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論文

Ordered graphane nanoribbons synthesized via high-pressure diels-alder polymerization of 2,2'-bipyrazine

Li, F.*; Tang, X.*; Fei, Y.*; Zhang, J.*; Liu, J.*; Lang, P.*; Che, G.*; Zhao, Z.*; Zheng, Y.*; Fang, Y.*; et al.

Journal of the American Chemical Society, 147(17), p.14054 - 14059, 2025/04

https://doi.org/10.1021/jacs.5c03116
 被引用回数：0 パーセンタイル：0.00(Chemistry, Multidisciplinary)

2,2'-ビピラジン(BPZ)の圧力誘起重合により結晶性グラファンナノリボン(GANR)を合成した。中性子回折データのリートベルト精密化,核磁気共鳴スペクトル,赤外スペクトル,理論計算を行った結果、BPZは$$pi$$ $$cdots$$ $$pi$$積層した芳香環の間でディールス・アルダー重合し、並外れた長距離秩序を持つ伸びたボート型GANR構造を形成することがわかった。未反応の-C=N-基がボートの両端を橋渡ししており、さらなる機能化の余地がある。このGANRのバンドギャップは2.25eVであり、光電応答は良好である(I$$_{on}$$/I$$_{off}$$ =18.8)。われわれの研究は、高圧トポケミカル重合法が、特定の構造と望んだ特性を持つグラファンの精密な合成に有望な方法であることを強調している。

論文

Concurrent ${it operando}$ neutron imaging and diffraction analysis revealing spatial lithiation phase evolution in an ultra-thick graphite electrode

Strobl, M.*; Baur, M. E.*; Samothrakitis, S.*; Molamud, F.*; Zhang, X.*; Tung, P. K. M.*; Schmidt, S.*; Woracek, R.*; Lee, J.*; 鬼柳 亮嗣; et al.

Advanced Energy Materials, p.2405238_1 - 2405238_9, 2025/01

https://doi.org/10.1002/aenm.202405238

Energy-efficient, safe, and reliable Li-ion batteries (LIBs) are required for a wide range of applications. The introduction of ultra-thick graphite anodes, desired for high energy densities, meets limitations in internal electrode transport properties, leading to detrimental consequences. Yet, there is a lack of experimental tools capable of providing a complete view of local processes. Here, a multi-modal ${it operando}$ measurement approach is introduced, enabling quantitative spatio-temporal observations of Li concentrations and intercalation phases in ultra-thick graphite electrodes. Neutron imaging and diffraction concurrently provide correlated multiscale information from the scale of the cell down to the crystallographic scale. In particular, the evolving formation of the solid electrolyte interphase (SEI), observation of gradients in total lithium content, as well as in the formation of ordered Li$$_{x}$$C$$_{6}$$ phases and trapped lithium are mapped throughout the first charge-discharge cycle of the cell. Different lithiation stages co-exist during charging and discharging; delayed lithiation and delithiation processes are observed in central regions of the electrode, while the SEI formation, potential plating, and dead lithium are predominantly found closer to the interface with the separator. The study emphasizes the potential to investigate Li-ion diffusion and the kinetics of lithiation phase formation in thick electrodes.

論文

Multiple metamagnetic transitions in the helical antiferromagnet CeVGe$$_{3}$$

Jin, H.*; Choi, E. S.*; Wu, H.-C.*; Curro, N. J.*; 那波 和宏*; 佐藤 卓*; 鬼柳 亮嗣; 大原 高志; Klavins, P.*; Taufour, V.*

Physical Review B, 111(3), p.035103_1 - 035103_7, 2025/01

https://doi.org/10.1103/PhysRevB.111.035103
 被引用回数：0 パーセンタイル：0.00(Materials Science, Multidisciplinary)

We report on neutron diffraction, magnetoresistance, magnetization and magnetic torque measurements under high magnetic field in the helical antiferromagnet CeVGe$$_{3}$$. This compound exhibits Kondo lattice coherence and helical antiferromagnetic (AFM) ordering at ambient pressure, similar to the well-studied CeRhIn$$_{5}$$. Our measurements reveal that CeVGe$$_{3}$$ undergoes a magnetic transition from an incommensurate (ICM) AFM state to an up-up-down-down commensurate (CM) AFM structure, followed by a transition to a novel phase at higher fields. A quantum phase transition occurs around 21.3 T. This rich magnetic field phase diagram closely resembles that of CeRhIn$$_{5}$$. Furthermore, angle-dependent magnetoresistance measurements reveal that all transitions in CeVGe$$_{3}$$ occur from the field component along the ab plane. These findings highlight the intricate interplay among exchange interactions, crystal field effects, ground state properties, and crystalline symmetries.

論文

J-PARC/PLANETを用いた高圧下における高精度粉末中性子回折実験と最近の成果; 氷の高圧下における水素結合対称化の観測

服部 高典; 小松 一生*

日本原子力学会誌ATOMO$$Sigma$$, 66(12), p.618 - 622, 2024/12

https://doi.org/10.3327/jaesjb.66.12_618

超高圧中性子回折装置PLANETは、茨城県東海村の大強度陽子加速器施設J-PARCの物質・生命科学実験施設(MLF)に建設された国内初の高圧中性子実験専用のビームラインである。パルス中性子を用いたエネルギー分散型データ測定および最新の光学機器、高圧発生装置を導入することにより、これまでにない高い精度で、広い圧力温度範囲にわたる結晶・液体・ガラスの構造を解析できるようになっている。本稿では、どのようにしてそれが実現されたか紹介するとともに、最近発表された氷の水素結合の対称化の成果に関して紹介する。

論文

Nonferroelectric phase with loss of cycloidal magnetic structure in Tb$$_{0.515}$$Gd$$_{0.485}$$Mn$$_{2}$$O$$_{5}$$

石井 裕太*; 坂倉 輝俊*; 石川 喜久*; 鬼柳 亮嗣; Lustikova, J.*; 青山 拓也*; 大串 研也*; 若林 裕助*; 木村 宏之*; 野田 幸男*

Physical Review B, 110(18), p.184404_1 - 184404_7, 2024/11

https://doi.org/10.1103/PhysRevB.110.184404
 被引用回数：0 パーセンタイル：0.00(Materials Science, Multidisciplinary)

Neutron-scattering measurements were employed to investigate the magnetic ordering in Tb$$_{1-x}$$Gd$$_{x}$$Mn$$_{2}$$O$$_{5}$$ (x = 0.485) enriched with the $$^{160}$$Gd isotope, a member of multiferroic RMn$$_{2}$$O$$_{5}$$ (R = rare-earth element) compounds. This material, at low temperatures, exhibits commensurate magnetic (CM) ordering, which drives electric polarization. Notably, electric polarization diminishes as the temperature decreases further, while the CM ordering persists. Magnetic structure analyses revealed that a cycloidal magnetic structure along the c axis transforms into a sinusoidal-like structure, resulting in the nonferroelectric phase, whereas a collinear magnetic structure in the ab plane exhibits no significant change. The findings suggest that the cycloidal magnetic structure plays a key role in inducing electric polarization in the CM ordering of the present material.

論文

Gradient residual stress and fatigue life prediction of induction hardened carbon steel S38C axles; Experiment and simulation

Qin, T. Y.*; Hu, F. F.*; 徐 平光; Zhang, H.*; Zhou, L.*; Ao, N.*; Su, Y. H.; 菖蒲 敬久; Wu, S. C.*

International Journal of Fatigue, 185, p.108336_1 - 108336_13, 2024/08

https://doi.org/10.1016/j.ijfatigue.2024.108336
 被引用回数：8 パーセンタイル：94.71(Engineering, Mechanical)

Gradient distribution of triaxial residual stresses to a depth of several millimeters is retained in middle carbon steel S38C axles after high-frequency induction hardening, which has become a critical concern for fatigue structural integrity. To address this, the axial, hoop, and radial gradient residual strains inside the axles were measured for the first time by advanced neutron diffraction. The SIGINI Fortran subroutine was then adopted to reconstruct the global initial residual stress field from the measured data. Experimental and simulation results show that residual stresses of about -520 MPa (axial), -710 MPa (hoop), and -40 MPa (radial) residual stress were retained below the axle surface. Subsequently, the fatigue crack propagation behavior of S38C axles was numerically investigated in the framework of fracture mechanics. The calculated results clearly show that the compressive residual stresses at a depth of 0?3 mm from the axle surface lead to a low crack growth driving force, and that fatigue cracks do not propagate as long as the crack depth is less than 3.7 mm for hollow S38C axles. These results further indicate that the maximum defect size allowed in routine inspections is acceptable from a safety and economic point of view. Accurate measurement and characterization of the global gradient residual stress field through experiments and simulations can provide an important reference for optimizing the mileage intervals of nondestructive testing (NDT) of surface defects in these surface-strengthened railway axles.

論文

Hydroxyl group/fluorine disorder in deuterated magnesium hydroxyfluoride and behaviors of hydrogen bonds under high pressure

He, X.*; 鍵 裕之*; 小松 一生*; 飯塚 理子*; 岡島 元*; 服部 高典; 佐野 亜沙美; 町田 真一*; 阿部 淳*; 後藤 弘匡*; et al.

Journal of Molecular Structure, 1310, p.138271_1 - 138271_8, 2024/08

https://doi.org/10.1016/j.molstruc.2024.138271
 被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)

重水素化ヒドロキシフルオロマグネシウム[理想組成はMg(OD)F]のO-D$$cdotcdotcdot$$F水素結合の高圧応答を中性子粉末回折とラマン分光法を用いて調べた。常温でのリートベルト解析の結果、化学組成はMg(OD)$$_{0.920(12)}$$F$$_{1.080(12)}$$であり、結晶構造中で水酸基/フッ素(OD/F)が無秩序化して、2つの水素結合配置が生じていることが分かった。構造解析の結果、水素結合配置は9.8GPaまで維持され、圧力による水素結合の強化は見られなかった。常圧でのラマンスペクトルでは、2613, 2694, 2718cm$$^{-1}$$に3つの水酸基伸縮バンドが観測された。O-D伸縮モードの周波数が高いことから、ヒドロキシル基は弱い水素結合相互作用、あるいは水素結合を持たないことが示唆された。20.2GPaまでは、2694cm$$^{-1}$$を中心とするモードは圧力によってブルーシフトを示し、水素結合は圧縮されても強化されないことが明らかになった。これは、中性子回折の結果と一致した。水素結合の存否と、常圧および高圧での水酸基のブルーシフトの原因について議論した。

論文

Influence of interstitial carbon on bulk texture evolution of carbide-free high-entropy alloys during cold rolling using neutron diffraction

Fang, W.*; Liu, C.*; Zhang, J.*; 徐 平光; Peng, T.*; Liu, B.*; 諸岡 聡; Yin, F.*

Scripta Materialia, 249, p.116046_1 - 116046_6, 2024/08

https://doi.org/10.1016/j.scriptamat.2024.116046
 被引用回数：2 パーセンタイル：63.37(Nanoscience & Nanotechnology)

The influence of interstitial carbon on the texture evolution of high-entropy alloys during cold rolling was investigated. To prevent carbide formation, elements with weak carbon affinity were carefully selected in the (FeMnCoNi)$$_{96.5}$$C$$_{3.5}$$ alloy. Neutron diffraction, electron channeling contrast imaging, and electron backscatter diffraction were used to analyze the texture and microstructure evolution in alloys with and without carbon addition. Though their texture components are similar at the early stage of deformation, the Brass and Goss textures in the carbon-containing alloy at 50% cold rolling reduction are obviously higher than those in the carbon-free alloy, while Copper and S textures are lower. A large number of deformation twins induced in the carbon containing alloy is attributed as the significant reason for the texture differences. This work helps to understand the impact of interstitial carbon on the texture evolution of high-entropy alloys, providing valuable insights for microstructure and performance optimization.

論文

Gradient residual strain measurement procedure in surface impacted railway steel axles by using neutron scattering

Zhou, L.*; Zhang, H.*; Qin, T. Y.*; Hu, F. F.*; 徐 平光; Ao, N.*; Su, Y. H.; He, L. H.*; Li, X. H.*; Zhang, J. R.*; et al.

Metallurgical and Materials Transactions A, 55(7), p.2175 - 2185, 2024/07

https://doi.org/10.1007/s11661-024-07352-5
 被引用回数：3 パーセンタイル：75.40(Materials Science, Multidisciplinary)

High-speed railway S38C axles undergo surface induction hardening for durability, but are susceptible to fatigue cracks from foreign object impact. The neutron diffraction method was employed to measure the residual strain in S38C axles, obtaining microscopic lattice distortion data, for the gradient layer at a depth of 8 mm under the surface. The results showed that after induction-hardening, the microscopic lattice distortion had a gradient distribution, decreasing with the distance from the surface. However, in the case of impacting speed of 600 km/m, the average microscopic lattice distortion increased with the distance from the surface, reaching a maximum augmentation of 55 pct. These findings indicate a strong experimental basis, and improve our understanding of the relationship between macroscopic residual stress and decision-making, in regard to operation and maintenance.

論文

Hydrogen bond symmetrisation in D$$_2$$O ice observed by neutron diffraction

小松 一生*; 服部 高典; Klotz, S.*; 町田 真一*; 山下 恵史朗*; 伊藤 颯*; 小林 大輝*; 入舩 徹男*; 新名 亨*; 佐野 亜沙美; et al.

Nature Communications (Internet), 15, p.5100_1 - 5100_7, 2024/06

https://doi.org/10.1038/s41467-024-48932-8
 被引用回数：4 パーセンタイル：72.77(Multidisciplinary Sciences)

水素結合の対称化とは、水素原子が水素結合の中心に位置する現象である。理論的研究により、氷VIIの水素結合は、圧力が増加するにつれて、水素の分布を変化させながら、いくつかの中間状態を経て、最終的に対称化すると予測されている。これまで、多くの実験的研究が行われてきたにもかかわらず、その水素の位置や転移圧力は一貫していない。われわれは、100GPa以上の圧力で中性子回折実験を行い、氷中の水素分布を決定し、隣接酸素間での分布が80GPa付近で2つから1つになり水素結合が対称化することを世界で初めて観測した。

論文

Neutron diffraction; A Primer

Dronskowski, R.*; Br$"u$ckel, T.*; Kohlmann, H.*; Avdeev, M.*; Houben, A.*; Meven, M.*; Hofmann, M.*; 神山 崇*; Zobel, M.*; Schweika, W.*; et al.

Zeitschrift f$"u$r Kristallographie; Crystalline Materials, 239(5-6), p.139 - 166, 2024/06

https://doi.org/10.1515/zkri-2024-0001
 被引用回数：4 パーセンタイル：92.46(Crystallography)

中性子回折は結晶線や関連物質の構造を決定するための最も強力な技術のひとつと考えられる。中性子は核分裂、核破砕、低エネルギー核反応から放出され、粉末回折法、飛行時間法、単結晶法、その他、結晶や磁性体の構造を明らかにするのに最適な技術として利用することができる。高い中性子束と十分な輝度を利用した中性子回折では、散漫散乱にも活用でき、オペランド実験や、新物質の高圧実験にも適している。また中性子の同位体を区別、磁性を決定できるという利点は、例えばエネルギー変換・貯蔵材料、磁性体、タンパク質構造における軽元素の構造とダイナミクスに関する重要な科学的疑問に答える上でも極めて重要である。この論文では、中性子回折の現状を要約するとともに、最近の進歩や新しいアイデア、例えば新しい装置の設計、そしてそこから派生するものについてもレビューする。

論文

Hydrogenation of silicon-bearing hexagonal close-packed iron and its implications for density deficits in the inner core

森 悠一郎*; 鍵 裕之*; 青木 勝敏*; 高野 将大*; 柿澤 翔*; 佐野 亜沙美; 舟越 賢一*

Earth and Planetary Science Letters, 634, p.118673_1 - 118673_8, 2024/05

https://doi.org/10.1016/j.epsl.2024.118673
 被引用回数：1 パーセンタイル：47.42(Geochemistry & Geophysics)

水素による鉄の体積膨張に対するケイ素の効果を調べるため、高圧高温下でのhcp-Fe$$_{0.95}$$Si$$_{0.05}$$の中性子回折実験とX線回折実験を行った。中性子回折実験は重水素化hcp-Fe$$_{0.95}$$Si$$_{0.05}$$に対して13.5GPa, 900K及び12.1GPa, 300Kで行い、得られたプロファイルからリートベルト解析を用いて水素占有率を決定した。hcp-Fe-SiのP-V-T状態方程式を組み合わせることにより、hcp-Fe$$_{0.95}$$Si$$_{0.05}$$の水素による体積膨張が純粋なhcp鉄の体積膨張よりも10%大きいことを示した。得られた値を用いて、内核の密度欠損を再現できる水素量を見積もったところ、シリコンの影響がない場合に比べて50%減少した。hcp-Fe$$_{0.95}$$Si$$_{0.05}$$で内核の密度欠損を再現した場合、内核と外核で可能な水素量xはそれぞれ0.07と0.12-0.15と計算された。

論文

Recrystallization of bulk nanostructured magnesium alloy AZ31 after severe plastic deformation; An in situ diffraction study

Liss, K.-D.*; Han, J.-K.*; Blankenburg, M.*; Lienert, U.*; Harjo, S.; 川崎 卓郎; 徐 平光; 行武 栄太郎*; Kawasaki, M.*

Journal of Materials Science, 59(14), p.5831 - 5853, 2024/04

https://doi.org/10.1007/s10853-023-09250-4
 被引用回数：4 パーセンタイル：69.57(Materials Science, Multidisciplinary)

The magnesium alloy AZ31, which has undergone high-pressure torsion processing, was subjected to in situ annealing micro-beam synchrotron high-energy X-ray diffraction and compared to the as-received rolled sheet material that was investigated through in situ neutron diffraction. While the latter only exhibits thermal expansion and minor recovery, the nanostructured specimen displays a complex evolution, including recovery, strong recrystallization, phase transformations, and various regimes of grain growth. Nanometer-scale grain sizes, determined using Williamson-Hall analysis, exhibit seamless growth, aligning with the transition to larger grains, as assessed through the occupancy of single grain reflections on the diffraction rings. The study uncovers strain anomalies resulting from thermal expansion, segregation of Al atoms, and the kinetics of vacancy creation and annihilation. Notably, a substantial number of excess vacancies were generated through high-pressure torsion, and maintained for driving the recrystallization and forming highly activated volumes for diffusion and phase precipitation during heating. The unsystematic scatter observed in the Williamson-Hall plot indicates high dislocation densities following severe plastic deformation, which significantly decreases during recrystallization. Subsequently, dislocations reappear during grain growth, likely in response to torque gradients in larger grains. It is worth noting that the characteristics of unsystematic scatter differ for dislocations created at high and low temperatures, underscoring the strong temperature dependence of slip system activation.

論文

Development of 0.5 mm gauge size radial collimators for high-pressure neutron diffraction experiments at PLANET in J-PARC

服部 高典; 鈴木 浩二*; 三代 達也*; 伊藤 崇芳*; 町田 真一*

Nuclear Instruments and Methods in Physics Research A, 1059, p.168956_1 - 168956_9, 2024/02

https://doi.org/10.1016/j.nima.2023.168956
 被引用回数：2 パーセンタイル：46.61(Instruments & Instrumentation)

見込み幅0.5mmのラジアルコリメータを高圧中性子回折実験用に特別に設計し、その性能と有効性を調べた。0.75mm, 1.5mm, 3.0mmのラジアルコリメータはそれぞれ0.50mm, 1.07mm, 2.78mmのみこみ幅を示した。3つのラジアルコリメータの透過率はすべて同等であった。Paris-Edinburgh(PE)プレスとdiamond anvil cell (DAC)を使用した評価では、見込み幅0.5mmラジアルコリメータを使用した場合、アンビル散乱はかなり減少し、サンプル/アンビル信号比はPEプレスとDACでそれぞれ0.5と2.0に達した。これらの結果は、見込み幅0.5mmラジアルコリメータが意図したとおりに製作され、高圧中性子回折実験(特に30GPaを超える実験)に有効であることを示している。今回作成されたラジアルコリメータの見込み幅は、これまで世界の中性子散乱実験用に製作されたものの中で、最も小さい見込み幅を持つものである。

論文

Principal preferred orientation evaluation of steel materials using time-of-flight neutron diffraction

徐 平光; Zhang, S.-Y.*; Harjo, S.; Vogel, S. C.*; 友田 陽*

Quantum Beam Science (Internet), 8(1), p.7_1 - 7_13, 2024/01

https://doi.org/10.3390/qubs8010007

Comprehensive information about the ${it in situ}$ microstructure and crystal structure evolution during the preparation/production processes of various materials is in great demand in order to precisely control the microstructure morphology and the preferred orientation characteristics for the excellent strength-ductility-toughness balance of advanced engineering materials. ${it In situ}$ isothermal annealing experiments of cold rolled 17Ni-0.2C (mass %) martensitic steel sheets were carried out by using the TAKUMI and ENGIN-X time-of-flight neutron diffractometers, respectively. The inverse pole figures based on full-profile refinement were extracted to roughly evaluate the preferred orientation features along three principal sample directions of investigated steel sheets using the General Structure Analysis System (GSAS) software with built-in generalized spherical harmonic functions. The consistent rolling direction (RD) inverse pole figures from TAKUMI and ENGIN-X have confirmed that the time-of-flight neutron diffraction has high repeatability and statistical reliability, revealing that the principal preferred orientation evaluation of steel materials is available through 90$$^{circ}$$ TD $$rightarrow$$ ND (transverse direction $$rightarrow$$ normal direction) rotation of the investigated specimen on the sample stage during two neutron diffraction experiments. Moreover, these RD, TD and ND inverse pole figures before and after in situ experiments were compared with the corresponding inverse pole figures recalculated respectively from the MUSASI-L complete pole figure measurement and the HIPPO in situ microstructure evaluation. The similar orientation distribution characteristics suggested that the principal preferred orientation evaluation method can be applied to in situ microstructure evolution of bulk orthorhombic materials and spatially resolved principal preferred orientation mappings of large engineering structure parts.

論文

The Hydrogen-bond network in sodium chloride tridecahydrate; Analogy with ice VI

山下 恵史朗*; 中山 和也*; 小松 一生*; 大原 高志; 宗像 孝司*; 服部 高典; 佐野 亜沙美; 鍵 裕之*

Acta Crystallographica Section B; Structural Science, Crystal Engineering and Materials (Internet), 79(5), p.414 - 426, 2023/10

https://doi.org/10.1107/S2052520623007199
 被引用回数：2 パーセンタイル：43.78(Chemistry, Multidisciplinary)

最近発見された塩化ナトリウムの超水和物(NaCl$$cdot$$ 13H(D)$$_{2}$$O)の構造を1.7GPa, 298Kでのその場単結晶中性子回折によって決定した。この物質は大きな水素結合ネットワークを持ち、いくつかの水分子は分岐水素結合や5配位水分子のような歪んだ結合の特徴を持つ。水素結合ネットワークは、ネットワークトポロジーと水素結合の無秩序性という点で、氷VIと類似している。擬似対称性によって接続されたネットワークの構成要素を区別しなければ、このハイドレートの全体的なネットワーク構造は、氷VIのネットワーク構造に対応する小さな構造単位に分解することで表現できる。この水素結合ネットワークは、既知の塩水和物とは対照的に、水分子の配向の乱れを含んでいる。ここでは、イオン種を含む水素結合ネットワークに関するさらなる洞察のための例を示す。

論文

Deuterium content and site occupancy in iron sulfide at high pressure and temperature determined using in situ neutron diffraction measurements

Abeykoon, S.*; Howard, C.*; Dominijanni, S.*; Eberhard, L.*; Kurnosov, A.*; Frost, D. J.*; Boffa Ballaran, T.*; 寺崎 英紀*; 坂巻 竜也*; 鈴木 昭夫*; et al.

Journal of Geophysical Research; Solid Earth, 128(9), p.e2023JB026710_1 - e2023JB026710_17, 2023/09

https://doi.org/10.1029/2023JB026710
 被引用回数：2 パーセンタイル：32.37(Geochemistry & Geophysics)

少量の硫化鉄鉱物は、地球のマントルから産出するほとんどの岩石や、天然のダイヤモンドに内包物として含まれている。水素は高温高圧下で硫化鉄鉱物に溶解している可能性があるが、地表の温度と圧力では失われている。本研究では、高温高圧下における硫化鉄中の重水素量を、11.4GPa, 1300Kまでの条件でJ-PARCのPLANETでの6軸型マルチアンビルプレスを用いたその場観察中性子回折実験により決定した。硫化鉄水素化物中の全重水素含有量は高温高圧下で増加することが明らかになった。この結果を用いて、大陸深部のリソスフェアマントル中の硫化鉄鉱物の水素含有量を見積もったところ、1700-2700ppmの範囲にあることがわかった。これはバルクマントル中の約2-3ppmの水素に相当する。

論文

Strengthening of $$alpha$$Mg and long-period stacking ordered phases in a Mg-Zn-Y alloy by hot-extrusion with low extrusion ratio

Harjo, S.; Gong, W.; 相澤 一也; 川崎 卓郎; 山崎 倫昭*

Acta Materialia, 255, p.119029_1 - 119029_12, 2023/08

https://doi.org/10.1016/j.actamat.2023.119029
 被引用回数：28 パーセンタイル：96.68(Materials Science, Multidisciplinary)

An as-cast sample and two hot-extruded samples with different extrusion ratios (R) of Mg$$_{97}$$Zn$$_{1}$$Y$$_{2}$$ alloy containing the HCP $$alpha$$ matrix ($$alpha$$Mg) and the long-period stacking ordered phase (LPSO) of about 25-vol%, were used in tensile deformation in situ neutron diffraction experiments, to elucidate the effects of uniquely different microstructural evolutions in $$alpha$$Mg and LPSO with varying the R value to the mechanical properties. $$alpha$$Mg behaved as the soft phase and LPSO as the hard phase, and hot-extrusion improved the strength of both. At the R value of 5.0, a bimodal microstructure was created in $$alpha$$Mg, increasing largely the yield strength of $$alpha$$Mg. With increasing the R value to 12.5, the bimodal microstructure of $$alpha$$Mg collapsed and the yield strength of $$alpha$$Mg decreased. However, the strength of LPSO increased monotonously with increasing the R value due to the developments of kink bands and texture.

論文

Development of an iron(II) complex exhibiting thermal- and photoinduced double proton-transfer-coupled spin transition in a short hydrogen bond

中西 匠*; 堀 優太*; 重田 育照*; 佐藤 寛泰*; 鬼柳 亮嗣; 宗像 孝司*; 大原 高志; 岡澤 厚*; 島田 林太郎*; 坂本 章*; et al.

Journal of the American Chemical Society, 145(35), p.19177 - 19181, 2023/08

https://doi.org/10.1021/jacs.3c06323
 被引用回数：5 パーセンタイル：51.73(Chemistry, Multidisciplinary)

Multiple proton transfer (PT) controllable by external stimuli plays a crucial role in fundamental chemistry, biological activity, and material science. However, in crystalline systems, controlling multiple PT, which results in a distinct protonation state, remains challenging. In this study, we developed a novel tridentate ligand and iron(II) complex with a short hydrogen bond (HB) that exhibits a PT-coupled spin transition (PCST). Single-crystal X-ray and neutron diffraction measurements revealed that the positions of the two protons in the complex can be controlled by temperature and photoirradiation based on the thermal- and photoinduced PCST. The obtained results suggest that designing molecules that form short HBs is a promising approach for developing multiple PT systems in crystals.

論文

Magnetic ordering and structural phase transitions of Nd$$_{3}$$$$T$$$$_{4}$$Sn$$_{13}$$ ($$T$$ = Rh and Ir)

下田 愛海*; 岩佐 和晃*; 桑原 慶太郎*; 佐賀山 基*; 中尾 裕則*; 石角 元志*; 大原 高志; 中尾 朗子*; 星川 晃範*; 石垣 徹*

JPS Conference Proceedings (Internet), 38, p.011091_1 - 011091_6, 2023/05

https://doi.org/10.7566/JPSCP.38.011091

Synchrotron X-ray diffraction study revealed that Nd$$_{3}$$$$T$$$$_{4}$$Sn$$_{13}$$ ($$T$$ = Rh and Ir) undergo structural phase transitions characterized by the wave vector $$q$$$$_{rm L}$$=(1/2,1/2,0). Neutron diffraction study revealed antiferromagnetic ordering below $$T$$$$_{rm N}$$ = 1.65 and 1.42 K for Nd$$_{3}$$Rh$$_{4}$$Sn$$_{13}$$ and Nd$$_{3}$$Ir$$_{4}$$Sn$$_{13}$$, respectively, which is similar to that previously reported for Nd$$_{3}$$Co$$_{4}$$Sn$$_{13}$$. These compounds show a magnetic susceptibility saturation behavior below approximately 3 K. The results indicate emergence of anomalous electronic correlation in Nd$$_{3}$$$$T$$$$_{4}$$Sn$$_{13}$$ ($$T$$ = Co, Rh, and Ir) above $$T$$$$_{rm N}$$.

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