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Mao, W.*; Gong, W.; 川崎 卓郎; Gao, S.*; 伊東 達矢; 山下 享介*; Harjo, S.; Zhao, L.*; Wang, Q.*
Scripta Materialia, 264, p.116726_1 - 116726_6, 2025/07
被引用回数：0 パーセンタイル：0.00(Nanoscience & Nanotechnology)An ultrafine-grained 304 austenitic stainless steel exhibited pronounced serrated Luders deformation at 20 K, with stress and temperature oscillations reaching 200 MPa and 20 K. 
neutron diffraction and digital image correlation revealed discontinuous Luders band propagation and burst martensite formation. During deformation, austenite phase stress remained lower than at upper yielding, indicating elastic behavior. Notably, martensite phase stress stayed lower than austenite until fracture, likely due to stress relaxation from burst martensitic transformation at 20 K. The low martensite stress delayed brittle fracture until austenite plastically yielded during uniform deformation.
Co
)Sn studied by 
SRCai, Y.*; Yoon, S.*; Sheng, Q.*; Zhao, G.*; Seewald, E. F.*; Ghosh, S.*; Ingham, J.*; Pasupathy, A. N.*; Queiroz, R.*; Lei, H.*; et al.
Physical Review B, 111(21), p.214412_1 - 214412_17, 2025/06
被引用回数：0We study the magnetic properties of the metallic kagome system (FeCo)Sn by a combination of muon spin relaxation (SR), magnetic susceptibility, and scanning tunneling microscopy (STM) measurements in single crystal specimens with Co concentrations 
= 0, 0.11, 0.8. In the undoped antiferromagnetic compound FeSn, we find possible signatures for a previously unidentified phase that sets in at 
~K, well beneath the Neel temperature 
~K as indicated by a peak in the relaxation rate 1/
observed in zero field (ZF) and longitudinal field (LF) SR measurements, with a corresponding anomaly in the ac and dc susceptibility, and an increase in the static width 1/
in ZF-SR measurements. No signatures of spatial symmetry breaking are found in STM down to 7~K. Related to the location and motion of muons in FeSn, we confirmed a previous report that about 40% of the implanted muons reside at a field-cancelling high symmetry site at 
~K, while an onset of thermal hopping changes the site occupancy at higher temperatures. In Fe
Co
Sn, where disorder eliminated the field-cancellation effect, all the implanted muons exhibit precession and/or relaxation in the ordered state. In Fe
Co
Sn, we find canonical spin glass behavior with freezing temperature 
~K; the ZF and LF-SR time spectra exhibit results similar to those observed in dilute alloy spin glasses CuMn and AuFe, with a critical behavior of 
at 
and 
as 
. The absence of spin dynamics at low temperatures makes a clear contrast to the spin dynamics observed by SR in many geometrically frustrated spin systems on insulating kagome, pyrochlore, and triangular lattices. The spin glass behavior of CoSn doped with dilute Fe moments is shown to originate primarily from the randomness of doped Fe moments rather than due to geometrical frustration of the underlying lattice.
Ling, B.-K.*; Chang, M.*; Zhai, Y.-Q.*; Deng, J.*; 古府 麻衣子*; Guo, H.*; Zhao, J.*; Fu, Z.*; Zheng, Y.-Z.*
Journal of the American Chemical Society, 147(13), p.10935 - 10942, 2025/03
被引用回数：1 パーセンタイル：83.04(Chemistry, Multidisciplinary)The efficient excitation and controlled propagation of nanoscale spin waves remain significant challenges, as their intrinsic dispersion relations are primarily determined by magnetic dipole and exchange interactions. Here we report the first observed coexistence of quantum spin wave excitation and single-molecule magnet behavior in a mixed chromium(III) and dysprosium(III) complex, namely Dy
Cr
(
-F)(mdea)
(piv)
, which shows a large ferrimagnetic ground moment with a restricted quantum tunneling gap (
3.8 
10
cm
) up to nine levels, leading to an axial anisotropic energy barrier of 12 cm and opened hysteresis loop at 0.4 K.
-
transitionsYang, Q.*; Yang, X.*; Wang, Y.*; Fei, Y.*; Li, F.*; Zheng, H.*; Li, K.*; Han, Y.*; 服部 高典; Zhu, P.*; et al.
Nature Communications (Internet), 15, p.7778_1 - 7778_9, 2024/09
被引用回数：11 パーセンタイル：88.19(Multidisciplinary Sciences)明るい一重項励起子と三重項励起子を同時に発現する発光材料は、オプトエレクトロニクス、サイネージ、情報暗号化において大きな可能性を秘めている。しかしながら、高性能の白色発光を実現するためには、蛍光と燐光の寄与が不均衡であることが大きな障害となっている。ここでは、水素結合の協同効果による圧力処理エンジニアリングによって、n--遷移の混合を実現し、イソフタル酸(IPA)中で三重項状態の発光を7%から40%に高めることで、この課題に対処した。加圧処理したIPAでは、蛍光と燐光のハイブリッドに基づく優れた白色発光が得られ、フォトルミネッセンス量子収率は当初の19%(青色発光)から75%に増加した。その場での高圧IRスペクトル、X線回折、中性子回折から、圧力の上昇に伴い水素結合が連続的に強化されることが明らかになった。さらに、この強化された水素結合は、圧力処理後も常圧条件下まで保持され、バランスの取れた一重項/三重項励起子集団のための効率的な系間交差を目的としたIPAに与え、効率的な白色発光をもたらした。この研究は、有機低分子の三重項状態を明るくするルートを提案するだけでなく、一重項励起子と三重項励起子の比率を調節して、高性能の白色発光を構築するものである。
Gu, Y. Q.*; Gu, Y. M.*; Liu, F.*; 河村 聖子; 村井 直樹; Zhao, J.*
Physical Review Letters, 132(24), p.246702_1 - 246702_7, 2024/06
被引用回数：2 パーセンタイル：64.46(Physics, Multidisciplinary)Materials manifesting the Kitaev model, characterized by bond-dependent interactions on a honeycomb lattice, can host exotic phenomena like quantum spin liquid states and topological magnetic excitations. However, finding such materials remains a formidable challenge. Here, we report high-resolution inelastic neutron scattering measurements performed on VI, a van der Waals ferromagnetic Mott insulator, covering a wide range of reciprocal space. Our measurements unveil highly anisotropic magnetic excitations in momentum space. Through a comprehensive comparative analysis of various models that incorporate diverse symmetry-allowed magnetic interactions, we find the observed excitations are well captured by a model with a large bond-dependent Kitaev interaction. These results not only help to understand the intriguing properties of VI, such as the pronounced anomalous thermal Hall effects and strong pressure or structure dependence of magnetism, but also open a new avenue for exploring Kitaev physics.
小林 重人*; 樽田 泰宜; Zhao, Q.*; 橋本 敬*
横幹, 18(1), p.26 - 36, 2024/04
The decommissioning of nuclear power plants and staff turnover may lead to a depletion of accumulated knowledge. Despite the implementation of nuclear knowledge management, current efforts primarily focus on preserving knowledge without adequate consideration of knowledge creation and inheritance. This study examines the correlation between generativity, job competence, and social support among nuclear power plant staff in the decommissioning process. Generativity refers to the capacity to create something new, promote it, and pass it on to future generations. The research hypothesis posits that staff with plant operating experience will exhibit lower generativity scores than those without such experience. However, the results indicate no substantial variation in generativity scores, but there is a significantly higher social support score among staff with operating experience. The study highlights the significance of knowledge management, incorporating the concept of generativity, in facilitating knowledge acquisition activities across the organization.
Hu, Q.*; Wang, Q. M.*; Zhang, T.*; Zhao, C.*; Iltaf, K. H.*; Liu, S. Q.*; 深津 勇太
Energy Reports (Internet), 9, p.3661 - 3682, 2023/12
被引用回数：11 パーセンタイル：64.37(Energy & Fuels)This study evaluates petrophysical properties of representative geological rocks in the context of injectivity, storage space, and caprock integrity for effective utilization and long-term storage of carbon dioxide. A total of 10 geological rocks were selected as representative storage media for consideration as saline aquifers & depleted oil and gas reservoirs, basalts, and cap rocks, as well as utilization in organic-rich shale and coal seams. An integrated suite of laboratory tests, including liquid immersion porosimetry, gas expansion porosimetry, grain size distribution, mercury intrusion porosimetry, and gas diffusion, were performed on these various rock samples. The results exhibit a disparity of petrophysical properties among two broad groups of rocks: rocks selected for possible storage of CO have porosities of 
10-25%, permeabilities of 10
-10
m
, m-sized pore-throat size distribution, and mostly good pore connectivity; in contrast, the potential caprocks have porosities of 0.5-5%, permeabilities of 10
-10
m, pore throat sizes of 50 nm, and probably poorly connected pore networks. An understanding of the measured facets of pore structure and contribution of fractures is also critical in the context of different testing principles and data interpretation of petrophysical analyses, as well as observational scales in the laboratory and field, and therefore reliable confidence of CO storage and utilization performance. Our work further illustrates the controlling influence of grain size distribution and geological processes on pore size distribution and pore connectivity for a wide range of rock types and lithologies, and particularly presents the extent and behavior of CO gas diffusion with a custom-designed apparatus for a holistic understanding of various petrophysical attributes of widely different geological rocks.
Shangguan, Y.*; Bao, S.*; Dong, Z.-Y.*; Xi, N.*; Gao, Y.-P.*; Ma, Z.*; Wang, W.*; Qi, Z.*; Zhang, S.*; Huang, Z.*; et al.
Nature Physics, 19(12), p.1883 - 1889, 2023/09
被引用回数：19 パーセンタイル：93.50(Physics, Multidisciplinary)The magnetization of a quantum magnet can be pinned at a fraction of its saturated value by collective effects. One example of such a plateau phase is found in spin-1/2 triangular-lattice antiferromagnets. They feature strong geometrical frustration and the plateau phase therein is often interpreted as arising from an order-by-disorder mechanism driven by quantum fluctuations. Here we observe a one-third magnetization plateau under an applied magnetic field in the spin-1 antiferromagnet NaNiBiO
with a honeycomb lattice, which, with conventional magnetic interactions, would not be geometrically frustrated. Based on our elastic neutron scattering measurements, we propose the spin structure of the plateau phase to be an unusual partial spin-flop ferrimagnetic order. Our theoretical calculations indicate that bond-anisotropic Kitaev interactions are the source of frustration that produces the plateau. These results suggest that Kitaev interactions provide a different route to frustration and phases driven by quantum fluctuations in high-spin magnets.
Yuan, X.*; Hu, Q.*; Lin, X.*; Zhao, C.*; Wang, Q.*; 舘 幸男; 深津 勇太; 濱本 昌一郎*; Siitari-Kauppi, M.*; Li, X.*
Journal of Hydrology, 618, p.129172_1 - 129172_15, 2023/03
被引用回数：6 パーセンタイル：58.63(Engineering, Civil)Mass transport in geomedia as influenced by the pore structure is an important phenomenon. Six rocks (granodiorite, limestone, two chalks, mudstone, and dolostone) with different extents of heterogeneity at six different particle sizes were studied to describe the effects of pore connectivity on mass transport. The multiple methods applied were porosity measurement, gas diffusion test, and batch sorption test of multiple ions. Porosity measurement results reveal that with decreasing particle sizes, the effective porosities for the "heterogenous" group (granodiorite and limestone) increase, whereas the porosities of "homogeneous" group (chalks, mudstone, and dolostone) roughly remain constant. Gas diffusion results show that the intraparticle gas diffusion coefficient among these two groups, varying in the magnitude of 10
to 10
m/s. The batch sorption work displays a different affinity of these rocks for tracers, which are related to their mineral components. For granodiorite, mudstone, and dolostone, the adsorption capacity increases as the particle size decreases, due to higher specific surface area in smaller particle-size. In general, this integrated research of grain size distribution, rock porosity, intraparticle diffusivity, and ionic sorption capacity gives insights into the pore connectivity effect on both gas diffusion and chemical transport behaviors for different lithologies and/or different particle sizes.
BaCo(PO)Sheng, J.*; Wang, L.*; Candini, A.*; Jiang, W.*; Huang, L.*; Xi, B.*; Zhao, J.*; Ge, H.*; Zhao, N.*; Fu, Y.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(51), p.e2211193119_1 - e2211193119_9, 2022/12
被引用回数：34 パーセンタイル：93.63(Multidisciplinary Sciences)Although considerable progress has been made in the theoretical understanding of the low-dimensional frustrated quantum magnets, experimental realizations of a well-established scaling analysis are still scarce. This is particularly true for the two-dimensional antiferromagnetic triangular lattices. Owing to the small exchange strength, the newly discovered compound NaBaCo(PO) provides a rare opportunity for clarifying the quantum criticality in an ideal triangular lattice with quantum spin S=1/2. In addition to the establishment of the complete phase diagrams, the spin Hamiltonian with a negligible interplane interaction has been determined through the spin wave dispersion in the polarized state, which is consistent with the observation of a two-dimensional quantum critical point with the Bose-Einstein condensation of diluted free bosons.
Wang, Q.*; Hu, Q.*; Zhao, C.*; Yang, X.*; Zhang, T.*; Ilavsky, J.*; Kuzmenko, I.*; Ma, B.*; 舘 幸男
International Journal of Coal Geology, 261, p.104093_1 - 104093_15, 2022/09
被引用回数：12 パーセンタイル：69.82(Energy & Fuels)To understanding the spatial heterogeneity of mineral and pore structure variations in fine-grained shale, microscale X-ray fluorescence (micro-XRF) mapping, (ultra-) small-angle X-ray scattering [(U)SAXS] and wide-angle X-ray scattering were applied for two samples from a piece of Eagle Ford Shale in South Texas. Thin section petrography and field emission-scanning electron microscopy, X-ray diffraction (XRD), total organic carbon, and pyrolysis were also utilized to investigate the potential spatial heterogeneity of pore types, mineral and organic matter compositions for both samples. Overall, the siliceous-carbonate mineral contents in these carbonate-rich Eagle Ford Shale vary between laminations at mm scales. By analyzing six selected sub-samples on each of two samples with X-ray scattering and XRD techniques, nm-sized pores are mainly interparticle ones in the higher calcite regions, where the porosity is also relatively lower, while the lower calcite regions consist of both interparticle and intraparticle pore types with higher porosity. Finally, the micro-XRF and (U)SAXS are combined to generate porosity distribution maps to provide more insights about its heterogeneity related to the laminations and fractures at our observational scales.
; SR studies and charge-spin percolation modelSheng, Q.*; 金子 竜也*; Yamakawa, Kohtaro*; Guguchia, Z.*; Gong, Z.*; Zhao, G.*; Dai, G.*; Jin, C.*; Guo, S.*; Fu, L.*; et al.
Physical Review Research (Internet), 4(3), p.033172_1 - 033172_14, 2022/09
A pyrite system NiS
Se exhibits a bandwidth controlled Mott transition via (S,Se) substitutions in a two-step process: the antiferromagnetic insulator (AFI) to antiferromagnetic metal (AFM) transition at 
0.45 followed by the AFM to paramagnetic metal (PMM) transition at 1.0. Among a few other Mott systems which exhibit similar two-step transitions, Ni(S,Se) is of particular interest because a large intermediate AFM region in the phase diagram would provide unique opportunities to study the interplay between the spin and charge order. By comparing and combining our muon spin relaxation studies and previous neutron scattering studies, here we propose a picture where the spin order is maintained by the percolation of "nonmetallic" localized and dangling Ni moments surrounded by S, while the charge transition from AFI to AFM is caused by the percolation of the conducting paths generated by the Ni-Se-Ni bonds.
and Eu
ions onto sedimentary rock in the presence of gamma-irradiated humic acidZhao, Q.*; 齊藤 毅*; 宮川 和也; 笹本 広; 小林 大志*; 佐々木 隆之*
Journal of Hazardous Materials, 428, p.128211_1 - 128211_10, 2022/04
被引用回数：7 パーセンタイル：45.72(Engineering, Environmental)令和2年度以降の幌延深地層研究計画において原子力機構が取り組んでいる課題の1つである「実際の地質環境における人工バリアの適用性確認」では、坑道周辺の掘削損傷領域において物質移行に関するデータの取得が必要である。本研究では、地下水中に含まれる腐植物質であるフミン酸に着目し、放射線によるフミン酸の分解反応がCsイオンとEuイオンの収着能へ与える影響について、幌延地域の堆積岩を例として調べた。放射線を照射していないフミン酸の存在下では、Euはフミン酸と錯体を形成することで、岩石への収着能は低下する。一方で、放射線の照射によりフミン酸が分解されると、岩石へ収着するEuイオンが増加することが確認された。また、Csの岩石への収着能はフミン酸の影響を受けることが無く、また、放射線により分解されたフミン酸の影響も見られないことが分かった。以上のことから、廃棄体の近傍ではフミン酸の放射線分解により、岩石への収着するEuイオンの割合が大きくなることが考えられる。
Hao, Y. Q.*; Wo, H. L.*; Gu, Y. M.*; Zhang, X. W.*; Gu, Y. Q.*; Zheng, S. Y.*; Zhao, Y.*; Xu, G. Y.*; Lynn, J. W.*; 中島 健次; et al.
Science China; Physics, Mechanics & Astronomy, 64(3), p.237411_1 - 237411_6, 2021/03
被引用回数：12 パーセンタイル：69.00(Physics, Multidisciplinary)We report thermodynamic and neutron diffraction measurements on the magnetic ordering properties of the honeycomb lattice magnet YbCl. We find YbCl exhibits a N
el type long-range magnetic order at the wavevector (0, 0, 0) below T
= 600 mK. This magnetic order is associated with a small sharp peak in heat capacity and most magnetic entropy release occurs above the magnetic ordering temperature. The magnetic moment lies in-plane, parallel to the monoclinic a-axis, whose magnitude m
= 0.86(3) 
is considerably smaller than the expected fully ordered moment of 2.24 for the doublet crystal-field ground state. The magnetic ordering moment gradually increases with increasing magnetic field perpendicular to the ab-plane, reaching a maximum value of 1.6(2) at 4 T, before it is completely suppressed above 9 T. These results indicate the presence of strong quantum fluctuations in YbCl.
Wang, Y.*; Jia, G.*; Cui, X.*; Zhao, X.*; Zhang, Q.*; Gu, L.*; Zheng, L.*; Li, L. H.*; Wu, Q.*; Singh, D. J.*; et al.
Chem, 7(2), p.436 - 449, 2021/02
被引用回数：297 パーセンタイル：99.75(Chemistry, Multidisciplinary)Nanozymes are promising alternatives to natural enzymes, but their use remains limited owing to poor specificity. Overcoming this is extremely challenging due to the intrinsic structural complexity of these systems. We report theoretical design and experimental realization of a series of heterogeneous molybdenum single-atom nanozymes (named Mo
-N
-C), wherein we find that the peroxidase-like specificity is well regulated by the coordination numbers of single Mo sites. The resulting Mo-N-C catalyst shows exclusive peroxidase-like behavior. It achieves this behavior via a homolytic pathway, whereas Mo-N-C and Mo-N-C catalysts have a different heterolytic pathway. The mechanism of this coordination-number-dependent enzymatic specificity is attributed to geometrical structure differences and orientation relationships of the frontier molecular orbitals.
Zhao, Q.*; 樽田 泰宜; 小林 重人*; 橋本 敬*
知識共創(インターネット), 9, p.III 1_1 - III 1_9, 2019/06
近年の技術発展の加速によって既存の知識の陳腐化が加速しており、そうした知識を他の人に継承できなくなることで、世代継承性が低下する怖れがある。本研究の目的は、知識継承ができなくなることによる世代継承性への影響と知識継承行動との関係を明らかにし、さらにそれらと相関する要因を明らかにすることである。そのための方法として廃止措置中にある原子力発電所の職員を対象に、調査票調査を実施した。主な結果として、(1)運転経験の有無によって世代継承性,有能感,知識継承行動の得点に有意差がないこと、(2)運転経験の有無に関わらず有能感,知識継承行動と世代継承性の得点の間に正の相関があったことの2点が明らかとなった。以上の結果から運転経験がある職員は能動的に新しい知識を獲得することによって仕事の有能感と知識継承行動を向上させ、それらが世代継承性を下支えしていることが示唆された。
GeWo, H.*; Wang, Q.*; Shen, Y.*; Zhang, X.*; Hao, Y.*; Feng, Y.*; Shen, S.*; He, Z.*; Pan, B.*; Wang, W.*; et al.
Physical Review Letters, 122(21), p.217003_1 - 217003_5, 2019/05
被引用回数：7 パーセンタイル：46.81(Physics, Multidisciplinary)We report neutron scattering measurements of single-crystalline YFeGe in the normal state, which has the same crystal structure as the 122 family of iron pnictide superconductors. YFeGe does not exhibit long-range magnetic order but exhibits strong spin fluctuations. Like the iron pnictides, YFeGe displays anisotropic stripe-type antiferromagnetic spin fluctuations at (
). More interesting, however, is the observation of strong spin fluctuations at the in-plane ferromagnetic wave vector (
). These ferromagnetic spin fluctuations are isotropic in the (
) plane, whose intensity exceeds that of stripe spin fluctuations. Both the ferromagnetic and stripe spin fluctuations remain gapless down to the lowest measured energies. Our results naturally explain the absence of magnetic order in YFeGe and also imply that the ferromagnetic correlations may be a key ingredient for iron-based materials.
Zhao, Q.*; 樽田 泰宜; 小林 重人*; 橋本 敬*
知識共創(インターネット), 8, p.V 13_1 - V 13_2, 2018/08
Erikson(1989)は心理社会的な視点で、ライフサイクル理論という人間の発達課題についての理論を提唱している。そこでは成人中期に、ジェネラティビティという世代継承性という課題があるという。「世代継承」とは、次世代に知識や情報を伝承するものである。この際、次世代への関心を持つことや関与するという意識は重要であり、例えば、子育てのみならず組織や社会そのものを育成することも含まれる概念である。「ふげん」は、2003年に原子炉の運転を終了し国の認可を受けて廃止措置に移行しているが、職員がこれまで培ってきた多くの技術や知識は、これまでの「運転」とは異なる業務が含まれる。今後、多くの知識等を持った職員は定年退職を迎えるため、それらの継承も課題となる。例えば、世代継承性が向上しない場合は"停滞性"という後ろ向きの課題が生じる。こうした因子は廃止措置おいても重要になると考えられる。そこで、本研究では、原子力発電施設の職員の世代継承性という社会心理的な課題を向上させる仕組みについて考察することを目的とする。
Liu, X.-H.*; 岡 眞; Zhao, Q.*
Physics Letters B, 753, p.297 - 302, 2016/02
被引用回数：101 パーセンタイル：98.61(Astronomy & Astrophysics)異常三角特異性(ATS)の性質と様々なハドロン生成過程における観測可能性とを検討した。最近観測された閾値付近に見られるハドロン状態の性質を理解する上で異常三角特異性が重要であることを示した。異常三角特異性と純粋にダイナミカルな極として現れる状態を区別する方法を議論した。
Deng, Z.*; Zhao, K.*; Gu, B.; Han, W.*; Zhu, J. L.*; Wang, X. C.*; Li, X.*; Liu, Q. Q.*; Yu, R. C.*; 後神 達郎*; et al.
Physical Review B, 88(8), p.081203_1 - 081203_5, 2013/08
被引用回数：77 パーセンタイル：91.56(Materials Science, Multidisciplinary)We report the discovery of a diluted magnetic semiconductor, Li(Zn,Mn)P, in which charge and spin are introduced independently via lithium off-stoichiometry and the isovalent substitution of Mn
for Zn, respectively. Isostructural to (Ga,Mn)As, Li(Zn,Mn)P was found to be a 
-type ferromagnetic semiconductor with excess lithium providing charge doping. First-principles calculations indicate that excess Li is favored to partially occupy the Zn site, leading to hole doping. Ferromagnetism with Curie temperature up to 34 K is achieved while the system still shows semiconducting transport behavior.
