Acta Materialia最新文献_第3页

Three-dimensional crystallographic and local variant configuration analysis of lath martensite in medium-carbon steel 中碳钢板条马氏体三维结晶学及局部变构分析

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-02-03 DOI: 10.1016/j.actamat.2026.121981

Akinobu Shibata , Goro Miyamoto , Shigekazu Morito , Akiko Nakamura , Taku Moronaga , Houichi Kitano , Ivan Gutierrez-Urrutia , Toru Hara

The microstructures and crystallographic features of lath martensite in a medium-carbon steel were investigated using focused ion beam-scanning electron microscopy serial sectioning and automated crystallographic orientation mapping in transmission electron microscopy techniques. The analysis revealed that, despite the complex and interwoven overall morphology, individual laths possess well-defined, plate-like shapes. Habit plane / lath boundary plane orientations determined by two-surface trace analysis spanned a range from (2 5 2)_A to (2 9 5)_A in the austenite coordinate system and were centered around (3 8 1)_M in the martensite coordinate system. These results are consistent with predictions from the phenomenological theory of martensitic crystallography incorporating double lattice-invariant deformations and a high degree of tetragonality. Crystallographic variant analysis showed pairing tendencies among variants sharing parallel close-packed planes, along with the presence of nanoscale twin-related domains distinct from typical (1 1 2)_M transformation twins. These domains were interpreted as twin-orientation-related intralath structures that formed ahead of the longitudinal growth front of a martensite plate and were subsequently embedded by its lateral growth. Micromechanics calculations further suggested that stress-induced variant selection, enhanced by high tetragonality, plays a critical role in the preferential formation of these twin-orientation-related intralath structures. Although the lath has traditionally been regarded as the smallest structural unit, detailed characterization of a twin-orientation-related intralath structure reveals an additional level of hierarchy, distinct from conventional defect substructures, fundamentally redefining the established microstructural concept of lath martensite.

采用聚焦离子束扫描电镜、连续切片和透射电镜自动晶体取向成像技术研究了中碳钢板条马氏体的显微组织和晶体学特征。分析显示，尽管复杂和交织的整体形态，个别板条具有明确的，板状形状。两面示踪分析确定的习惯面/板条边界面取向在奥氏体坐标系下从（2 5 2）a到（2 9 5）a之间，在马氏体坐标系下以（3 8 1）M为中心。这些结果与马氏体晶体学的现象学理论的预测一致，包括双晶格不变变形和高度的四方性。晶体变异体分析显示，在共享平行密排平面的变异体之间存在配对趋势，同时存在与典型的（1 1 2）M相变孪晶不同的纳米尺度孪晶相关结构域。这些结构域被解释为与双取向相关的板内结构，它们形成于马氏体板块纵向生长前缘之前，随后被其横向生长所嵌入。微观力学计算进一步表明，高四方性增强的应力诱导变异选择在这些与双取向相关的板内结构的优先形成中起着关键作用。尽管板条传统上被认为是最小的结构单元，但与双取向相关的板条内结构的详细特征揭示了与传统缺陷子结构不同的额外层次，从根本上重新定义了板条马氏体的既定微观结构概念。

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引用次数: 0

Discovery and characterization of a silicon aluminum scandate (SAS) material 硅铝酸盐（SAS）材料的发现与表征

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-20 DOI: 10.1016/j.actamat.2026.121949

Kevin Yu , Jamesa Stokes , Kunal K. Jha , Bryan Harder , Hosea M. Nelson , Katherine T. Faber

A newly discovered doped silicon aluminum scandate (SAS) phase was successfully isolated and synthesized. Microcrystal electron diffraction was employed to determine the doped SAS crystal structure, revealing a triclinic (P

\overline{1}

) unit cell with the nominal formula Si₂Al₂Sc₁₄O₂₈ with minority dopants of CaO, MgO, Fe₂O₃, and TiO₂. Powder X-ray diffraction and Rietveld refinement confirmed the structure of the doped SAS material. Electron-probe microanalysis and solid-state nuclear magnetic resonance were used to better understand the composition and local structure of the doped SAS phase. The results indicated that there are extensive cation substitutions within the doped SAS material. Differential thermal analysis on doped SAS demonstrated that the material is thermally stable up to 2150 °C, suggesting potential for refractory applications. Additional characterization, enabled by the solved structure of doped SAS, focused on relevant properties for refractory materials. The thermal expansion behavior of the doped SAS material was evaluated using high-temperature, in situ X-ray diffraction, while the reaction pathway for SAS formation was determined using a combination of high-temperature X-ray diffraction and annealing experiments. Ultimately, this study defines the structure, composition, and thermal behavior of the doped SAS material, while also highlighting the utility of microcrystal electron diffraction for structure determination of complex oxide phases.

成功地分离并合成了一种新发现的掺杂硅铝酸盐（SAS）相。采用微晶电子衍射法测定了掺杂的SAS晶体结构，得到了一个三斜（P1¯）的晶胞，其公称公式为Si2Al2Sc14O28，少量掺杂了CaO、MgO、Fe2O3和TiO2。粉末x射线衍射和Rietveld细化证实了掺杂SAS材料的结构。利用电子探针微分析和固态核磁共振技术更好地了解掺杂SAS相的组成和局部结构。结果表明，掺杂的SAS材料中存在广泛的阳离子取代。对掺杂SAS的差热分析表明，该材料在2150°C下热稳定，表明其具有耐火材料应用的潜力。通过求解掺杂SAS的结构，进一步表征了耐火材料的相关性质。利用高温原位x射线衍射评价了掺杂SAS材料的热膨胀行为，同时利用高温x射线衍射和退火实验相结合的方法确定了SAS形成的反应途径。最后，本研究确定了掺杂SAS材料的结构、组成和热行为，同时也强调了微晶电子衍射在复杂氧化相结构测定中的应用。

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引用次数: 0

Insights into the preferential intergranular oxidation mechanism of 316L austenitic stainless steel exposed to oxygen saturated lead-bismuth eutectic (LBE) 饱和氧铅铋共晶（LBE）下316L奥氏体不锈钢晶间优先氧化机制的研究

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-23 DOI: 10.1016/j.actamat.2026.121962

Wenhao Zhang , Wen Wang , Jibo Tan , Xing Gong , En-Hou Han , Wenjun Kuang

The preferential intergranular oxidation (PIO) behavior of 316L stainless steel (SS) exposed to oxygen saturated Lead-bismuth eutectic (LBE) at 550 °C was investigated. PIO occurred at both random high angle grain boundaries (RHABs) and coherent twin boundaries (CTBs), with RHABs exhibiting deeper intergranular oxidation. The high diffusivity of RHAB supports rapid diffusion of Cr toward the PIO front, leading to the formation of extensive polycrystalline Cr₂O₃. In contrast, only a thin flake of Cr₂O₃ was observed at the oxidation front of CTB. Diffusion induced grain boundary migration (DIGM) zones were observed not only at RHAB oxidation front, but also at CTB front. Driven by Ni dissolution through intergranular pores, the DIGM zone further degrades into fragmented Ni-enriched particles along RHAB. Nano-pores, formed via Ni selective leaching and Fe outward diffusion, were observed in intergranular oxides at the oxidation fronts of both RHAB and CTB. These intergranular pores constitute rapid diffusion paths, significantly aggravating PIO.

研究了316L不锈钢（SS）在550℃饱和氧铅铋共晶（LBE）下的优先晶间氧化（PIO）行为。PIO发生在随机高角晶界（RHABs）和相干孪晶界（CTBs），其中RHABs表现出更深的晶间氧化。RHAB的高扩散率支持Cr向PIO前沿快速扩散，导致形成广泛的Cr2O3多晶。相比之下，在CTB的氧化前沿只观察到一层薄薄的Cr2O3。扩散诱导晶界迁移（DIGM）区不仅存在于RHAB氧化锋，也存在于CTB氧化锋。在Ni通过晶间孔隙溶解的驱动下，DIGM区沿RHAB进一步降解为破碎的富Ni颗粒。在RHAB和CTB氧化前沿的晶间氧化物中均观察到Ni选择性浸出和Fe向外扩散形成的纳米孔。这些粒间孔隙构成快速扩散路径，显著加重PIO。

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引用次数: 0

Boosting Strength and ductility of Ti-6Al-4V alloy via millisecond-level electric treatment induced heterogeneous nanostructures 微细电处理诱导非均相纳米结构提高Ti-6Al-4V合金的强度和延展性

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-29 DOI: 10.1016/j.actamat.2026.121976

Jiajun Zhang , Jiajun Wang , Yu Yan , Fei Wang , Jian Wang , Jianjiang Zhao , Yunmin Chen , Yang Ju , Hua Wei

Introducing nanoscale structures into metallic materials is a well-established strategy to achieve a superior strength–ductility balance, yet it often relies on complex, multi-step thermo-mechanical processing. Here, we demonstrate a millisecond-scale electric heating treatment as a simple and effective approach to embed nanostructures in hot-forged Ti-6Al-4V alloys, simultaneously enhancing tensile strength (∼1240.5 MPa) and fracture elongation (∼15.5%). Unlike conventional annealing, the process combines ultrafast localized Joule heating with rapid cooling. The transient high temperatures accelerate short-range elemental diffusion and promote the formation of additional β-Ti clusters. Meanwhile, the brief heating duration suppresses long-range diffusion, stabilizes the α-Ti matrix, and drives the formation of abundant heterogeneous nanostructures. The resulting alternant nanoscale α′-Ti martensite and β-Ti lamellae with distinct misorientations strengthen the alloy, while <c+a>-type dislocations activate at interphase boundaries complement <a>-type slip and enhance plastic flow. Furthermore, localized Joule heating facilitates dislocation depinning and slip transmission, contributing to improved ductility. Overall, ultrafast electric heating provides an effective pathway for integrating nano-lamellar architectures, offering a promising strategy for microstructural engineering in advanced metallic materials.

在金属材料中引入纳米结构是实现强度-延性平衡的一种行之有效的策略，但它往往依赖于复杂的、多步骤的热机械加工。在这里，我们展示了毫秒级的电加热处理作为一种简单有效的方法，在热锻Ti-6Al-4V合金中嵌入纳米结构，同时提高抗拉强度（~ 1240.5 MPa）和断裂伸长率（~ 15.5%）。与传统退火不同，该工艺结合了超快局部焦耳加热和快速冷却。瞬态高温加速了元素的短程扩散，促进了额外β-Ti簇的形成。同时，较短的加热时间抑制了α-Ti基体的远距离扩散，稳定了α-Ti基体，驱动了丰富的非均相纳米结构的形成。由此产生的纳米级α′-Ti马氏体和具有明显取向错的β-Ti片层交替强化了合金，而在相界处激活的<；c+a>；型位错补充了<；a>；型滑移，增强了塑性流动。此外，局部焦耳加热促进位错脱脱和滑移传递，有助于提高延展性。总之，超快电加热为集成纳米片层结构提供了有效的途径，为先进金属材料的微结构工程提供了一个有前途的策略。

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引用次数: 0

Structural origins of thermal expansion behavior in 2D materials 二维材料热膨胀行为的结构根源

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-22 DOI: 10.1016/j.actamat.2026.121956

Yang Yang , Guangya Li , Yixin Lin , Yan Chen , Hongxiang Zong , Xiangdong Ding , Xun-Li Wang , Jun Sun

Two-dimensional (2D) materials exhibit diverse thermal expansion behavior—with coefficients spanning a broad range from negative to positive values—fundamentally challenging our understanding of thermal expansion mechanisms and creating critical uncertainties in thermal stress prediction for next-generation devices. Despite numerous experimental measurements, the fundamental structural mechanisms underlying this remarkable variability remains elusive. Here, we resolve this longstanding puzzle through systematical molecular dynamics simulations of four representative 2D materials: hBN, PbTe, graphene, and MoS₂. Our simulations reveal that thermal expansion behavior is governed by the interplay between the intrinsic chemical bond thermal expansion and out-of-plane structural flexibility. This interplay enables 2D materials to achieve thermal expansion coefficients ranging from -15.0 × 10⁻⁶ K⁻¹ to +52.4 × 10⁻⁶ K⁻¹. Crucially, we demonstrate that thickness and lateral size effects arise exclusively through modulation of out-of-plane deformation freedom, while substrate interactions operate via a dual pathway that simultaneously constrains structural flexibility and modifies intrinsic bond behavior. Our findings culminate in a universal scaling relationship between area-specific bending rigidity and thermal expansion coefficients, providing the first predictive framework for 2D material thermal behavior.

二维（2D）材料表现出不同的热膨胀行为-系数跨越从负值到正值的广泛范围-从根本上挑战了我们对热膨胀机制的理解，并在下一代设备的热应力预测中产生了关键的不确定性。尽管进行了大量的实验测量，但这种显著变化背后的基本结构机制仍然难以捉摸。在这里，我们通过系统的分子动力学模拟四种代表性的二维材料：hBN， PbTe，石墨烯和MoS 2来解决这个长期存在的难题。我们的模拟表明，热膨胀行为是由固有化学键热膨胀和面外结构柔性之间的相互作用所控制的。这种相互作用使二维材料的热膨胀系数从-15.0 × 10⁻⁶K⁻¹到+52.4 × 10⁻⁶K⁻¹。至关重要的是，我们证明了厚度和横向尺寸效应仅通过调制面外变形自由产生，而基材相互作用通过双重途径同时限制结构灵活性和改变固有键行为。我们的研究结果最终得出了区域特定弯曲刚度和热膨胀系数之间的普遍标度关系，为二维材料热行为提供了第一个预测框架。

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引用次数: 0

Cross-scale heterogeneity enables strengthening and strain de-localization in a FeMnCoCr multi-principal element alloy 跨尺度非均质性使FeMnCoCr多主元素合金的强化和应变去局部化成为可能

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-02-05 DOI: 10.1016/j.actamat.2026.121991

H.Z. Pan , S. Jiang , Z.F. He , X.F. Chen , X.X. Dong , H. Zhou , N. Jia

Heterostructure design demonstrates great potential in overcoming the strength-ductility trade-off in materials. Here, a cross-scale heterostructure was constructed in the FeMnCoCr multi-principal element alloy by performing triaxial cyclic compression (TCC) on bulk alloy followed by short-time annealing (denoted as "Blocky" material). For comparison, thin slices extracted from the TCC-processed block were annealed (denoted as "Sliced" material). At the macroscopic scale of the Blocky material, a gradient distribution of recrystallization is formed from the surface to the core. The high-strain core contains 13.3–18.1% recrystallized grains with dense dislocations, while the low-strain subcenter has less recrystallized grains (11.6–14.5%) and lower dislocation density, leading to gradient microhardness and kernel average misorientation distributions. In contrast, the Sliced material shows 20.5–24.4% recrystallization at both positions and uniform microstructure. At the grain scale, in the Blocky material non-recrystallized regions hinder plastic deformation via dense dislocation cells, local chemical order (LCO) laths, deformation twins and 9R-mediated nano-twins, while the recrystallized regions act as soft domains. At the nanoscale, extensive LCO further impedes dislocation motion. This cross-scale heterogeneity induces significant hetero-deformation-induced strengthening. The subcenter and center of the Blocky material, as well as the recrystallized/non-recrystallized domains within each region, sequentially activate deformation mechanisms. This facilitates continuous strain transfer across sample and grain scales, suppressing localized necking. Persistent activation of dislocation slip, stacking faults, nano-twins and bidirectional transformation enables the material to achieve a high yield strength of 880 MPa and an impressive fracture strain of 36%. These findings provide new insights for designing high-performance heterogeneous metallic materials.

异质结构设计在克服材料的强度-延性权衡方面显示出巨大的潜力。本文通过对块状合金（块状材料）进行三轴循环压缩（TCC）并进行短时退火，在FeMnCoCr多主元素合金中构建了跨尺度异质结构。为了进行比较，从tcc加工块中提取的薄片进行退火（表示为“切片”材料）。在块状材料的宏观尺度上，从表面到核心形成了梯度的再结晶分布。高应变核心含有13.3 ~ 18.1%的再结晶晶粒，位错密集，而低应变亚中心含有较少的再结晶晶粒（11.6 ~ 14.5%），位错密度较低，导致显微硬度梯度和仁平均位错分布。切片后的材料在两个位置均有20.5 ~ 24.4%的再结晶，且组织均匀。在晶粒尺度上，块状材料中的非再结晶区通过密集的位错胞、局部化学有序（LCO）条、变形孪晶和9r介导的纳米孪晶阻碍塑性变形，而再结晶区则作为软畴。在纳米尺度上，广泛的LCO进一步阻碍了位错运动。这种跨尺度非均质性导致了显著的异质变形诱导强化。块状材料的亚中心和中心以及每个区域内的再结晶/非再结晶区域依次激活变形机制。这有利于在样品和晶粒尺度上的连续应变传递，抑制局部颈缩。位错滑移、层错、纳米孪晶和双向相变的持续激活使材料获得了高达880 MPa的屈服强度和高达36%的断裂应变。这些发现为高性能非均质金属材料的设计提供了新的见解。

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引用次数: 0

Hydride precipitation stresses governing autocatalytic nucleation and stacking interaction in zirconium alloys: Phase-field modeling and HR-EBSD determination 锆合金中控制自催化成核和堆积相互作用的氢化物沉淀应力：相场建模和HR-EBSD测定

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-20 DOI: 10.1016/j.actamat.2026.121951

Runhao Zhang , Yao Wang , Dayong An , Xuchen Zhang , Shuyuan Zhang , Senmao Liang , Hao Xiang , Chao Yang , Weijia Gong

The local stress field in α-Zr matrix induced by δ-hydride precipitation is known to affect hydride microstructure, whereas the underlying mechanism remains ambiguous. This study exploits phase-field modeling of six δ-variants corresponding to potential shearing directions for the α-δ transformation to investigate influences of precipitation stresses on the nucleation and interaction behaviors of hydride platelets, in association with high angular-resolution electron backscatter diffraction (HR-EBSD) determination. Both the modeling and experimental results demonstrate that the precipitation stresses are characterized as significant concentration of triaxial tension and the

{0001}_{α} {< 10 - 10 >}_{α}

shear component in the vicinity of hydride tips. This characteristic of stress distribution is further identified to promote autocatalytic nucleation and variant selection of daughter hydrides at tips of a pre-existing one. With respect to the pre-existing variant, the identical type and the opposite shearing variant exhibiting prevailing formation probabilities beyond the others, yet distinct nucleation sites due to stress gradient of the shear component. Hydride evolution simulations reveal that the identical variants stack into chain structures characterized by intermediate gaps yielding compressive stress, while the variants with opposite shear directions form intersections where the shear stress is effectively relieved. This work elucidates the governing influence of precipitation stresses on the autocatalytic nucleation and stacking interaction of hydrides, providing new insights into hydride formation mechanism in zirconium alloys.

α-Zr基体中δ-氢化物析出引起的局部应力场影响了氢化物的微观结构，但其作用机制尚不清楚。本研究利用α-δ转变潜在剪切方向对应的6个δ-变量相场模型，结合高角分辨电子背散射衍射（HR-EBSD）测定，研究了沉淀应力对氢化物薄片成核和相互作用行为的影响。模型和实验结果均表明，在氢化物顶端附近，析出应力表现为显著的三轴拉伸和{0001}α < 101¯0 > α{0001}α < 101¯0 > α剪切分量。这一应力分布特征被进一步鉴定为促进已存在氢化物尖端的子氢化物的自催化成核和变异选择。相对于先前存在的变体，相同类型和相反类型的剪切变体表现出比其他变体更占优势的形成概率，但由于剪切分量的应力梯度，不同的成核位置。氢化物演化模拟表明，相同的氢化物变体叠加成链状结构，其特征是中间间隙产生压应力，而剪切方向相反的氢化物变体形成交集，有效地消除了剪应力。这项工作阐明了沉淀应力对氢化物自催化成核和堆积相互作用的控制作用，为锆合金中氢化物的形成机制提供了新的见解。

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引用次数: 0

Interstitial nitrogen-engineered square-planar Ni surfaces enabling efficient hydrogenation 间隙氮工程的方形平面Ni表面实现高效氢化

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-22 DOI: 10.1016/j.actamat.2026.121954

Yinghui Pu , Yiming Niu , Tongtong Gao , Junnan Chen , Bingsen Zhang

Atomically precise engineering of nanocatalyst surfaces is critical for advancing heterogeneous catalysis, yet achieving both structural uniformity and electronic tunability remains challenging. Here, we report an interstitial atom-mediated strategy for constructing anti-perovskite Ni₃CuN nanocatalysts featuring square-planar Ni surfaces coordinated by nitrogen. The resulting nanoparticles adopt cubic morphologies, undergoing nitrogen-driven facet reconstruction from high-index {210}/{110} planes to thermodynamically favored {100} facets. Atomic-resolution imaging and simulations reveal that these surfaces preferentially expose Ni-N arrangements on (

\bar{1}

00) terminations, in contrast to Ni-Cu configurations on (100) facets. This well-defined surface architecture, characterized by expanded Ni-Ni distances and electron-deficient Ni sites, leads to a substantial enhancement in acetylene hydrogenation selectivity (from 25.5% to 80.1%), while maintaining or surpassing the intrinsic activity of pure Ni and exhibiting excellent stability over 110 h of testing. These findings establish an interstitial atom-based strategy for tailoring catalytic nanostructures with precise control over surface geometry and electronic structure.

纳米催化剂表面的原子精确工程对于推进多相催化至关重要，但实现结构均匀性和电子可调性仍然具有挑战性。在这里，我们报道了一种间隙原子介导的策略，用于构建具有方形平面Ni表面和氮配位的反钙钛矿Ni3CuN纳米催化剂。所得纳米颗粒采用立方形态，经过氮驱动的面重构，从高折射率{210}/{110}平面到热力学有利的{100}面。原子分辨率成像和模拟显示，与（100）面上的Ni-Cu配置相比，这些表面优先暴露（1¯00）端部的Ni-N排列。这种明确的表面结构，以扩大Ni-Ni距离和缺乏电子的Ni位点为特征，导致乙炔加氢选择性大幅提高（从25.5%提高到80.1%），同时保持或超过纯Ni的固有活性，并在110小时的测试中表现出优异的稳定性。这些发现建立了一种基于间隙原子的策略，可以通过精确控制表面几何形状和电子结构来定制催化纳米结构。

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引用次数: 0

Ice crystals under terrestrial and microgravity conditions: Experiments versus theory for tip velocity and tip radius 陆地和微重力条件下的冰晶：尖端速度和尖端半径的实验与理论

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-01-24 DOI: 10.1016/j.actamat.2026.121959

Dmitri V. Alexandrov , Irina E. Koroznikova , Alexandra E. Glebova , Liubov V. Toropova

Based on a number of experiments carried out in microgravity and terrestrial conditions, we demonstrate that the shape of ice dendrite tips sufficiently differs from an elliptical paraboloid. To describe the stable growth mode of such crystals, we apply Geometrically Morphological Theory (Acta Mater. 296 (2025), 121232), Boundary Integral Method (Physica A 469 (2017), 420) and Selection Criterion (Phys. Rep. 1085 (2024) 1). This enables us to theoretically obtain the dendrite tip velocity

V

and tip radius

R_{1}

in the basal plane during the same experiment as the functions of liquid undercooling. Analyzing all available experimental data on the measurements of

V

and

R_{1}

, we determined the integration limit in the heat balance equation and showed that it is close to

0.2 R_{1}

for the tips of ice crystals grown in undercooled normal and heavy water. We show that our approach corresponds to the solvability theory within the scatter of the experimental data for the selection criterion in the basal plane. In general, the developed approach describes all the experimental data in microgravity and on the ground known to us on the growth of ice crystals, where simultaneous measurements of

V

and

R_{1}

were performed.

基于在微重力和地面条件下进行的大量实验，我们证明了冰枝晶尖端的形状与椭圆抛物面有很大的不同。为了描述这种晶体的稳定生长模式，我们应用了几何形态理论（物质学报296(2025),121232），边界积分法（物理学报A 469(2017), 420）和选择准则（物理学报A 469(2017), 420）。众议员1085(2024)1)。这使得我们可以在与液体过冷函数相同的实验中，理论上得到基面上枝晶尖端速度VV和尖端半径R1R1。分析了所有可用的VV和R1R1测量的实验数据，确定了热平衡方程中的积分极限，并表明在过冷的正常水和重水中生长的冰晶尖端接近0.2 r10.21 r1。我们证明了我们的方法在基面上的选择准则的实验数据的散射范围内符合可解性理论。总的来说，开发的方法描述了我们在微重力和地面上已知的冰晶生长的所有实验数据，同时测量了VV和R1R1。

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引用次数: 0

Tunable photocatalytic properties via layer-controlled polarization in 2D SnP2Se6/GaN heterostructures 基于层控极化的二维SnP2Se6/GaN异质结构的可调光催化性能

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-04-01 Epub Date: 2026-02-02 DOI: 10.1016/j.actamat.2026.121979

Minglei Jia , Mengyue Lan , Tiexin Zhu , Zhaoyang Han , Chao Jin , Bing Wang

The polarization field within the heterostructure (HS) significantly affects the photocatalytic properties, especially in the separation and migration of photo-generated charge carriers. Controlling the polarization field can optimize the efficiency, selectivity, and rate of catalytic reactions, making it a key factor in designing efficient photocatalysts. This work systematically investigates the construction of SnP₂Se₆/GaN HSs with varying GaN layer thicknesses, aiming to modulate their electronic structures and photocatalytic properties. The computational results reveal that all the HSs exhibit a typical Type-II band alignment, which effectively facilitates the separation and transfer of photo-generated charge carriers, thereby significantly enhancing photocatalytic performance. In particular, when the number of GaN layers is even, a notable polarization field is induced across the HSs, resulting in a potential difference between the two sides and a corresponding shift in the band-edge positions. Further detailed investigations into the photocatalytic water splitting reaction kinetics indicate that the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance of the HSs are substantially improved compared to the individual GaN and SnP₂Se₆ components. Furthermore, by controlling the GaN layer number, the rate and selectivity of the water splitting process can be fine-tuned. This work offers novel insights and presents a promising strategy for the design of multifunctional photocatalytic materials.

异质结构（HS）内的极化场显著影响光催化性能，特别是光生载流子的分离和迁移。控制极化场可以优化催化反应的效率、选择性和速率，是设计高效光催化剂的关键因素。本研究系统地研究了具有不同GaN层厚度的SnP2Se6/GaN hs的构建，旨在调节其电子结构和光催化性能。计算结果表明，所有hs都呈现出典型的ii型带排列，这有效地促进了光生载流子的分离和转移，从而显著提高了光催化性能。特别是，当GaN层数相等时，在HSs上产生明显的极化场，导致两侧电位差和带边位置的相应移位。对光催化水裂解反应动力学的进一步详细研究表明，与单个GaN和SnP2Se6组分相比，HSs的析氢反应（HER）和析氧反应（OER）性能有显著提高。此外，通过控制氮化镓层数，可以微调水分解过程的速率和选择性。这项工作为多功能光催化材料的设计提供了新的见解和有前途的策略。

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