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論文

Magnetic, thermal, and neutron diffraction studies of a coordination polymer: bis(glycolato)cobalt(II)

中根 僚宏*; 米山 翔太*; 兒玉 健*; 菊地 耕一*; 中尾 朗子*; 大原 高志; 東中 隆二*; 松田 達磨*; 青木 勇二*; 藤田 渉*

Dalton Transactions, 48(1), p.333 - 338, 2019/01

 パーセンタイル:100(Chemistry, Inorganic & Nuclear)

The two-dimensional quadratic lattice magnet, bis(glycolato)cobalt(II) ([Co(HOCH$$_{2}$$CO$$_{2}$$)$$_{2}$$]), showed anti-ferromagnetic ordering at 15.0 K and an abrupt increase in magnetisation at H = 22 600 Oe and 2 K, thereby acting as a metamagnet. Neutron diffraction studies suggested that the magnetic moment vectors of the Co(II) ions had an amplitude of 3.59 mB and were not aligned in a fully antiparallel fashion to those of their neighbours, which caused canting between the magnetic moment vectors in the sheet. The canting angle was determined to be 7.1deg. Canting induced net magnetisation in the sheet, but this magnetisation was cancelled between sheets. The magnetisations in the sheets were oriented parallel to the magnetic field at the critical magnetic field.

論文

Transient ionization of the mesosphere during auroral breakup; Arase satellite and ground-based conjugate observations at Syowa Station

片岡 龍峰*; 西山 尚典*; 田中 良昌*; 門倉 昭*; 内田 ヘルベルト陽仁*; 海老原 祐輔*; 江尻 省*; 冨川 喜弘*; 堤 雅基*; 佐藤 薫*; et al.

Earth, Planets and Space (Internet), 71, p.9_1 - 9_10, 2019/01

 パーセンタイル:100(Geosciences, Multidisciplinary)

2017年6月30日22時21分から26分(世界時)にかけて、昭和基地にあるPANSYレーダーによってオーロラ爆発時の中間圏における過渡電離が観測された。通常、中間圏における過渡電離は100keV以上の高エネルギー電子が中間圏まで到達することにより引き起こされるが、同時間帯においてあらせ衛星が観測した100keV以上の電子フラックスは有意な上昇を示していなかった。このことから、本イベントは、10keV以下の低エネルギー電子が大量に熱圏に降り注ぐことにより発生したX線による電離であるとの仮説を立てた。この仮説の妥当性を検証するため、粒子・重イオン挙動解析コードPHITSを用いて様々なエネルギースペクトルを持つ電子が大気上空に進入した場合の電離分布を計算した。その結果、10keV以下の電子でも中間圏において十分な電離を引き起こすことが可能であることが分かり、仮説の妥当性が証明された。

論文

Unique helical magnetic order and field-induced phase in trillium lattice antiferromagnet EuPtSi

金子 耕士; Frontzek, M. D.*; 松田 雅昌*; 中尾 朗子*; 宗像 孝司*; 大原 高志; 垣花 将司*; 芳賀 芳範; 辺土 正人*; 仲間 隆男*; et al.

Journal of the Physical Society of Japan, 88, p.013702_1 - 013702_5, 2019/01

 被引用回数:1 パーセンタイル:14.05(Physics, Multidisciplinary)

Magnetic transitions in chiral antiferromagnet EuPtSi were investigated by means of single crystal neutron diffraction. In the ground state, magnetic peaks emerge at positions represented by $$q_{1}$$=$$(0.2, 0.3, 0)$$. Upon heating, an additional magnetic peak splitting around 2.5 K was uncovered, indicating a presence of a first-order transition with $$q^*_{1}$$=$$(0.2, 0.3, {delta})$$. An half-polarized neutron scattering for polarization parallel to Q reveled that polarization antiparallel to Q has stronger intensity in both magnetic phases. This feature clarifies single chiral character of helical structure with moments normal to the ordering vector in both ordered states. Under vertical magnetic field along [1,1,1] in the $$A$$ phase, magnetic peaks form hexagonal patterns in the equatorial scattering plane around nuclear. An ordering vector $$q_{A}$$ of the $$A$$-phase has the similar size in the periodicity to $$q_{1}$$, and could be a hallmark of a formation of skyrmion lattice in EuPtSi.

論文

Status of the neutron time-of-flight single-crystal diffraction data-processing software STARGazer

矢野 直峰*; 山田 太郎*; 細谷 孝明*; 大原 高志; 田中 伊知朗*; 新村 信雄*; 日下 勝弘*

Acta Crystallographica Section D; Structural Biology (Internet), 74(11), p.1041 - 1052, 2018/11

STARGazer is a data processing software for neutron time-of-flight (TOF) single-crystal diffraction data collected by the IBARAKI Biological Crystal Diffractometer (iBIX) at the Japan Proton Accelerator Research Complex (J-PARC). This software creates hkl intensity data from three-dimensional (x, y, TOF) diffraction data. STARGazer is composed of both a data processing component and a data visualization component. This article describes the status of data processing software STARGazer and its data processing algorithms.

論文

High oxide-ion conductivity in Si-deficient La$$_{9.565}$$(Si$$_{5.826}$$[]$$_{0.174}$$)O$$_{26}$$ apatite without interstitial oxygens due to the overbonded channel oxygens

藤井 孝太郎*; 八島 正知*; 日比野 圭祐*; 白岩 大裕*; 福田 功一郎*; 中山 享*; 石沢 伸夫*; 花島 隆泰*; 大原 高志

Journal of Materials Chemistry A, 6(23), p.10835 - 10846, 2018/06

 被引用回数:3 パーセンタイル:28.59(Chemistry, Physical)

Apatite-type rare earth silicates are attractive materials with exhaust application such as solid-oxide fuel cells, due to its extremely high oxide-ion conductivity below 600$$^{circ}$$C. Interstitial (excess) oxygens have been believed to be responsible for the high conductivity in apatite-type materials. On the contrary, the present study clearly reveals the presence of Si vacancies [] in La-rich La$$_{9.565}$$(Si$$_{5.826}$$[]]$$_{0.174}$$)O$$_{26}$$ instead of the interstitial oxygens, by single-crystal neutron and X-ray diffraction analyses, density measurements and ${{it ab initio}}$ electronic calculations.

論文

Magnetic-ordering propagation vectors of terbium hexaboride revisited

岩佐 和晃*; 伊賀 文俊*; 茂吉 武人*; 中尾 朗子*; 大原 高志

Journal of the Physical Society of Japan, 87(6), p.064705_1 - 064705_5, 2018/06

 パーセンタイル:100(Physics, Multidisciplinary)

The magnetic-ordered state of a single-crystal sample of TbB$$_{6}$$ has been studied with the high-precision neutron diffraction instrument SENJU installed at BL18 of the Materials and Life Science Facility in J-PARC. We observed new Bragg-reflection spots characterized by a propagation vector $$q_{rm M2}$$ = (1/4, 1/4, 0) below the N$'e$el temperature $$T_{rm N}$$ $$approx$$ 20 K, in addition to the $$q_{rm M1}$$ = (1/4, 1/4. 1/2) reported in the previous literatures. Because X-ray Thomson scattering measurements do not detect the $$q_{rm M2}$$ superlattice reflections at 13 K, $$q_{rm M2}$$ is a new magnetic-ordering propagation vector. The magnetic multi-q structure of TbB$$_{6}$$ is similar to that of CeB$$_{6}$$, whereas the ratio of the $$q_{rm M2}$$ amplitude to that of qM1 is smaller than in CeB$$_{6}$$. The combination of $$q_{rm M1}$$ and $$q_{rm M2}$$ is expected to assist the $$q_{rm L1}$$ = (1/2, 0, 0) lattice modulation.

論文

Structure analysis and derivation of deformed electron density distribution of polydiacetylene giant single crystal by the combination of X-ray and neutron diffraction data

田代 孝二*; 日下 勝弘*; 細谷 孝明*; 大原 高志; 塙坂 真*; 吉澤 功徳*; 山元 博子*; 新村 信雄*; 田中 伊知朗*; 栗原 和男*; et al.

Macromolecules, 51(11), p.3911 - 3922, 2018/06

 パーセンタイル:100(Polymer Science)

The crystal structure of polydiacetylene giant single crystal has been analyzed on the basis of the two different methods of wide-angle neutron diffraction and X-ray diffraction. The X-ray result gives us the total electron density distribution. The neutron result tells the positions of atomic nuclei. As a result, the so-called bonded (or deformed) electron density, i.e., the electron density distribution due to the conjugation among the covalently bonded atoms along the polymer chain, can be estimated using the two information. The present report is the first example of the application of X-N method to the synthetic polymer species.

論文

Mn$$_{2}$$VAl Heusler alloy thin films; Appearance of antiferromagnetism and exchange bias in a layered structure with Fe

土屋 朋生*; 小林 亮太*; 窪田 崇秀*; 斉藤 耕太郎*; 小野 寛太*; 大原 高志; 中尾 朗子*; 高梨 弘毅*

Journal of Physics D; Applied Physics, 51(6), p.065001_1 - 065001_7, 2018/02

 被引用回数:1 パーセンタイル:100(Physics, Applied)

Mn$$_{2}$$VAl Heusler alloy films were epitaxially grown on MgO(100) single-crystal substrates by ultra-high-vacuum magnetron sputtering. A2- and L21-type Mn$$_{2}$$VAl order was controlled by the deposition temperature. A2-type Mn$$_{2}$$VAl films showed no spontaneous magnetization, while L21-type Mn$$_{2}$$VAl films showed ferrimagnetic behaviour with a maximum saturation magnetization of 220 emu/cm$$^{3}$$ at room temperature (RT). An antiferromagnetic reflection was observed with neutron diffraction at RT for an A2-type Mn$$_{2}$$VAl film deposited at 400$$^{circ}$$C. A bilayer sample of the antiferromagnetic A2-type Mn$$_{2}$$VAl and Fe showed an exchange bias of 120 Oe at 10 K.

論文

Neutron scattering study of yttrium iron garnet

社本 真一; 伊藤 孝; 大西 弘明; 山内 宏樹; 稲村 泰弘; 松浦 直人*; 赤津 光洋*; 樹神 克明; 中尾 朗子*; 茂吉 武人*; et al.

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

 被引用回数:1 パーセンタイル:100(Materials Science, Multidisciplinary)

イットリウム鉄ガーネットの核および磁気構造と全マグノン分散を中性子散乱により調べた。低エネルギーの分散は強磁性マグノンで期待されるように14meVまで2次関数の分散を示した。$$q$$積分した動的磁化率$$chi$$"($$E$$)の虚部は低エネルギーで平方根のエネルギー依存性を示した。$$chi$$"($$E$$)から絶対値でマグノン状態密度を求めた。その値は理論的に予想されるマグノン分散でひとつのカラリティーモードに対応する。

論文

Inverse pole figure mapping of bulk crystalline grains in a polycrystalline steel plate by pulsed neutron Bragg-dip transmission imaging

佐藤 博隆*; 塩田 佳徳*; 諸岡 聡; 戸高 義一*; 足立 望*; 定松 直*; 及川 健一; 原田 正英; Zhang, S.*; Su, Y.; et al.

Journal of Applied Crystallography, 50(6), p.1601 - 1610, 2017/12

 被引用回数:5 パーセンタイル:20.86(Chemistry, Multidisciplinary)

A new mapping procedure for polycrystals using neutron Bragg-dip transmission is presented. This is expected to be useful as a new materials characterization tool which can simultaneously map the crystallographic direction of grains parallel to the incident beam. The method potentially has a higher spatial resolution than neutron diffraction imaging. As a demonstration, a Bragg-dip neutron transmission experiment was conducted at J-PARC on beamline MLF BL10 NOBORU. A large-grained Si-steel plate was used. Since this specimen included multiple grains along the neutron beam transmission path, it was a challenging task for existing methods to analyze the direction of the crystal lattice of each grain. A new data-analysis method for Bragg-dip transmission measurements was developed based on database matching. As a result, the number of grains and their crystallographic direction along the neutron transmission path have been determined.

論文

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

中島 健次; 川北 至信; 伊藤 晋一*; 阿部 淳*; 相澤 一也; 青木 裕之; 遠藤 仁*; 藤田 全基*; 舟越 賢一*; Gong, W.*; et al.

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

J-PARC物質・生命科学実験施設の中性子実験装置についてのレビューである。物質・生命科学実験施設には23の中性子ビームポートがあり21台の装置が設置されている。それらは、J-PARCの高性能な中性子源と最新の技術を組み合わせた世界屈指の実験装置群である。このレビューでは、装置性能や典型的な成果等について概観する。

論文

Quantum twin spectra in nanocrystalline silicon

松本 貴裕*; 大原 高志; 杉本 秀彦*; Bennington, S. M.*; 池田 進*

Physical Review Materials (Internet), 1(5), p.051601_1 - 051601_6, 2017/10

We identified twin split scattering spectra in hydrogen-terminated nanocrystalline silicon by using inelastic neutron scattering spectroscopy. A standard theoretical analysis based on the localized wave function of hydrogen in not sufficient to explain this duality. We show that this duality originates from the cooperative motion of hydrogen and silicon.

論文

Non-aqueous selective synthesis of orthosilicic acid and its oligomers

五十嵐 正安*; 松本 朋浩*; 八木橋 不二夫*; 山下 浩*; 大原 高志; 花島 隆泰*; 中尾 朗子*; 茂吉 武人*; 佐藤 一彦*; 島田 茂*

Nature Communications (Internet), 8, p.140_1 - 140_8, 2017/07

 被引用回数:2 パーセンタイル:70.98(Multidisciplinary Sciences)

Orthosilicic acid (Si(OH)$$_{4}$$) and its small condensation compounds are among the most important silicon compounds but have never been isolated, despite the long history of intense research due to their instability. These compounds would be highly useful building blocks for advanced materials if they become available at high purity. We developed a simple procedure to selectively synthesize orthosilicic acid, its dimer, cyclic trimer, and tetramer, as well as appropriate conditions to stabilize these species, in organic solvents. Isolation of orthosilicic acid, the dimer and the cyclic tetramer as hydrogen-bonded crystals with tetrabutylammonium halides and of the cyclic trimer as solvent-containing crystals was achieved. The solid-state structures of these compounds were unambiguously clarified by single crystal X-ray diffraction analysis and also by neutron diffraction study for orthosilicic acid. Based on these results, we also succeeded in developing a more practical synthetic procedure for high concentrations of stable orthosilicic acid stably in organic solvents via a simple hydrolysis of tetraalkoxysilanes.

論文

高速実験炉「常陽」の原子炉容器内観察・補修技術開発; 変形した実験装置の回収

芦田 貴志; 伊東 秀明; 宮本 一幸*; 中村 俊之; 古賀 和浩*; 大原 紀和*; 猪 博一*

日本原子力学会和文論文誌, 15(4), p.210 - 222, 2016/12

高速実験炉「常陽では、照射試験を終えた温度制御型材料照射装置(MARICO-2)の試料部を原子炉容器内から取り出すための作業が行われた。しかし、保持機構と試料部が完全に分離できていない状態で回転プラグを操作したことにより、試料部が炉内燃料貯蔵ラック上から突き出た状態で変形していることが炉内観察等の調査の結果確認された。また、突き出た試料部は、回転プラグに設置された炉心上部機構(UCS)の下面と干渉する高さにあり、UCSの下面を部分的に損傷させたことも確認された。UCSと試料部の干渉を避けるため、可動範囲を制限した結果、燃料交換機能が一部阻害された状態となった。復旧措置として、損傷したUCSの交換と変形した試料部の回収が決定され、試料部については、2007年12月に回収方法の検討に着手し、治具の設計・製作、モックアップ試験等の準備を経て、2014年6月11月に回収作業を実施した。回収した試料部は「常陽」に隣接する照射後試験施設において、各種試験に向けた照射試料の取り出し等が行われている。本件は、試料部の回収を通して得られたSFR炉内の遠隔補修技術の開発成果について、装置の設計・製作及び作業の実績を踏まえて報告するものである。

論文

Application of profile fitting method to neutron time-of-flight protein single crystal diffraction data collected at the iBIX

矢野 直峰*; 山田 太郎*; 細谷 孝明*; 大原 高志; 田中 伊知朗*; 日下 勝弘*

Scientific Reports (Internet), 6, p.36628_1 - 36628_9, 2016/12

 被引用回数:4 パーセンタイル:44.93(Multidisciplinary Sciences)

We developed and employed a profile fitting method for the peak integration of neutron time-of-flight diffraction data collected by the IBARAKI Biological Crystal Diffractometer (iBIX) at the Japan Proton Accelerator Research Complex (J-PARC) for protein ribonuclease A and alpha-thrombin single crystals. Gaussian convolved with two back-to-back exponentials was selected as the most suitable fitting function, and a profile fitting algorithm for the integration method was developed. It was clearly demonstrated that the profile fitting method provides more accurate integrated intensities and model structures than the summation integration method at higher resolution shells.

論文

Magnetic structure of divalent europium compound EuGa$$_{4}$$ studied by single-crystal time-of-flight neutron diffraction

川崎 卓郎; 金子 耕士; 仲村 愛*; 阿曽 尚文*; 辺土 正人*; 仲間 隆男*; 大原 高志; 鬼柳 亮嗣; 及川 健一; 田村 格良; et al.

Journal of the Physical Society of Japan, 85(11), p.114711_1 - 114711_5, 2016/11

 パーセンタイル:100(Physics, Multidisciplinary)

The magnetic structure of the intermetallic compound EuGa$$_{4}$$ was investigated using single-crystal neutron diffraction with TOF Laue technique on the new diffractometer SENJU at MLF of J-PARC. Despite of the high neutron absorption of Eu, a vast number of diffraction spots were observed without isotope enrichment. The magnetic reflections appeared at $$h + k + l$$ $$neq$$ 2$$n$$ below 16 K, indicating that the ordering vector is $$q$$ = (0, 0, 0). The continuous evolution of the magnetic reflection intensity below T$$_{N}$$ follows a squared Brillouin function for $$S$$ = 7/2. By adopting a wavelength-dependent absorption collection, the magnetic structure of EuGa$$_{4}$$ revealed that a nearly full magnetic moment of 6.4 $$mu$$B of Eu lies within the basal plane of the lattice.

論文

Molecular gyrotops with a five-membered heteroaromatic ring; Synthesis, temperature-dependent orientation of dipolar rotors inside the crystal, and its birefringence change

増田 敏幸*; Arase, Junko*; 稲垣 佑亮*; 川幡 正俊*; 山口 健太郎*; 大原 高志; 中尾 朗子*; 門馬 洋行*; Kwon, E.*; 瀬高 渉*

Crystal Growth & Design, 16(8), p.4392 - 4401, 2016/08

 被引用回数:13 パーセンタイル:9.6(Chemistry, Multidisciplinary)

Three-dimensional arrays of dipolar rotors were constructed as single crystals of molecular gyrotops, which are macrocage molecules with a bridged dipolar rotor. In this study, we synthesized novel molecular gyrotops with a five-membered heteroring, i.e., furan-diyl, thiophenediyl, and selenophene-diyl, and investigated the temperature-dependent orientation and rotation of the dipolar rotors inside the crystal.

論文

Encapsulating mobile proton carriers into structural defects in coordination polymer crystals; High anhydrous proton conduction and fuel cell application

犬飼 宗弘*; 堀毛 悟史*; 板倉 智也*; 篠崎 良太*; 荻原 直希*; 梅山 大樹*; Nagarker, S.*; 西山 裕介*; Malon, M.*; 林 灯*; et al.

Journal of the American Chemical Society, 138(27), p.8505 - 8511, 2016/07

 被引用回数:47 パーセンタイル:4.94(Chemistry, Multidisciplinary)

We describe encapsulation of mobile proton carriers into defect sites in non-porous coordination polymers. The proton carriers are encapasulated with high mobility and provide high proton conductivity at 150$$^{circ}$$C under anhydrous condition. The high proton conductivity and non-porous nature allow power generation by fuel cell in which CPs are used as electrolyte. To observe defects and mobile proton carriers, we carried out solid-state NMR, XAFS, XRD, and ICP-AES/EA. On the basis of these analyses, we elucidated that the defect sites provide space for mobile uncoordinated H$$_{3}$$PO$$_{4}$$, H$$_{2}$$PO$$_{4}$$$$^{-}$$, and H$$_{2}$$O. These mobile carriers play a key role to expand proton hopping path and promote the mobility of all protons in coordination frameworks, leading to high proton conductivity and fuel cell power generation.

論文

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

大原 高志; 鬼柳 亮嗣; 及川 健一; 金子 耕士; 川崎 卓郎; 田村 格良; 中尾 朗子*; 花島 隆泰*; 宗像 孝司*; 茂吉 武人*; et al.

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

 被引用回数:13 パーセンタイル:11.41(Chemistry, Multidisciplinary)

SENJU, a time-of-flight Laue-type single-crystal neutron diffractometer, was developed at the Materials and Life Science Experimental Facility (MLF) of the Japan Accelerator Research Complex (J-PARC). Molecular structure analysis of a sub-millimeter taurine crystal and magnetic structure analysis of a MnF$$_{2}$$ crystal were performed to evaluate its performance.

論文

Preparation and evaluation of an astatine-211-labeled sigma receptor ligand for $$alpha$$ radionuclide therapy

小川 数馬*; 水野 覚瑛*; 鷲山 幸信*; 柴 和弘*; 高橋 成人*; 小阪 孝史*; 渡辺 茂樹; 篠原 厚*; 小谷 明*

Nuclear Medicine and Biology, 42(11), p.875 - 879, 2015/11

 被引用回数:9 パーセンタイル:34.43(Radiology, Nuclear Medicine & Medical Imaging)

Sigma receptors are overexpressed in a variety of human tumors, making them potential targets for radionuclide receptor therapy. We have previously synthesized and evaluated $$^{131}$$I-labeled (+)-2-[4-(4-iodophenyl)piperidino]cyclohexanol [(+)-[$$^{131}$$I]pIV], which has a high affinity for sigma receptors. Therefore, (+)-[$$^{131}$$I]pIV significantly inhibited tumor cell proliferation in tumor-bearing mice. In the present study, we report the synthesis and the in vitro and in vivo characterization of (+)-[$$^{211}$$At]pAtV, an $$^{211}$$At-labeled sigma receptor ligand, that has potential use in $$alpha$$-radionuclide receptor therapy. The lipophilicity of (+)-[$$^{211}$$At]pAtV was similar to that of (+)-[$$^{125}$$I]-pIV. Uptake of DU-145, prostate cancer cell lines, and the biodistribution patterns in DU-145 tumor-bearing mice at 1 h post-injection were also similar between (+)-[$$^{211}$$At]pAtV and (+)-[$$^{125}$$I]-pIV. Namely, (+)-[$$^{211}$$At]pAtV demonstrated high uptake and retention in tumor via binding to sigma receptors.

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