Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

https://doi.org/10.3390/qubs1030009

The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.

Single-crystal neutron diffraction study of the heavy-electron superconductor CeNiGe

Ikeda, Yoichi*; Ueta, Daichi*; Yoshizawa, Hideki*; Nakao, Akiko*; Munakata, Koji*; Ohara, Takashi

Journal of the Physical Society of Japan, 84(12), p.123701_1 - 123701_5, 2015/12

https://doi.org/10.7566/JPSJ.84.123701

Single-crystal neutron diffraction study was performed for anomalous antiferromagnetic ordering in a heavy-electron superconductor CeNiGe. We observed incommensurate magnetic Bragg reflections characterized with the propagation vector of = (0; 0:41; 1=2) below the Nel temperature of 5 K, while there is no significant magnetic reflection at the commensurate propagation vector of = (1; 0; 0) at which another magnetic reflection was observed in the previous neutron diffraction study with a polycrystalline sample. From the single crystal study, we suggest that the magnetic phase of CeNiGe at ambient pressure is characterized only by the incommensurate propagation vector .

Temperature and composition phase diagram in the iron-based ladder compounds BaCsFeSe

Hawai, Takafumi*; Nambu, Yusuke*; Ogushi, Kenya*; Du, F.*; Hirata, Yasuyuki*; Avdeev, M.*; Uwatoko, Yoshiya; Sekine, Yurina; Fukazawa, Hiroshi; Ma, J.*; et al.

Physical Review B, 91(18), p.184416_1 - 184416_11, 2015/05

https://doi.org/10.1103/PhysRevB.91.184416

We investigated the iron-based ladder compounds (Ba, Cs)FeSe, whose parent compounds, BaFeSe and CsFeSe, have different space groups, formal valences of Fe and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, X-ray diffraction and powder neutron diffraction measurements were conducted to obtain the temperature and composition phase diagram of this system. Block magnetism seen in BaFeSe is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFeSe more resilient to Ba doping. Novel magnetic structure appears in intermediate compositions, which is similar to the stripe magnetism of CsFeSe but with different inter-ladder spin configuration. Intermediate compounds show insulating behavior, nevertheless finite T-linear contribution in specific heat was obtained at low temperature.

Unconventional ferroelectric transition in the multiferroic compound TbMnO revealed by the absence of an anomaly in -polarized phonon dispersion

Kajimoto, Ryoichi; Sagayama, Hajime*; Sasai, Kenzo*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Arima, Takahisa*; Hirota, Kazuma*; Mitsui, Yukari*; Yoshizawa, Hideki*; Baron, A. Q. R.*; et al.

Physical Review Letters, 102(24), p.247602_1 - 247602_4, 2009/06

https://doi.org/10.1103/PhysRevLett.102.247602

-dependence of spin exchange interactions in MnO ( = Rare-Earth Ions)

Kajimoto, Ryoichi; Mochizuki, Hidenori*; Yoshizawa, Hideki*; Shintani, Hiroshi*; Kimura, Tsuyoshi*; Tokura, Yoshinori*

Journal of the Physical Society of Japan, 74(9), p.2430 - 2433, 2005/09

https://doi.org/10.1143/JPSJ.74.2430

Magnon excitations have been investigated for PrMnO showing the -type antiferromagnetic ordering and TbMnO forming a long-period spin ordering by inelastic neutron scattering. Combined with a result of LaMnO [K.~Hirota ], the systematic data revealed that the ferromagnetic exchange interaction between nearest-neighbor (NN) Mn sites within the plane drastically decreases in MnO as the ionic radius of is reduced. In addition, finite next-nearest-neighbor (NNN) coupling is evident in TbMnO. In contrast, the exchange interaction along the axis shows much weaker dependence consistent with the Mn-O-Mn bond angle. These observations confirm a scenario that explains the evolution of spin structures in MnO in terms of the competition between the NN and NNN interactions [T.Kimura ].

Percolation fractal dimension in scattering line shapes of the random-field Ising model

Ye, F.*; Matsuda, Masaaki; Katano, Susumu; Yoshizawa, Hideki*; Belanger, D. P.*; Seppl, E. T.*; Fernandez-Baca, J. A.*; Alava, M. J.*

Journal of Magnetism and Magnetic Materials, 272-276, p.1298 - 1299, 2004/05

https://doi.org/10.1016/j.jmmm.2003.12.081

no abstracts in English

Neutron scattering study on NdB

Metoki, Naoto; Yamauchi, Hiroki; Matsuda, Masaaki*; Fernandez Baca, J.*; Yoshida, Masahiro*; Yoshizawa, Hideki*; Hagihara, Masato*; Watanuki, Ryuta*

no journal, , 

We report the magnetic structures and propose the mechanism of the successive transition based on the -electron state revealed by CEF excitation. We confirmed the non-collinear `all-in all-out' structure () of the in-plane moment. We found that the magnetic moment along the -axis showed diagonally antiferromagnetic structure (). The unusual magnetic ordering is phenomenologically understood via Landau theory. We also found that a long-period incommensurate modulation of the () antiferromagnetic structure of with the propagation = (0.14, 0.14, 0.1) and = (0.2, 0, 0.1) in phase III and IV, respectively. We found pseudo-quartet -electron state based on and . We can propose the intermediated phase as the magnetically ordered phase of while and coupling phase tabilized in low temperatures.

Inelastic X-ray scattering study of phonons in the multiferroic compound TbMnO

Kajimoto, Ryoichi; Sagayama, Hajime*; Sasai, Kenzo*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Arima, Takahisa*; Hirota, Kazuma*; Mitsui, Yukari*; Yoshizawa, Hideki*; Baron, A. Q. R.*; et al.

no journal, , 

Development of quasi-monoenergetic neutron standard calibration field of high energy range

Shikaze, Yoshiaki; Tanimura, Yoshihiko; Tsutsumi, Masahiro; Yoshizawa, Michio; Harano, Hideki*; Matsumoto, Tetsuro*; Mizuhashi, Kiyoshi

no journal, , 

no abstracts in English

Magnetic structure of TbMnO studied by spherical polarimetry

Kajimoto, Ryoichi; Matsuda, Masaaki; Takeda, Masayasu; Kakurai, Kazuhisa; Mitsui, Yukari*; Yoshizawa, Hideki*; Kimura, Tsuyoshi*; Tokura, Yoshinori*

no journal, , 

no abstracts in English