Sinusoidal magnetic structure of andalusite-type AlxFe-xGeO with = 0.09 and 0.15

Kakimoto, Kazuo*; Ota, Hiroto*; Haraguchi, Yuya*; Hagihara, Masato; Torii, Shuki*; Kamiyama, Takashi*; Katori, Hiroko*

Journal of the Physical Society of Japan, 91(5), p.054707_1 - 054707_9, 2022/05

https://doi.org/10.7566/JPSJ.91.054707

Origin of magnetovolume effect in a cobaltite

Miao, P.*; Tan, Z.*; Lee, S. H.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Yonemura, Masao*; Koda, Akihiro*; Komatsu, Kazuki*; Machida, Shinichi*; Sano, Asami; et al.

Physical Review B, 103(9), p.094302_1 - 094302_18, 2021/03

https://doi.org/10.1103/PhysRevB.103.094302

The layered perovskite PrBaCoO demonstrates a strong negative thermal expansion (NTE) which holds potential for being fabricated into composites with zero thermal expansion. The NTE was found to be intimately associated with the spontaneous magnetic ordering, known as magneto-volume effect (MVE). Here we report with compelling evidences that the continuous-like MVE in PrBaCoO is intrinsically of discontinuous character, originating from an magnetoelectric transition from an antiferromagnetic insulating large-volume (AFILV) phase to a ferromagnetic less-insulating small-volume (FLISV) phase. Furthermore, the magnetoelectric effect (ME) shows high sensitivity to multiple external stimuli such as temperature, carrier doping, hydrostatic pressure, magnetic field etc. In contrast to the well-known ME such as colossal magnetoresistance and multi-ferroic effect which involve symmetry breaking of crystal structure, the ME in the cobaltite is purely isostructural. Our discovery provides a new path way to realizing the ME as well as the NTE, which may find applications in new techniques.

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.

First neutron production utilizing J-PARC pulsed spallation neutron source JSNS and neutronic performance demonstrated

Maekawa, Fujio; Harada, Masahide; Oikawa, Kenichi; Teshigawara, Makoto; Kai, Tetsuya; Meigo, Shinichiro; Oi, Motoki; Sakamoto, Shinichi; Takada, Hiroshi; Futakawa, Masatoshi; et al.

Nuclear Instruments and Methods in Physics Research A, 620(2-3), p.159 - 165, 2010/08

https://doi.org/10.1016/j.nima.2010.04.020

The J-PARC 1-MW pulsed spallation neutron source JSNS was successfully launched on 30th of May 2008. To demonstrate the unique features of the moderator design and the neutronic performance of JSNS the neutron spectral intensity, absolute neutron flux, and time structure of the neutron pulse shapes etc have been measured using several neutron instruments since then. The measured energy spectra clearly revealed the feature of the para-hydrogen, as expected when designing the moderator. The measured neutron flux below 0.4 eV agreed with the corresponding design value within 20%, thus suggesting that the JSNS design calculations to have been reliable. World-class high-resolution diffraction data could be recorded due to the suitability of design of the moderators and the instruments. Another world-class high-intensity neutron flux was also capable of being demonstrated due to the unique design of the large cylindrical coupled moderator.

The Ibaraki prefecture materials design diffractometer for J-PARC; Designing neutron guide

Harjo, S.; Kamiyama, Takashi*; Torii, Shuki; Ishigaki, Toru; Yonemura, Masao*

Physica B; Condensed Matter, 385-386(Part 2), p.1025 - 1028, 2006/11

https://doi.org/10.1016/j.physb.2006.05.327

Ibaraki Prefecture Materials Design Diffractometer of J-PARC is a time-of-flight neutron powder diffractometer with the resolution as good as / = 0.16 % (almost constant value) for (L1 of 26.5 m). Since this diffractometer has many detectors covering wide 2 range, measurements with wide range, , i.e., PDF analysis and small angle scattering can also be performed. Designing of neutron guide is therefore very important to enhance the performances mentioned above without sacrificing beam intensity. Non-parallel guides including elliptical ones have been compared with a linear-straight guide using the McStas simulation. The elliptical guide having the exit focal points away behind the sample position is available to increase the neutron flux at the sample but give a slight lowering of the instrumental resolution. This elliptical guide gives also Garland peaks at short wavelengths that may give large ambiguities in powder diffraction measurements. Therefore, the linear-straight guide is considered as the best choice for this instrument to keep a good resolution and also a relatively high flux.

The Design of the radial collimator for residual stress analysis diffractometer at J-PARC

Torii, Shuki; Moriai, Atsushi

JAEA-Technology 2005-004, 31 Pages, 2006/02

JAEA-Technology-2005-004.pdf:13.06MB

no abstracts in English

Current status of sample environment in MLF J-PARC

Kawamura, Seiko; Kambara, Wataru; Yamauchi, Yasuhiro; Yokoo, Tetsuya*; Munakata, Koji*; Kawakita, Yukinobu; Nakatani, Takeshi; Torii, Shuki*; Kajimoto, Ryoichi*; Nakajima, Kenji; et al.

no journal, , 

Current status and plans of sample environment (SE) in MLF are introduced and discussed in the presentation. As a new SE device, a 7 T vertical-field superconducting magnet was install in March 2012, and is scheduled to be used for a general user's experiment coming October. Pulse magnet system for neutron experiments has also been developed in IMR group in Tohoku Univ., and 40 T of pulsed magnetic field has successfully applied in a neutron experiment in our facility. Furthermore, we have planned effective use of SE resources of the KEK neutron facility (KENS), which was shutdown in 2006, and we completed transportation of them from Tsukuba to MLF in FY2011, One of remaining issues is user support system on SE.

Current status and future plan of the software framework in MLF computing environment

Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi; Kajimoto, Ryoichi; Harjo, S.; Arai, Masatoshi; Ohara, Takashi; Nakagawa, Hiroshi; Aoyagi, Tetsuo; Otomo, Toshiya*; et al.

no journal, , 

We have developed the software framework in MLF computing environment from 2006 to 2008. The software framework is the fundamental software for neutron and muon experimental instruments in J-PARC/MLF. Currently, the software framework is installed at 4D Space Access Neutron Spectrometer (BL01), IBARAKI Biological Crystal Diffractometer (BL03), Cold-Neutron Disk-Chopper Spectrometer (BL14), Engineering Materials Diffractometer (BL19) and High Intensity Total Diffractometer (BL21). The features of experimental control, analysis, visualization and authorization are already implemented in the software framework. In this year, we will start the development to introduce the feature of database. We will present the current status and future plan of the software framework.

Field dependence of coupled sawtooth chain magnet Mn(OH)X (X = Cl, Br)

Hagihara, Masato; Torii, Shuki*

no journal, , 

no abstracts in English

Current status and future plan of sample environment in MLF, J-PARC

Kawamura, Seiko; Yokoo, Tetsuya*; Kambara, Wataru; Munakata, Koji*; Kajimoto, Ryoichi*; Nakatani, Takeshi; Kaneko, Koji; Kawakita, Yukinobu; Takata, Shinichi; Nakajima, Kenji; et al.

no journal, , 

In large user facilities such as neutron experimental facilities, sample environment (SE) is one of the most important factors to yield high-quality output. In the Materials and Life Science Experimental Facility (MLF) in J-PARC, various neutron experiments have been performed in wide range of scientific researches and industrial applications, and the number and variety of proposals will further increase after resuming operation of J-PARC. At the beginning stage, the SE team in MLF has discussed SE standardization, to save the cost and manpower, to make compatibility among instruments, and to increase the experimental efficiency by sharing the SE devices and techniques for operation. Recently we started preparation of "SE area" in the experimental hall, where we can do maintenance of equipments, pre-cooling of cryostats and so on. The SE team is now discussing future plan including user support system.