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阿部 伸行*; 塩澤 俊介*; 松浦 慧介*; 佐賀山 基*; 中尾 朗子*; 大原 高志; 徳永 祐介*; 有馬 孝尚*
Physical Review B, 101(18), p.180407_1 - 180407_5, 2020/05
被引用回数:0 パーセンタイル:100(Materials Science, Multidisciplinary)The correlation between magnetism and electric polarization in a chiral insulating magnet BaFe
O
Cl
has been investigated. The temperature dependence of magnetic susceptibility shows an anomaly at 564 K, suggesting the onset of antiferromagnetic order of Fe
moments. Electric polarization appears in a magnetic field below TN due to the spin-direction-dependent metal-ligand hybridization. The direction of the electric polarization can be controlled in three-dimensional space by changing the direction of an external magnetic field. This compound also shows an antiferromagnetic-to-weak-ferromagnetic transition accompanied by a structural phase transition at 140 K.
中里 晟也*; 岩佐 和晃*; 橋本 大輔*; 塩澤 真未*; 桑原 慶太郎*; 中尾 裕則*; 佐賀山 基*; 石角 元志*; 大原 高志; 中尾 朗子*; et al.
JPS Conference Proceedings (Internet), 30, p.011128_1 - 011128_6, 2020/03
Successive phase transitions of Ir
Sn
(
: La and Ce) were studied using neutron and X-ray diffraction techniques. A semimetal Ce
Ir
Sn
undergoes three phase transitions: an antiferromagnetic ordering characterized by a propagation vector
= (1/2, 1/2, 2/5) below 0.6 K, a structural transformation with
= (1/4, 1/4, 1/4) at 2.0 K, and another structural transformation with
= (1/2, 1/2, 0) above room temperature. La
Ir
Sn
was confirmed to be a superconductor below 2.5 K under the
= (1/2, 1/2, 0) structure that also appears above room temperature.
駒淵 舞*; 漆原 大典*; 浅香 透*; 福田 功一郎*; 大原 高志; 宗像 孝司*; 石川 喜久*
Journal of the Physical Society of Japan, 89(3), p.034601_1 - 034601_5, 2020/03
被引用回数:0 パーセンタイル:100(Physics, Multidisciplinary)The crystal structure of an X-type hexaferrite SrCo
Fe
O
was investigated by the X-ray and neutron diffraction methods for a single crystal. Sr
Co
Fe
O
has the crystal structure described as a space group
(
) and its lattice constants are
= 5.9165(2)
; and
= 84.1395(33)
; at 843 K. Co ions are almost localized in the octahedral site (
) in the middle of S
S
blocks. In addition, the adjacent octahedral and tetrahedral sites to
site contain the significant number of Co
.
池田 修悟*; 金子 耕士; 田中 佑季*; 川崎 卓郎; 花島 隆泰*; 宗像 孝司*; 中尾 朗子*; 鬼柳 亮嗣; 大原 高志; 望月 健生*; et al.
Journal of the Physical Society of Japan, 89(1), p.014707_1 - 014707_7, 2020/01
被引用回数:0 パーセンタイル:100(Physics, Multidisciplinary)Magnetism in EuNiIn has been studied by specific heat, magnetic susceptibility, magnetization,
Eu M
ssbauer spectroscopy, and neutron diffraction experiments. The specific heat shows two magnetic transitions at
and
at zero magnetic field. An antiferromagnetic ground state of EuNiIn
has a uniaxial magnetic anisotropy along the b-axis, revealed by the magnetic susceptibility and the M
ssbauer spectroscopy. Single crystal neutron diffraction experiments clarify that this antiferromagnetic structure in the ground state is characterized by the commensurate propagation vector
= (1/2, 1/2, 1/2) which reveals no distinct anomaly at
. The magnetization curve along the b-axis at 2 K shows four successive magnetic field-induced transitions up to 50 kOe and, reaches 7
/f.u. above 190 kOe, The magnetic phase diagram in EuNiIn
has unique characteristics with five magnetic states in low magnetic field.
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 (Internet), 48(1), p.333 - 338, 2019/01
被引用回数:1 パーセンタイル:81.59(Chemistry, Inorganic & Nuclear)The two-dimensional quadratic lattice magnet, bis(glycolato)cobalt(II) ([Co(HOCHCO
)
]), 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.
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:20 パーセンタイル:5.72(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 =
. Upon heating, an additional magnetic peak splitting around 2.5 K was uncovered, indicating a presence of a first-order transition with
=
. 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
phase, magnetic peaks form hexagonal patterns in the equatorial scattering plane around nuclear. An ordering vector
of the
-phase has the similar size in the periodicity to
, and could be a hallmark of a formation of skyrmion lattice in EuPtSi.
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
被引用回数:7 パーセンタイル:29(Biochemical Research Methods)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.
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:11 パーセンタイル:32.69(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 600C. 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
(Si
[]]
)O
instead of the interstitial oxygens, by single-crystal neutron and X-ray diffraction analyses, density measurements and
electronic calculations.
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
被引用回数:0 パーセンタイル:100(Physics, Multidisciplinary)The magnetic-ordered state of a single-crystal sample of TbB 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
= (1/4, 1/4, 0) below the N
el temperature
20 K, in addition to the
= (1/4, 1/4. 1/2) reported in the previous literatures. Because X-ray Thomson scattering measurements do not detect the
superlattice reflections at 13 K,
is a new magnetic-ordering propagation vector. The magnetic multi-q structure of TbB
is similar to that of CeB
, whereas the ratio of the
amplitude to that of qM1 is smaller than in CeB
. The combination of
and
is expected to assist the
= (1/2, 0, 0) lattice modulation.
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
被引用回数:2 パーセンタイル:84.06(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.
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:2 パーセンタイル:79.06(Physics, Applied)MnVAl Heusler alloy films were epitaxially grown on MgO(100) single-crystal substrates by ultra-high-vacuum magnetron sputtering. A2- and L21-type Mn
VAl order was controlled by the deposition temperature. A2-type Mn
VAl films showed no spontaneous magnetization, while L21-type Mn
VAl films showed ferrimagnetic behaviour with a maximum saturation magnetization of 220 emu/cm
at room temperature (RT). An antiferromagnetic reflection was observed with neutron diffraction at RT for an A2-type Mn
VAl film deposited at 400
C. A bilayer sample of the antiferromagnetic A2-type Mn
VAl and Fe showed an exchange bias of 120 Oe at 10 K.
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:8 パーセンタイル:36.23(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。積分した動的磁化率
"(
)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。
"(
)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。
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。
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
被引用回数:0 パーセンタイル:100(Materials Science, Multidisciplinary)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.
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:7 パーセンタイル:67.88(Multidisciplinary Sciences)Orthosilicic acid (Si(OH)) 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.
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:10 パーセンタイル:29.13(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.
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
被引用回数:4 パーセンタイル:55.85(Physics, Multidisciplinary)The magnetic structure of the intermetallic compound EuGa 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
2
below 16 K, indicating that the ordering vector is
= (0, 0, 0). The continuous evolution of the magnetic reflection intensity below T
follows a squared Brillouin function for
= 7/2. By adopting a wavelength-dependent absorption collection, the magnetic structure of EuGa
revealed that a nearly full magnetic moment of 6.4
B of Eu lies within the basal plane of the lattice.
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:22 パーセンタイル:10.33(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.
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:82 パーセンタイル:4.89(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 150C 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
PO
, H
PO
, and H
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.
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:26 パーセンタイル:6.18(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 crystal were performed to evaluate its performance.