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論文

Programmable synthesis of silver wheels

Kwon, H.*; Pietrasiak, E.*; 大原 高志; 中尾 朗子*; Chae, B.*; Hwang, C.-C.*; Jung, D.*; Hwang, I.-C.*; Ko, Y. H.*; Kim, K.*; et al.

Inorganic Chemistry, 60(9), p.6403 - 6409, 2021/05

 被引用回数:0 パーセンタイル:0.01(Chemistry, Inorganic & Nuclear)

The synthesis of sandwich-shaped multinuclear silver complexes with planar penta- and tetranuclear wheel-shaped silver units and a central anion is reported, along with complete spectroscopic and structural characterization. An NMR mechanistic study reveals that silver complexes were formed in the following order: 2Ag $$rightarrow$$ 3Ag$$^{rm H2O}$$ $$rightarrow$$ 5Ag$$^{rm OH}$$ $$rightarrow$$ 4Ag$$^{rm OH}$$. The central hydroxides in 4Ag$$^{rm OH}$$ and 5Ag$$^{rm OH}$$ exhibit exotic physical properties due to the confined environment inside the complex. The size of these silver wheels can be tuned by changing the central anion or extracting/adding one silver atom. This study provides the facile way to synthesize discrete wheel-shaped multinuclear silver complexes and provides valuable insights into the dynamics of the self-assembly process.

論文

Correlated Li-ion migration in the superionic conductor Li$$_{10}$$GeP$$_{2}$$S$$_{12}$$

矢島 健*; 日沼 洋陽*; 堀 智*; 岩崎 類*; 菅野 了次*; 大原 高志; 中尾 朗子*; 宗像 孝司*; 広井 善二*

Journal of Materials Chemistry A, 9(18), p.11278 - 11284, 2021/05

 被引用回数:1 パーセンタイル:0(Chemistry, Physical)

Herein, we studied the crystalline compound Li$$_{10}$$GeP$$_{2}$$S$$_{12}$$ with the largest Li-ion conductivity thus far via a novel route based on a combination of single-crystal neutron diffraction experiments at low temperature and first-principles calculations, and found that a correlated migration of the densely packed Li ions governs the overall Li-ion conduction. The correlated migration mechanism provides us with guidelines on how to design efficient superionic conductors for more efficient batteries.

論文

Magnetically induced electric polarization in Ba$$_{3}$$Fe$$_{2}$$O$$_{5}$$Cl$$_{2}$$ with tunable direction in three dimensions

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:0(Materials Science, Multidisciplinary)

The correlation between magnetism and electric polarization in a chiral insulating magnet Ba$$_{3}$$Fe$$_{2}$$O$$_{5}$$Cl$$_{2}$$ has been investigated. The temperature dependence of magnetic susceptibility shows an anomaly at 564 K, suggesting the onset of antiferromagnetic order of Fe$$^{3+}$$ 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.

論文

Successive phase transitions in $$R_{3}$$Ir$$_{4}$$Sn$$_{13}$$ ($$R$$: La and Ce) investigated using neutron and X-ray diffraction

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 $$R_{3}$$Ir$$_{4}$$Sn$$_{13}$$ ($$R$$: La and Ce) were studied using neutron and X-ray diffraction techniques. A semimetal Ce$$_{3}$$Ir$$_{4}$$Sn$$_{13}$$ undergoes three phase transitions: an antiferromagnetic ordering characterized by a propagation vector $$q_{rm M}$$ = (1/2, 1/2, 2/5) below 0.6 K, a structural transformation with $$q_{rm S2}$$= (1/4, 1/4, 1/4) at 2.0 K, and another structural transformation with $$q_{rm S1}$$ = (1/2, 1/2, 0) above room temperature. La$$_{3}$$Ir$$_{4}$$Sn$$_{13}$$ was confirmed to be a superconductor below 2.5 K under the $$q_{rm S1}$$ = (1/2, 1/2, 0) structure that also appears above room temperature.

論文

Crystal structure and cation distribution of the X-type hexaferrite Sr$$_{2}$$Co$$_{2}$$Fe$$_{28}$$O$$_{46}$$

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:0(Physics, Multidisciplinary)

The crystal structure of an X-type hexaferrite Sr$$_{2}$$Co$$_{2}$$Fe$$_{28}$$O$$_{46}$$ was investigated by the X-ray and neutron diffraction methods for a single crystal. Sr$$_{2}$$Co$$_{2}$$Fe$$_{28}$$O$$_{46}$$ has the crystal structure described as a space group $$Roverline{3}m$$ ($$Z = 3$$) and its lattice constants are $$a$$ = 5.9165(2) ${AA}$; and $$c$$ = 84.1395(33) ${AA}$; at 843 K. Co ions are almost localized in the octahedral site ($$9d$$) in the middle of S$$^{*}$$S$$^{*}$$ blocks. In addition, the adjacent octahedral and tetrahedral sites to $$9d$$ site contain the significant number of Co$$^{2+}$$.

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

 被引用回数:1 パーセンタイル:11.81(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

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:12 パーセンタイル:61.53(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

 被引用回数:0 パーセンタイル:0(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

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:11 パーセンタイル:47.4(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

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:24 パーセンタイル:90.91(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

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:33 パーセンタイル:94.36(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

Single-crystal neutron diffraction study of the heavy-electron superconductor CeNiGe$$_{3}$$

池田 陽一*; 植田 大地*; 吉澤 英樹*; 中尾 朗子*; 宗像 孝司*; 大原 高志

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

 被引用回数:2 パーセンタイル:24.12(Physics, Multidisciplinary)

特異な反強磁性秩序化を示すことが知られているheavy-electron超伝導体であるCeNiGe$$_{3}$$について、MLFのSENJUを用いて単結晶中性子回折測定を行った。相転移温度の5K以下で測定を行ったところ、以前の粉末試料を用いた回折測定では伝搬ベクトルとして$$k_{1}$$=(1,0,0)と$$k_{2}$$=(0,0.41,1/2)が観測されたのに対して、単結晶試料を用いた測定では$$k_{2}$$=(0,0.41,1/2)のみが観測された。このことから、CeNiGe$$_{3}$$の常圧における磁気特性は伝搬ベクトル$$k_{2}$$のみによって特徴づけられることが示唆された。

論文

Proton order-disorder phenomena in a hydrogen-bonded rhodium-$$eta$$$$^{5}$$-semiquinone complex; A Possible dielectric response mechanism

満身 稔*; 江崎 一成*; 小松 裕貴*; 鳥海 幸四郎*; 宮東 達也*; 水野 元裕*; 東 信晃*; 宮崎 裕司*; 中野 元裕*; 北河 康隆*; et al.

Chemistry; A European Journal, 21(27), p.9682 - 9696, 2015/06

 被引用回数:6 パーセンタイル:26.76(Chemistry, Multidisciplinary)

A newly synthesized one-dimensional (1D) hydrogen-bonded (H-bonded) rhodium(II)-$$eta$$$$^{5}$$-semiquinone complex, [Cp$$^{*}$$Rh($$eta$$$$^{5}$$-$$p$$-HSQ-Me$$_{4}$$)]PF$$_{6}$$ exhibits a paraelectric-;antiferroelectric second-order phase transition at 237.1 K. Neutron and X-ray crystal structure analyses reveal that the H-bonded proton is disordered over two sites in the room-temperature (RT) phase. The phase transition would arise from this proton disorder together with rotation or libration of the Cp$$^{*}$$ ring and PF$$_{6}$$ ion. The relative permittivity $$varepsilon$$$$_{b}$$' along the H-bonded chains reaches relatively high values (ca., 130) in the RT phase.

論文

J-PARCにおけるパルス中性子ビームの利用と展望,1; 中性子ビームの特徴と結晶構造解析

阿久津 和宏*; 大原 高志

ぶんせき, 2014(11), p.617 - 621, 2014/11

J-PARCのMLFでは現在18本の中性子ビームラインに実験装置が設置され、世界最高強度のパルス中性子ビームを用いた学術研究や産業利用が行われている。本稿では、J-PARCおよびMLFの中性子実験施設の概要、中性子の特徴を紹介するとともに、中性子実験装置の一つである単結晶回折計「千手」の特徴に触れながら中性子結晶構造解析について説明する。

口頭

Phase transition and internal crystal structure of superprotonic conductor, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$

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

no journal, , 

M$$_{3}$$H(XO$$_{4}$$)$$_{2}$$(M=アルカリ金属、X=Se, S)で表わされる一連の物質群は比較的低温において高いプロトン伝導性を示すことが知られており、低い温度でも動作可能な電池やセンサーなどの応用材料として注目を集めている。高いプロトン伝導性は構造相転移とともに発現するが、その相転移温度はMやXの元素種によって変化する。本研究では元素種の変化によりなぜ相転移温度が変化するのかを明らかにするため、Mの元素としてRbとKを入れた物質を対象として相転移温度と内部構造の変化の関係を調べた。伝導度や示唆熱の測定により、K原子の濃度が濃くなるにつれて相転移温度が低下することが明らかとなったが、その変化はK原子の濃度に対して線形ではないことがわかった。中性子構造解析の結果、K原子は2つのMサイトのうちの一つを優先的に占有することがわかった。また、K原子の濃度が増えるにつれてSeO$$_{4}$$四面体のひずみが大きくなっていることがわかり、この歪が相転移温度の決定に大きな役割を果たしていることが示唆された。

口頭

J-PARCの大強度中性子を用いた結晶化学の新展開

大原 高志

no journal, , 

近年、茨城県東海村に建設されたJ-PARCの物質・生命科学実験施設(MLF)は陽子加速器による核破砕反応を利用した大強度パルス中性子実験施設であり、2008年からiBIX、2012年からSENJUという2台の単結晶回折計がそれぞれ稼働を開始した。これらの回折計ではパルス中性子の特徴を利用したtime-of-flight (TOF) Laue法によって広い逆空間を一度にスキャンできるため、J-PARCの大強度中性子と相まって従来に比べて小さい0.5mm角程度の単結晶試料を用いた測定が現実的なビームタイムで可能となった。加えて、SENJUでは極低温($$sim$$4K)や磁場($$sim$$7T)環境下での測定が可能であり、高温や高圧、電場といった様々な試料環境の整備も進めている。これにより、これまで結晶サイズの問題から測定を諦めざるを得なかった様々な機能性有機・有機金属結晶の単結晶中性子構造解析を、その機能が発現する環境下で実現できると期待される。

口頭

励起状態プロトン移動を示す有機発光材料2-(2'-hydroxyphenyl)benzimidazoleの単結晶中性子構造解析

大原 高志; 鬼柳 亮嗣; 花島 隆泰*; 茂吉 武人*; 中尾 朗子*; 宗像 孝司*; 黒田 哲也*

no journal, , 

分子内にN-H...O水素結合を持つ発色分子2-(2'-hydroxyphenyl)benzimidazol (HPBI)は可視光の照射によって励起状態プロトン移動(ESIPT)を伴う構造変化を起こすとともに、結晶状態では温度変化によってもプロトン移動由来と考えられる発光特性の変化を示すため、新規蛍光プローブやレーザー素子といった有機光機能性材料として注目されている。本研究では結晶状態特有の性質である温度変化によるプロトン移動を構造学的に確認するため、4Kおよび室温におけるHPBIの単結晶中性子構造解析をSENJUを用いて行った。構造精密化の結果、水素原子を含む全ての原子の座標および異方性温度因子を束縛条件なしで精密化することができた。N-H...O水素結合に注目したところ、室温では4Kに比べてわずかではあるがN-Hの伸長とH...Oの収縮が観測された。

口頭

Development of a cryostat for photo-crystallography on a TOF single crystal diffractometer SENJU

大原 高志; 花島 隆泰*; 宗像 孝司*; 茂吉 武人*; 鬼柳 亮嗣; 中尾 朗子*; 黒田 哲也*

no journal, , 

Photo-induced crystalline-state properties such as light-emission and magnetism of organic molecular crystals have been actively investigated because they can derive new photo-functional organic materials. In this research, we developed a new closed-cycle cryostat with 2-axes goniometer in which visible white light can be induced to carry out an in-situ single crystal neutron structure analysis of a photo-induced species in a single crystal on SENJU, a TOF-Laue single crystal diffractometer at MLF/J-PARC.

口頭

Single crystal neutron diffraction study of a crystalline-state photoisomerization by using a new TOF-Laue neutron diffractometer SENJU at J-PARC

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

no journal, , 

Single crystal neutron structure analysis is a powerful tool to study crystalline-state reactions because of its ability to distinguish deuterium atoms from hydrogen atoms. When the hydrogen atoms in specific positions of the reactive group are exchanged with deuterium atoms and the crystalline-state reaction proceeds, the hydrogen/deuterium migration in the reaction is easily observed by the neutron diffraction analysis and consequently the reaction mechanism is estimated. In this study, we performed a single crystal neutron diffraction measurement of a 3-cyanopropyl cobaloxime complex by using the same crystal of the previous study and a new TOF-Laue type single crystal neutron diffractometer SENJU at J-PARC. The result of the structure refinement showed that the chiral H-C*-D methylene group in the photo-produced 1-cyanopropyl group has the racemic form and an energy calculation suggested that one configuration was more preferable than the other. This indicates that the olefin formation and the racemization of the H-C*-D methylene group occurred after the 1-cyanopropyl group was formed by continuous photo-irradiation as predicted in the previous research.

口頭

Neutron structure analysis at J-PARC

大原 高志

no journal, , 

Single-crystal neutron diffraction is one of the most fundamental and powerful techniques to determine the arrangement of light elements and magnetic moments in crystalline materials with high accuracy and reliability. Recently, two single crystal neutron diffractometers, iBIX and SENJU, were built at J-PARC/MLF. Although those two diffractometers use similar detectors and software, character is quite different. iBIX equips a gas-stream type cryostat as a sample environment device and suitable for protein crystals and unstable molecular crystals. On the other hand, SENJU has a vacuum sample chamber for low-background measurements of small single crystal and various types of sample environment devices.

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