*; Kobayashi, Yoshiaki*; Sato, Masatoshi*; Kakurai, Kazuhisa

Journal of the Physical Society of Japan, 75(7), p.074705_1 - 074705_6, 2006/07

https://doi.org/10.1143/JPSJ.75.074705

Neutron scattering investigations on single crystal NaCoO y(DO) have been carried out. Strong 2-D diffuse scattering due to the short-range ordered state of DO molecules are observed. Significant scattering has been also observed for phonons originating from the vibrations of the short-range ordered DO molecules. No firm evidence for the magnetic fluctuations has been found for the hydrated superconducting component NaCoO y(DO), while the very weak intensity modulation observed in the scans along (1/2,1/2,l) suggests the existence of the antiferromagnetic fluctuations in the non-hydrated parts of the sample.

Magnetic structure study of SmBaMnO by neutron magnetic diffraction

Kiyanagi, Ryoji; Yamada, Shigeki*; Aoki, Hiroshi*; Sagayama, Hajime*; Moyoshi, Taketo*; Nakao, Akiko*; Arima, Takahisa*

no journal, , 

The materials represented as ReBaMnO, with an A-site ordered double perovskite structure, exhibit variety of physical orders owing to the competition between charges, orbitals and spins. SmBaMnO shows a charge-orbital order at 380K, a charge-orbital re-arrangement and an antiferromagnetic transition around 200K. In this study, the magnetic structure in the antiferromagnetic phase and the relation between the charge-orbital re-arrangent and the antiferromagnetic phase were investigated by means of neutron magnetic scattering. The measurements were performed on the single crystal neutron diffractometer, SENJU, at J-PARC/MLF. The diffraction pattern revealed magnetic reflections arising from the antiferromagnetic order, which is consistent with the ordering patterns of the charge and the orbitals. The temperature dependences of superlattice reflections and the magnetic reflections clarified that the antiferromagnetic phase transition was triggered by the charge-orbital re-arrangement.

Specs of special environment neutron single crystal diffractometer SENJU

Kiyanagi, Ryoji; Ohara, Takashi; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Moyoshi, Taketo*; Kuroda, Tetsuya*; Tamura, Itaru; Oikawa, Kenichi; Kaneko, Koji; et al.

no journal, , 

SENJU is a TOF-Laue type neutron single crystal diffractometer built at BL18 in J-PARC/MLF and has been in operation since 2012. This instrument is designed to perform precise structure analyses of inorganic materials, small molecular materials and magnetic materials under special environment. With this instrument, highly efficient measurements of a small single crystal can be achieved utilizing the high flux white neutrons provided by J-PARC and multiple 2-dimentional detectors. 4K-cryostat is one of the most commonly used sample environment devices which is equipped with a 2-axis rotators at the cold head. Owing to this functionality, one can measure several different orientations of a sample without moving the cryostat nor without taking the sample out. The superconducting magnet which can generate 7T at most offers very clean data since no Bragg reflections originated from the magnet appear in the low-momentum transfer region. The measured data will be analyzed with a software called STARGazer, which can cover the visualization of the data, data reduction to histogram files, determination of the orientation matrixes and integration of peak intensity for further structure analyses.

Latest status of SENJU, a TOF single crystal neutron diffractometer

Ohara, Takashi; Kiyanagi, Ryoji; Nakao, Akiko*; Munakata, Koji*; Moyoshi, Taketo*; Moriyama, Kentaro*

no journal, , 

no abstracts in English

Study of 2-(2'-hydroxyphenyl)benzimidazole by single crystal neutron diffraction at SENJU

Ohara, Takashi; Kiyanagi, Ryoji; Hanashima, Takayasu*; Moyoshi, Taketo*; Nakao, Akiko*; Munakata, Koji*; Kuroda, Tetsuya*

no journal, , 

no abstracts in English

Recent advances of a single crystal neutron diffractometer SENJU at J-PARC

Ohara, Takashi; Kiyanagi, Ryoji; Nakao, Akiko*; Munakata, Koji*; Moyoshi, Taketo*; Moriyama, Kentaro*; Hanashima, Takayasu*; Kuroda, Tetsuya*

no journal, , 

The Superconductivity and magnetism of the hydrate of NaCoO

Moyoshi, Taketo*; Yokoi, Mai*; Soda, Minoru*; Yasui, Yukio*; Kobayashi, Yoshiaki*; Sato, Masatoshi*; Igawa, Naoki; Kakurai, Kazuhisa

no journal, , 

no abstracts in English

Contrasting magnetic ground state in isoelectronic compound Eu ( = Al, Ga)

Kaneko, Koji; Kawasaki, Takuro; Nakamura, Ai*; Moyoshi, Taketo*; Munakata, Koji*; Nakao, Akiko*; Hanashima, Takayasu*; Kiyanagi, Ryoji; Ohara, Takashi; Oikawa, Kenichi; et al.

no journal, ,