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Zhao, X.*; Zhang, Z.*; 服部 高典; Wang, J.*; Li, L.*; Jia, Y.*; Li, W.*; Xue, J.*; Fan, X.*; Song, R.*; et al.
Nature Communications (Internet), 16, p.7713_1 - 7713_8, 2025/08
熱効果は、固体状態の冷凍技術の一つの解決策の基盤を成すもので、通常は固体状態の相転移付近で発生し、冷凍温度範囲が限定されている。ここでは、前例のない概念である「全温度帯バロカロリック効果」を導入し実現する。すなわち、KPF
において77.5Kから300Kの極めて広い温度範囲(潜在的に4Kまで)で観測される顕著なバカカロリック効果である。この温度範囲は、一般的な室温、液体窒素、液体水素、液体ヘリウムの冷却領域をカバーしている。直接測定されたバーカロリック断熱温度変化は、250MPaの圧力を解放した際に、室温で12K、77.5Kで2.5Kに達する。この効果は、圧力依存性の中性子粉末回折、ラマン散乱解析、第一原理計算により示されるように、菱面体高圧相への持続的な相転移に起因する。構造的不安定性を考慮した熱力学的エネルギーランドスケープを記述する。この独自の全温度帯バロカロリック効果は、従来の多段式シナリオを超えた、高度に適用可能な固体状態冷凍技術への新たなアプローチを提供する。
magnetic orderings in a triangular lattice; Implications for multi- orderings in general two-dimensional latticesPark, P.*; Cho, W.*; Kim, C.*; An, Y.*; 飯田 一樹*; 梶本 亮一; Matin, S.*; Zhang, S.-S.*; Batista, C. D.*; Park, J.-G.*
Physical Review X, 15(3), p.031032_1 - 031032_29, 2025/07
Multi- magnetic structures on two-dimensional (2D) lattices provide a key route to realizing topological physics in 2D magnetism. A major experimental challenge is to unambiguously confirm their formation by excluding the possibility of topologically trivial multi-domain single- or double- magnetic orders, which cannot be distinguished using conventional diffraction techniques. Here, we propose that long-wavelength spin dynamics offers a universal diagnostic for triangular lattices: triple- orders that preserve rotational symmetry and single- or double- orders that break it exhibit qualitatively distinct anisotropies in their Goldstone mode velocities, stemming from fundamental differences in their underlying spin configurations. We validate this concept using the metallic triangular-lattice antiferromagnet Co
TaS
, which hosts both a stripe-type single- state and a triple- tetrahedral ordering at different temperatures. Using inelastic neutron-scattering and spin dynamics simulations, we first refine the spin Hamiltonian by fitting the paramagnetic excitation spectra, allowing us to develop an unbiased model independent of magnetic ordering. We then show that the observed velocity profiles of the Goldstone modes agree with the high-temperature model's predictions: markedly anisotropic for the single- phase and near isotropic for the triple- phase. Importantly, this contrast persists across various exchange parameters, highlighting its model-independent nature and suggesting potential applicability to other 2D lattice systems. Beyond the long-wavelength regime, we present a substantial discrepancy between the measured and simulated magnon spectra exclusively in the triple- phase. We attribute this discrepancy to magnon energy renormalization arising from order-of-magnitude-enhanced magnon-magnon interactions in the triple- phase, due to its noncollinear configuration. This work provides universal insight into the dynamical properties of topological multi- magnetic orderings in 2D lattice structures, offering a broadly applicable diagnostic to distinguishing them from topologically trivial single- or double- counterparts. The unequivocal confirmation of the triple- structure in CoTaS further establishes it as a prominent material platform for exploring topological spin textures in the genuine 2D limit.
Brumm, S.*; Gabrielli, F.*; Sanchez Espinoza, V.*; Stakhanova, A.*; Groudev, P.*; Petrova, P.*; Vryashkova, P.*; Ou, P.*; Zhang, W.*; Malkhasyan, A.*; et al.
Annals of Nuclear Energy, 211, p.110962_1 - 110962_16, 2025/02
被引用回数：6 パーセンタイル：96.16(Nuclear Science & Technology)The completed Horizon-2020 project on "Management and Uncertainties of Severe Accidents (MUSA)" has reviewed uncertainty sources and Uncertainty Quantification methodology for the purpose of assessing Severe Accidents (SA). The key motivation of the project has been to bring the advantages of the Best Estimate Plus Uncertainty approach to the field of Severe Accident. The applications brought together a large group of participants that set out to apply uncertainty analysis (UA) within their field of SA modelling expertise, in particular reactor types, but also SA code used (ASTEC, MELCOR, etc.), uncertainty quantification tools used (DAKOTA, RAVEN, etc.), detailed accident scenarios, and in some cases SAM actions. This paper synthesizes the reactor-application work at the end of the project. Analyses of 23 partners are sorted into different categories, depending on whether their main goal is/are (i) uncertainty bands of simulation results; (ii) the understanding of dominating uncertainties in specific sub-models of the SA code; (iii) improving the understanding of specific accident scenarios, with or without the application of SAM actions; or, (iv) a demonstration of the tools used and developed, and of the capability to carry out an uncertainty analysis in the presence of the challenges faced. The partners' experiences made during the project have been evaluated and are presented as good practice recommendations. The paper ends with conclusions on the level of readiness of UA in SA modelling, on the determination of governing uncertainties, and on the analysis of SAM actions.
neutron imaging and diffraction analysis revealing spatial lithiation phase evolution in an ultra-thick graphite electrodeStrobl, 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
被引用回数：0 パーセンタイル：0.00Energy-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 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
C
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.
Liu, P.-F.*; Li, X.*; Li, J.*; Zhu, J.*; Tong, Z.*; 古府 麻衣子*; 楡井 真実; Xu, J.*; Yin, W.*; Wang, F.*; et al.
National Science Review, 11(12), p.nwae216_1 - nwae216_10, 2024/12
被引用回数：13 パーセンタイル：93.65(Multidisciplinary Sciences)Crystalline solids exhibiting inherently low lattice thermal conductivity (
) are of great importance in applications such as thermoelectrics and thermal barrier coatings. However, cannot be arbitrarily low and is limited by the minimum thermal conductivity related to phonon dispersions. In this work, we report the liquid-like thermal transport in a well-ordered crystalline CsAg
Te
, which exhibits an extremely low value of 
0.18 Wm
K. On the basis of first-principles calculations and inelastic neutron scattering measurements, we find that there are lots of low-lying optical phonon modes at 3.1 meV hosting the avoided-crossing behavior with acoustic phonons. These strongly localized modes are accompanied by weakly bound rattling Ag atoms with thermally induced large amplitudes of vibrations. Using the two-channel model, we demonstrate that coupling of the particle-like phonon modes and the heat-carrying wave-like phonons is essential for understanding the low , which is heavily deviated from the 
temperature dependence of the standard Peierls theory. In addition, our analysis indicates that the soft structural framework with liquid-like motions of the fluctuating Ag atoms is the underlying cause that leads to the suppression of the heat conduction in CsAgTe. These factors synergistically account for the ultralow value. Our results demonstrate that the liquid-like heat transfer could indeed exist in a well-ordered crystal.
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
被引用回数：2 パーセンタイル：62.38(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)
C
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.
Zhang, Z.*; 服部 高典; Song, R.*; Yu, D.*; Mole, R.*; Chen, J.*; He, L.*; Zhang, Z.*; Li, B.*
Journal of Applied Physics, 136(3), p.035105_1 - 035105_8, 2024/07
被引用回数：2 パーセンタイル：48.66(Physics, Applied)バロカロリック材料を用いた固体冷凍は、環境に優しく高効率であるため、過去10年間にわたり世界的に注目されてきた。ここでは、室温付近で立方晶から菱面体晶への相転移を起こすヘキサフルオロ燐酸ナトリウム(NaPF)とヘキサフルオロ砒酸ナトリウム(NaAsF)における巨大バロカロリック効果を報告する。われわれは中性子粉末回折により、NaPFの低温相の構造が空間群R
の菱面体構造であることを明らかにした。NaPFとNaAsFには3つのラマン振動モード(F
, E
, A
)が存在する。相転移温度はNaPF及びNaAsFにおいてそれぞれdT
/dP=250K/GPa及び310K/GPaの割合で圧力とともに変化する。NaPFとNaAsFの圧力誘起エントロピー変化は、それぞれ約45.2JkgKと35.6JkgKと決定された。飽和駆動圧力は約40MPaであった。高圧下の中性子粉末回折から、バロカロリック効果は立方晶から菱面体晶への圧力誘起相転移に関係していることが示唆された。
Liao, J.*; Huang, Z.*; Shangguan, Y.*; Zhang, B.*; Cheng, S.*; Xu, H.*; 梶本 亮一; 蒲沢 和也*; Bao, S.*; Wen, J.*
Physical Review B, 109(22), p.224411_1 - 224411_10, 2024/06
被引用回数：0 パーセンタイル：0.00(Materials Science, Multidisciplinary)Antiferromagnetic van der Waals family 
P
( = Fe, Mn, Co, and Ni; 
= S and Se) have attracted significant research attention due to the possibility of realizing long-range magnetic order down to the monolayer limit. Here, we perform inelastic neutron scattering measurements on single-crystal samples of MnPSe, a member of the P family, to study the spin dynamics and determine the effective spin model. The excited magnon bands are well characterized by a spin model, which includes a Heisenberg term with three intraplane exchange parameters (
meV, 
meV, 
meV) and one interplane parameter (
meV), and an easy-plane single-ion anisotropy term (
meV). Additionally, we observe the intersection of the magnon and phonon bands but no anomalous spectral features induced by the formation of magnon-phonon hybrid excitations at the intersecting region. We discuss possible reasons for the absence of such hybrid excitations in MnPSe.
Baccou, J.*; Glantz, T.*; Ghione, A.*; Sargentini, L.*; Fillion, P.*; Damblin, G.*; Sueur, R.*; Iooss, B.*; Fang, J.*; Liu, J.*; et al.
Nuclear Engineering and Design, 421, p.113035_1 - 113035_16, 2024/05
被引用回数：6 パーセンタイル：94.73(Nuclear Science & Technology)In the Best-Estimate Plus Uncertainty (BEPU) framework, the use of best-estimate code requires to go through a Verification, Validation and Uncertainty Quantification process (VVUQ). The relevance of the experimental data in relation to the physical phenomena of interest in the VVUQ process is crucial. Adequacy analysis of selected experimental databases addresses this problem. The outcomes of the analysis can be used to select a subset of relevant experimental data, to encourage designing new experiments or to drop some experiments from a database because of their substantial lack of adequacy. The development of a specific transparent and reproducible approach to analyze the relevance of experimental data for VVUQ still remains open and is the topic of this contribution. In this paper, the concept of adequacy initially introduced in the OECD/NEA SAPIUM (Systematic APproach for model Input Uncertainty quantification Methodology) activity is formalized. It is defined through two key properties, called representativeness and completeness, that allows considering the multifactorial dimension of the adequacy problem. A new systematic approach is then proposed to analyze the adequacy of a set of experimental databases. It relies on the introduction of two sets of criteria to characterize representativeness and completeness and on the use of multi-criteria decision analysis method to perform the analysis. Finally, the approach is applied in the framework of the new OECD/NEA ATRIUM activity which includes a set of practical IUQ exercises in thermal-hydraulics to test the SAPIUM guideline in determining input uncertainties and forward propagating them on an application case. It allows evaluating the adequacy of eight experimental databases coming from the Super Moby-dick, Sozzi-Sutherland and Marviken experiments and identifying the most adequate ones.
Guo, B.*; Chen, H.*; Chong, Y.*; Mao, W.; Harjo, S.; Gong, W.; Zhang, Z.*; Jonas, J. J.*; 辻 伸泰*
Acta Materialia, 268, p.119780_1 - 119780_11, 2024/04
被引用回数：10 パーセンタイル：91.50(Materials Science, Multidisciplinary)This paper focused on the characterization and mechanism of the dynamic transformation from the alpha to beta phase during the hot deformation of Ti-6Al-4V alloy and pure titanium. The investigation employed in-situ neutron diffraction and atomistic simulations for a comprehensive understanding of the process. Dynamic transformations were observed during deformation of the Ti-6Al-4V alloy and pure titanium below the beta transus temperatures. During isothermal holding after unloading, the in-situ neutron diffraction results for Ti-6Al-4V and pure titanium indicated a sluggish reverse transformation from the beta to alpha phase. The mechanism of dynamic transformation was explored through in-situ neutron diffraction and atomistic simulations, which revealed twofold effects of deformation on dynamic transformation. Firstly, deformation led to a significant rise in the Gibbs energy of the alpha phase relative to the beta phase, expanding the beta phase region and diminishing the alpha phase region. Secondly, deformation lowered the energy barriers associated with dynamic transformation, facilitating the activation of dynamic transformation more readily than in the equilibrium state before deformation.
Li, X.*; Zhu, R.*; Xin, J.*; Luo, M.*; Shang, S.-L.*; Liu, Z.-K.*; Yin, C.*; 舟越 賢一*; Dippenaar, R. J.*; 肥後 祐司*; et al.
CALPHAD; Computer Coupling of Phase Diagrams and Thermochemistry, 84, p.102641_1 - 102641_6, 2024/03
被引用回数：0 パーセンタイル：0.00(Thermodynamics)The phase transformations and pressure-volume dependencies of the Ti-45Al alloy with respect to pressure have been investigated by means of in-situ observation using multi anvil-type high-pressure devices and synchrotron radiation. Under hydrostatic compression from 0 to 10.1 GPa, about 2.3 vol. % of 
transforms continuously to 
2. Lattice parameters as well as volume fractions of these two phases have been determined as a function of pressure. Bulk moduli estimated using Birch-Murnaghan's equation of state are 148 GPa for the phase, 138 GPa for the 2 phase, and 149 GPa for their two-phase mixture of Ti-45Al alloy. First-principles have also applied to investigate bulk moduli of two single phases, and the deviation between calculations and measurements is discussed and attributed to mainly phase transformation. The presently study provides useful insights into thermodynamics of 2 and phases under high pressure.
Yu, C.*; 川北 至信; 菊地 龍弥*; 古府 麻衣子*; 本田 孝志*; Zhang, Z.*; Zhang, Z.*; Liu, Y.*; Liu, S. F.*; Li, B.*
Journal of Physical Chemistry Letters (Internet), 15(1), p.329 - 338, 2024/01
The atomic dynamic behaviors of formamidinium lead iodide [HC(NH)PbI] are critical for understanding and improving photovoltaic performances. However, they remain unclear. Here, we investigate the structural phase transitions and the reorientation dynamics of the formamidinium cation [HC(NH)
, FA
] of FAPbI using neutron scattering techniques. Two structural phase transitions occur with decreasing temperature, from cubic to tetragonal phase at 285 K and then to another tetragonal at 140 K, accompanied by gradually frozen reorientation of FA cations. The nearly isotropic reorientation in the cubic phase is suppressed to reorientation motions involving a two-fold (C) rotation along the 
axis and a four-fold (C
) rotation along the C-H axis in the tetragonal phase, and eventually to local disordered motion as a partial C along the C-H axis in another tetragonal phase, thereby indicating an intimate interplay between lattice and orientation degrees of freedom in the hybrid perovskite materials. The present complete atomic structure and dynamics provide a solid standing point to understand and then improve photovoltaic properties of organic-inorganic hybrid perovskites in the future.
-Ti alloyZhang, B.*; Xin, S.*; Huang, M.*; Mao, W.; Jia, W.*; Li, Q.*; Li, S.*; Zhang, S.*; Mao, C.*
Materials Science & Engineering A, 890, p.145898_1 - 145898_7, 2024/01
被引用回数：0 パーセンタイル：0.00(Nanoscience & Nanotechnology)本研究では、高Zr--Ti合金の変形温度を300Kから77Kに下げると回復ひずみが2.25%から5.5%に大幅に増加することを報告した。この合金の超弾性は77Kにおいて粒径に依存しないことがわかった。その結果、粗粒試料は77Kで超微粒試料とほぼ同じ超弾性を示すことがわかった。変形誘起マルテンサイト変態と転位すべりの相対的な容易さは77Kで大きく変化し、転位すべりは強く抑制され、超弾性に対する結晶粒の微細化の影響は影を潜めた。
TaSPark, P.*; Cho, W.*; Kim, C.*; An, Y.*; Kang, Y.-G.*; Avdeev, M.*; Sibille, R.*; 飯田 一樹*; 梶本 亮一; Lee, K. H.*; et al.
Nature Communications (Internet), 14, p.8346_1 - 8346_9, 2023/12
被引用回数：23 パーセンタイル：87.00(Multidisciplinary Sciences)The triangular lattice antiferromagnet (TLAF) has been the standard paradigm of frustrated magnetism for several decades. The most common magnetic ordering in insulating TLAFs is the 120
structure. However, a new triple- chiral ordering can emerge in metallic TLAFs, representing the short wavelength limit of magnetic skyrmion crystals. We report the metallic TLAF CoTaS as the first example of tetrahedral triple- magnetic ordering with the associated topological Hall effect (non-zero 
). We also present a theoretical framework that describes the emergence of this magnetic ground state, which is further supported by the electronic structure measured by angle-resolved photoemission spectroscopy. Additionally, our measurements of the inelastic neutron scattering cross section are consistent with the calculated dynamical structure factor of the tetrahedral triple- state.
Lloveras, P.*; Zhang, Z.*; Zeng, M.*; Barrio, M.*; 川北 至信; Yu, D.*; Lin, S.*; Li, K.*; Moya, X.*; Tamarit, J.-L.*; et al.
Barocaloric Effects in the Solid State; Materials and methods, p.7_1 - 7_30, 2023/10
被引用回数：232 パーセンタイル：99.37(Multidisciplinary Sciences)「固体状態における圧力熱量効果」と題する電子ブックの第一章として、様々な柔粘性結晶が紹介されている。柔粘性結晶における圧力熱量反応を決定する方法、その熱力学的な起源、中性子準弾性散乱からの分光学的洞察、柔粘性結晶の応用などが解説されている。
Yang, D. S.*; Wu, Y.*; Kanatzidis, E. E.*; Avila, R.*; Zhou, M.*; Bai, Y.*; Chen, S.*; 関根 由莉奈; Kim, J.*; Deng, Y.*; et al.
Materials Horizons, 10(11), p.4992 - 5003, 2023/09
被引用回数：12 パーセンタイル：81.27(Chemistry, Multidisciplinary)本論文では、ハード及びソフトハイブリッド材料システムでの3Dプリントによって形成されたマイクロ流体ネットワーク、統合バルブ、およびマイクロスケール光学キュベットにより、汗成分に対してその場で分光および蛍光分析した成果を紹介する。一連の試験により、これらのマイクロキュベットシステムが汗中の銅、塩化物、グルコースの濃度と汗のpHを実験室レベルの精度と感度で評価できることが実証された。
Bao, S.*; Gu, Z.-L.*; Shangguan, Y.*; Huang, Z.*; Liao, J.*; Zhao, X.*; Zhang, B.*; Dong, Z.-Y.*; Wang, W.*; 梶本 亮一; et al.
Nature Communications (Internet), 14, p.6093_1 - 6093_9, 2023/09
被引用回数：21 パーセンタイル：94.13(Multidisciplinary Sciences)Magnon polarons are novel elementary excitations possessing hybrid magnonic and phononic signatures, and are responsible for many exotic spintronic and magnonic phenomena. Despite long-term sustained experimental efforts in chasing for magnon polarons, direct spectroscopic evidence of their existence is hardly observed. Here, we report the direct observation of magnon polarons using neutron spectroscopy on a multiferroic FeMoO
possessing strong magnon-phonon coupling. Specifically, below the magnetic ordering temperature, a gap opens at the nominal intersection of the original magnon and phonon bands, leading to two separated magnon-polaron bands. Each of the bands undergoes mixing, interconverting and reversing between its magnonic and phononic components. We attribute the formation of magnon polarons to the strong magnon-phonon coupling induced by Dzyaloshinskii-Moriya interaction. Intriguingly, we find that the band-inverted magnon polarons are topologically nontrivial. These results uncover exotic elementary excitations arising from the magnon-phonon coupling, and offer a new route to topological states by considering hybridizations between different types of fundamental excitations.
Esser, S. P.*; Rahlff, J.*; Zhao, W.*; Predl, M.*; Plewka, J.*; Sures, K.*; Wimmer, F.*; Lee, J.*; Adam, P. S.*; McGonigle, J.*; et al.
Nature Microbiology (Internet), 8(9), p.1619 - 1633, 2023/09
被引用回数：9 パーセンタイル：79.43(Microbiology)CRISPR-Cas systems defend prokaryotic cells from viruses, plasmids, and other mobile genetic elements. Capitalizing on multi-omics approaches, we show here that the CRISPR-Cas systems of uncultivated archaea also play an integral role in mitigating potentially detrimental interactions with episymbionts. A comprehensive analysis of CRISPR-Cas-based infection histories revealed that uncultivated deep-subsurface archaeal primary-producers defend themselves from archaeal episymbionts of the DPANN superphylum of archaea, some of which are known to fuse their membranes with their host. We show that host cells counter these attacks by deploying one of two CRISPR-Cas systems (type I-B and type III-A) to target and disrupt essential genes in the episymbiont. However, genome-scale modeling of metabolic interactions between two deep subsurface host-symbiont systems revealed that host cells also benefit from the symbionts via metabolic complementation. We speculate that populations of these uncultivated archaeal episymbionts are currently transitioning from a parasitic lifestyle to one of mutualism, as must have occurred in countless mutualistic systems known today. By expanding our analysis to thousands of archaeal genomes, we conclude that CRISPR-Cas mediated resistance to archaeal episymbiosis evolved independently in various archaeal lineages and may be a wide-spread evolutionary phenomenon.
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：92.44(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.
neutron diffraction study on the deformation behavior of the plastic inorganic semiconductor AgSWang, Y.*; Gong, W.; 川崎 卓郎; Harjo, S.; Zhang, K.*; Zhang, Z. D.*; Li, B.*
Applied Physics Letters, 123(1), p.011903_1 - 011903_6, 2023/07
被引用回数：4 パーセンタイル：44.19(Physics, Applied)Bulk AgS is a plastic inorganic semiconductor at room temperature. It exhibits a compressive strain greater than 50%, which is highly different from brittle conventional counterparts, such as silicon. Here, we present the experimental investigation of the deformation behavior in a plastic inorganic semiconductor AgS using 
neutron diffraction during compressive deformation at room and elevated temperatures. At room temperature, the lattice strain partitioning among 
-orientated grain families could be responsible for the significant work-hardening behavior in the bulk AgS with a monoclinic structure. The rapid accumulation of lattice defects and remarkable development of the deformation texture suggest that dislocation slip promotes plasticity. At 453 K, a monoclinic phase transforms into a body-centered cubic phase. A stress plateau appears at -4.8 MPa, followed by a rehardening state. The deformation mode of bulk AgS at the initial stage is likely attributable to the migration of silver ions, and as strain increases, it is closer to that of room temperature, leading to rehardening.
