Hexagonal noncollinear antiferromagnets, such as Mn3Sn, Mn3Ge, and Mn3Ga, have garnered significant attention in recent years due to their potential for supplying large anisotropic anomalous and spin Hall conductance. In particular, noncollinear antiferromagnetic tunnel junctions have been fabricated, demonstrating their applications in antiferromagnetic spintronics in future. However, hexagonal Mn3Al, a noncollinear antiferromagnet that has non-heavy metal elements, has never been reported. In this study, we not only predict the noncollinear antiferromagnet Mn3Al through first-principles calculations and experimentally confirm the existence of hexagonal Mn3Al, but also predict the existence of large anomalous Hall conductance for Mn3Al. Our calculations reveal that Mn3Al can be utilized in antiferromagnetic tunnel junctions and possesses anisotropic anomalous Hall conductance. Our calculations show a large = 1398 above the Fermi level, which is caused by the Weyl points in momentum space for Mn3Al. could be raised from 99.7 for Mn3Al to 412 for Mn3Al0.5Si0.5 at Fermi level by substituting the Al atoms with Si atoms. More Si content further raises the value of to a maximum 952 for Mn3Al0.35Si0.65 within the rigid band approximation. Furthermore, the films grown on Si(111) substrates suggest compatibility with semiconductor devices, thus broadening the applications of Mn3Al and expanding the family of noncollinear antiferromagnets.
{"title":"New noncollinear antiferromagnet Mn3Al for antiferromagnetic spintronics","authors":"Bing Lv, Mingsu Si, Long Cheng, Zhongjie Yan, Xiaolin Li, Cunxu Gao","doi":"10.1016/j.actamat.2025.120939","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120939","url":null,"abstract":"Hexagonal noncollinear antiferromagnets, such as Mn<sub>3</sub>Sn, Mn<sub>3</sub>Ge, and Mn<sub>3</sub>Ga, have garnered significant attention in recent years due to their potential for supplying large anisotropic anomalous and spin Hall conductance. In particular, noncollinear antiferromagnetic tunnel junctions have been fabricated, demonstrating their applications in antiferromagnetic spintronics in future. However, hexagonal Mn<sub>3</sub>Al, a noncollinear antiferromagnet that has non-heavy metal elements, has never been reported. In this study, we not only predict the noncollinear antiferromagnet Mn<sub>3</sub>Al through first-principles calculations and experimentally confirm the existence of hexagonal Mn<sub>3</sub>Al, but also predict the existence of large anomalous Hall conductance for Mn<sub>3</sub>Al. Our calculations reveal that Mn<sub>3</sub>Al can be utilized in antiferromagnetic tunnel junctions and possesses anisotropic anomalous Hall conductance. Our calculations show a large <span><math><msub is=\"true\"><mrow is=\"true\"><mi is=\"true\">σ</mi></mrow><mrow is=\"true\"><mi is=\"true\">z</mi><mi is=\"true\">x</mi></mrow></msub></math></span> = 1398 <span><math><msup is=\"true\"><mrow is=\"true\"><mi is=\"true\" mathvariant=\"normal\">(Ω⋅cm)</mi></mrow><mrow is=\"true\"><mo is=\"true\">−</mo><mn is=\"true\">1</mn></mrow></msup></math></span> above the Fermi level, which is caused by the Weyl points in momentum space for Mn<sub>3</sub>Al. <span><math><msub is=\"true\"><mrow is=\"true\"><mi is=\"true\">σ</mi></mrow><mrow is=\"true\"><mi is=\"true\">z</mi><mi is=\"true\">x</mi></mrow></msub></math></span> could be raised from 99.7 <span><math><msup is=\"true\"><mrow is=\"true\"><mi is=\"true\" mathvariant=\"normal\">(Ω⋅cm)</mi></mrow><mrow is=\"true\"><mo is=\"true\">−</mo><mn is=\"true\">1</mn></mrow></msup></math></span> for Mn<sub>3</sub>Al to 412 <span><math><msup is=\"true\"><mrow is=\"true\"><mi is=\"true\" mathvariant=\"normal\">(Ω⋅cm)</mi></mrow><mrow is=\"true\"><mo is=\"true\">−</mo><mn is=\"true\">1</mn></mrow></msup></math></span> for Mn<sub>3</sub>Al<sub>0.5</sub>Si<sub>0.5</sub> at Fermi level by substituting the Al atoms with Si atoms. More Si content further raises the value of <span><math><msub is=\"true\"><mrow is=\"true\"><mi is=\"true\">σ</mi></mrow><mrow is=\"true\"><mi is=\"true\">z</mi><mi is=\"true\">x</mi></mrow></msub></math></span> to a maximum 952 <span><math><msup is=\"true\"><mrow is=\"true\"><mi is=\"true\" mathvariant=\"normal\">(Ω⋅cm)</mi></mrow><mrow is=\"true\"><mo is=\"true\">−</mo><mn is=\"true\">1</mn></mrow></msup></math></span> for Mn<sub>3</sub>Al<sub>0.35</sub>Si<sub>0.65</sub> within the rigid band approximation. Furthermore, the films grown on Si(111) substrates suggest compatibility with semiconductor devices, thus broadening the applications of Mn<sub>3</sub>Al and expanding the family of noncollinear antiferromagnets.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"215 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-23DOI: 10.1016/j.actamat.2025.120969
Jiaying Jin, Wang Chen, Yongming Tao, Hansheng Chen, Liang Zhou, Xinhua Wang, Chen Wu, Simon P. Ringer, Mi Yan
Control of the REFe2 (RE = rare earth) intergranular phase is of vital importance for developing Ce-rich Nd–Ce–Fe–B magnets that can rival the performance of conventional Nd–Fe–B magnets. Here we systematically investigate the evolution of the REFe2 phase in a multi-main-phase Ce12.8(Pr, Nd)19.2Fe65.33MbalB0.9 magnet (Ce/total RE = 40 wt.%) triggered by wide-range post-sinter annealing (300–950 °C). Following a scan of the temperature dependence of coercivity, two annealing temperatures of 420 °C and 650 °C yield higher coercivity, but via different mechanisms. 420 °C annealing facilitates the formation of the REFe2 phase, and partially thickened grain boundary (GB). 650 °C annealing results in the decomposition of the REFe2 phase, and its re-formation during furnace cooling. In fact, comparing cooling from 650 °C via water-quenching, air-cooling and furnace-cooling demonstrates that the latter (slowest) cooling rate yields the maximum REFe2 phase fraction of 5.4 wt.%. Significantly, the formation of this REFe2 phase is accompanied by the expulsion of Ce from RE2Fe14B matrix shell, and the concomitant infiltration of Nd into RE2Fe14B matrix shell. As a result, a maximum compositional difference between Nd and Ce in the matrix shell is recorded in the 650 °C furnace-cooled sample ([Nd]shell – [Ce]shell = 7.1 wt.%), yielding a maximum coercivity of 12.6 kOe. This work unveils the temperature-dependent evolution of the REFe2 phase in Nd–Ce–Fe–B sintered magnets, and the nature and kinetics of the Ce and Nd redistribution.
{"title":"Temperature-dependent evolution of REFe2 phase and correlated coercivity responses in post-sinter annealed Nd–Ce–Fe–B magnets","authors":"Jiaying Jin, Wang Chen, Yongming Tao, Hansheng Chen, Liang Zhou, Xinhua Wang, Chen Wu, Simon P. Ringer, Mi Yan","doi":"10.1016/j.actamat.2025.120969","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120969","url":null,"abstract":"Control of the REFe<sub>2</sub> (RE = rare earth) intergranular phase is of vital importance for developing Ce-rich Nd–Ce–Fe–B magnets that can rival the performance of conventional Nd–Fe–B magnets. Here we systematically investigate the evolution of the REFe<sub>2</sub> phase in a multi-main-phase Ce<sub>12.8</sub>(Pr, Nd)<sub>19.2</sub>Fe<sub>65.33</sub>M<sub>bal</sub>B<sub>0.9</sub> magnet (Ce/total RE = 40 wt.%) triggered by wide-range post-sinter annealing (300–950 °C). Following a scan of the temperature dependence of coercivity, two annealing temperatures of 420 °C and 650 °C yield higher coercivity, but via different mechanisms. 420 °C annealing facilitates the formation of the REFe<sub>2</sub> phase, and partially thickened grain boundary (GB). 650 °C annealing results in the decomposition of the REFe<sub>2</sub> phase, and its re-formation during furnace cooling. In fact, comparing cooling from 650 °C via water-quenching, air-cooling and furnace-cooling demonstrates that the latter (slowest) cooling rate yields the maximum REFe<sub>2</sub> phase fraction of 5.4 wt.%. Significantly, the formation of this REFe<sub>2</sub> phase is accompanied by the expulsion of Ce from RE<sub>2</sub>Fe<sub>14</sub>B matrix shell, and the concomitant infiltration of Nd into RE<sub>2</sub>Fe<sub>14</sub>B matrix shell. As a result, a maximum compositional difference between Nd and Ce in the matrix shell is recorded in the 650 °C furnace-cooled sample ([Nd]<sub>shell</sub> – [Ce]<sub>shell</sub> = 7.1 wt.%), yielding a maximum coercivity of 12.6 kOe. This work unveils the temperature-dependent evolution of the REFe<sub>2</sub> phase in Nd–Ce–Fe–B sintered magnets, and the nature and kinetics of the Ce and Nd redistribution.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"71 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.actamat.2025.120963
Xing Gong, Li Wan, Mingxin Gao, Thierry Auger, Kaiyun Chen, Pei Wang, Michael P. Short, Jing Liu, Jian Luo
In this paper, the dissolution corrosion mechanism of 316L steels fabricated by laser-powder-bed-fusion (LPBF) with and without subsequent hot-isostatic-pressing (HIP) has been studied under multilength scales after exposure to static lead-bismuth eutectic (LBE) with a reactor-relevant oxygen concentration of ∼5×10−7wt.% dissolved, at 500°C for up to 4000h. The results show that both steels are subjected to dissolution corrosion with LBE preferentially attacking defective areas. The average dissolution depths of “LPBF 316L” steel are much larger than those of “LPBF+HIP 316L” steel, suggesting that the nonequilibrium defects generated by LPBF significantly exacerbate dissolution corrosion, whereas dissolution resistance recovers following HIP treatment. The dissolution zones invariably undergo austenite-to-ferrite phase transformation. Kurdjumov-Sachs (K-S) and Nishiyama-Wassermann (N-W) are the predominant orientation relationships (ORs) of α and γ phases, especially in “LPBF+HIP 316L” steel. While Pitsch OR is also identified, it constitutes only a small fraction. Atomic-resolution characterization reveals that at the penetration tips along mechanical nanotwin boundaries, a one-nanometer-thick, Bi- and Ni-rich, coherent interfacial phase forms at the interface between steel matrix and a nanosized amorphous oxide scale, mediating the leaching of Ni. Theoretical computations confirm that Bi is energetically more favorable than Pb in segregating on austenitic steel surfaces. The interfacial segregation of Bi facilitates the outer diffusion of Ni due to the negative enthalpy of mixing of the Ni-Bi system. Fe and Cr are also extracted through oxidation/decomposition processes. Consequently, the dissolution process involves simultaneous removal of all three steel elements, rather than just Ni. An atomic-scale dissolution mechanism scheme is proposed.
{"title":"Atomic-scale dissolution corrosion mechanism of additively-manufactured 316L steels in liquid lead-bismuth eutectic","authors":"Xing Gong, Li Wan, Mingxin Gao, Thierry Auger, Kaiyun Chen, Pei Wang, Michael P. Short, Jing Liu, Jian Luo","doi":"10.1016/j.actamat.2025.120963","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120963","url":null,"abstract":"In this paper, the dissolution corrosion mechanism of 316L steels fabricated by laser-powder-bed-fusion (LPBF) with and without subsequent hot-isostatic-pressing (HIP) has been studied under multilength scales after exposure to static lead-bismuth eutectic (LBE) with a reactor-relevant oxygen concentration of ∼5×10<sup>−7</sup>wt.% dissolved, at 500°C for up to 4000h. The results show that both steels are subjected to dissolution corrosion with LBE preferentially attacking defective areas. The average dissolution depths of “LPBF 316L” steel are much larger than those of “LPBF+HIP 316L” steel, suggesting that the nonequilibrium defects generated by LPBF significantly exacerbate dissolution corrosion, whereas dissolution resistance recovers following HIP treatment. The dissolution zones invariably undergo austenite-to-ferrite phase transformation. Kurdjumov-Sachs (K-S) and Nishiyama-Wassermann (N-W) are the predominant orientation relationships (ORs) of <em>α</em> and <em>γ</em> phases, especially in “LPBF+HIP 316L” steel. While Pitsch OR is also identified, it constitutes only a small fraction. Atomic-resolution characterization reveals that at the penetration tips along mechanical nanotwin boundaries, a one-nanometer-thick, Bi- and Ni-rich, coherent interfacial phase forms at the interface between steel matrix and a nanosized amorphous oxide scale, mediating the leaching of Ni. Theoretical computations confirm that Bi is energetically more favorable than Pb in segregating on austenitic steel surfaces. The interfacial segregation of Bi facilitates the outer diffusion of Ni due to the negative enthalpy of mixing of the Ni-Bi system. Fe and Cr are also extracted through oxidation/decomposition processes. Consequently, the dissolution process involves simultaneous removal of all three steel elements, rather than just Ni. An atomic-scale dissolution mechanism scheme is proposed.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"34 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.actamat.2025.120965
Xiaotian Fang, Valeria Viteri-Pflucker, Alexander H. King, Jian Wang, Jiaqiang Yan, Liqin Ke, Lin Zhou
Grain boundary migration is usually considered to occur through the consistent motion of grain boundaries toward their centers of curvature, ultimately leading to grain growth. However, we show that in 2D skyrmion polycrystals comprising individual grains of hexagonal symmetry, grain boundaries can undergo large amplitude oscillations while maintaining their basic geometric features. Wave-like boundary motion, triggered by individual and collective motion of particles at the grain boundaries, is a behavior that is not accounted for in traditional models of grain boundary migration. Our findings highlight the need for further investigation into the dynamics of grain boundaries during grain growth.
{"title":"Oscillating Grain Boundaries and Their Effects on Grain Growth: Observations in Skyrmion Bicrystals","authors":"Xiaotian Fang, Valeria Viteri-Pflucker, Alexander H. King, Jian Wang, Jiaqiang Yan, Liqin Ke, Lin Zhou","doi":"10.1016/j.actamat.2025.120965","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120965","url":null,"abstract":"Grain boundary migration is usually considered to occur through the consistent motion of grain boundaries toward their centers of curvature, ultimately leading to grain growth. However, we show that in 2D skyrmion polycrystals comprising individual grains of hexagonal symmetry, grain boundaries can undergo large amplitude oscillations while maintaining their basic geometric features. Wave-like boundary motion, triggered by individual and collective motion of particles at the grain boundaries, is a behavior that is not accounted for in traditional models of grain boundary migration. Our findings highlight the need for further investigation into the dynamics of grain boundaries during grain growth.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"61 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.actamat.2025.120860
Sepideh Kavousi, Mohsen Asle Zaeem
This study presents an integration of machine learning (ML) with a multiscale computational framework to predict primary dendrite arm spacing (PDAS) during alloy solidification. Analytical models, such as Hunt (HT) and Kurz-Fisher (KF), provide the basis for developing parametric and non-parametric ML models that capture the influence of processing conditions and material properties on PDAS. The training and testing dataset is generated from high-throughput phase-field simulations across various alloy systems, incorporating material properties calculated via molecular dynamics. While non-parametric models, such as decision trees, random forests, and gradient boosting decision trees, perform well in training, they encounter overfitting challenges due to the limited size of the computational dataset. In contrast, parametric models, including linear, ridge, and lasso regression, successfully capture key PDAS features, producing predictions that align closely with experimental data. Overall, parametric ML-based models show a stronger dependence on pulling velocity, temperature gradient, and material properties compared to the HT and KF models, offering a more accurate tool for predicting PDAS and optimizing alloy solidification processes.
{"title":"Integration of multiscale simulations and machine learning for predicting dendritic microstructures in solidification of alloys","authors":"Sepideh Kavousi, Mohsen Asle Zaeem","doi":"10.1016/j.actamat.2025.120860","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120860","url":null,"abstract":"This study presents an integration of machine learning (ML) with a multiscale computational framework to predict primary dendrite arm spacing (PDAS) during alloy solidification. Analytical models, such as Hunt (HT) and Kurz-Fisher (KF), provide the basis for developing parametric and non-parametric ML models that capture the influence of processing conditions and material properties on PDAS. The training and testing dataset is generated from high-throughput phase-field simulations across various alloy systems, incorporating material properties calculated via molecular dynamics. While non-parametric models, such as decision trees, random forests, and gradient boosting decision trees, perform well in training, they encounter overfitting challenges due to the limited size of the computational dataset. In contrast, parametric models, including linear, ridge, and lasso regression, successfully capture key PDAS features, producing predictions that align closely with experimental data. Overall, parametric ML-based models show a stronger dependence on pulling velocity, temperature gradient, and material properties compared to the HT and KF models, offering a more accurate tool for predicting PDAS and optimizing alloy solidification processes.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"183 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.actamat.2025.120964
Su Yan, Linfeng Zhang, Weimo Li, Ruikai Qi, Mengxiao Zhong, Meijiao Xu, Wei Song, Xiaofeng Lu
Anodic oxygen evolution reaction (OER) is crucial for several clean energy storage and conversion processes, like the rechargeable Zn-air battery and electrocatalytic water splitting. However, constructing advanced OER electrocatalysts with exceptional higher activity and stability compared to commercial IrO2 and RuO2 remains a significant challenge. Herein, a high-entropy alloy material consisting of five metal elements (Co, Ni, Ru, Ir, and Mn) with a 3D porous network structure is reported to be fabricated through a facile and mild one-pot co-reduction method, enabling its excellent electron/mass transport property and the modulated d-band center to optimize the intermediates adsorption in electrocatalysis. Therefore, the resultant CoNiRuIrMn sample exhibits the overpotentials of merely 169 mV to deliver 10 mA cm−2 in alkaline environment, greatly lower than that of the commercial electrocatalysts (RuO2 and IrO2). Significantly, the CoNiRuIrMn catalyst demonstrates an ultrahigh mass activity of 376.2 A g−1, which is 110.6- and 63.8-fold greater than those of IrO2 and RuO2 catalysts, respectively. Furthermore, the overall water splitting device assembled with CoNiRuIrMn and Pt/C catalyst presents a much better operation voltage and long-term stability than RuO2||Pt/C and IrO2||Pt/C electrolyzers, showcasing its promising potential for efficient hydrogen production.
{"title":"Constructing CoNiRuIrMn High-entropy Alloy Network for Boosting Electrocatalytic Activity toward Alkaline Water Oxidation","authors":"Su Yan, Linfeng Zhang, Weimo Li, Ruikai Qi, Mengxiao Zhong, Meijiao Xu, Wei Song, Xiaofeng Lu","doi":"10.1016/j.actamat.2025.120964","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120964","url":null,"abstract":"Anodic oxygen evolution reaction (OER) is crucial for several clean energy storage and conversion processes, like the rechargeable Zn-air battery and electrocatalytic water splitting. However, constructing advanced OER electrocatalysts with exceptional higher activity and stability compared to commercial IrO<sub>2</sub> and RuO<sub>2</sub> remains a significant challenge. Herein, a high-entropy alloy material consisting of five metal elements (Co, Ni, Ru, Ir, and Mn) with a 3D porous network structure is reported to be fabricated through a facile and mild one-pot co-reduction method, enabling its excellent electron/mass transport property and the modulated <em>d</em>-band center to optimize the intermediates adsorption in electrocatalysis. Therefore, the resultant CoNiRuIrMn sample exhibits the overpotentials of merely 169 mV to deliver 10 mA cm<sup>−2</sup> in alkaline environment, greatly lower than that of the commercial electrocatalysts (RuO<sub>2</sub> and IrO<sub>2</sub>). Significantly, the CoNiRuIrMn catalyst demonstrates an ultrahigh mass activity of 376.2 A g<sup>−1</sup>, which is 110.6- and 63.8-fold greater than those of IrO<sub>2</sub> and RuO<sub>2</sub> catalysts, respectively. Furthermore, the overall water splitting device assembled with CoNiRuIrMn and Pt/C catalyst presents a much better operation voltage and long-term stability than RuO<sub>2</sub>||Pt/C and IrO<sub>2</sub>||Pt/C electrolyzers, showcasing its promising potential for efficient hydrogen production.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"57 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.actamat.2025.120937
Yang Li, Raj K. Koju, Yuri Mishin
Molecular dynamics and parallel-replica dynamics simulations are applied to investigate the atomic structures and diffusion processes at Al{111}∥Si{111} interphase boundaries constructed by simulated vapor deposition of Al(Si) alloy on Si(111) substrates. Different orientation relationships and interface structures are obtained for different pre-deposition Si (111) surface reconstructions. Diffusion of both Al and Si atoms at the interfaces is calculated and compared with diffusion along grain boundaries, triple junctions, contact lines, and threading dislocations in the Al–Si system. It is found that Al{111}∥Si{111} interphase boundaries exhibit the lowest diffusivity among these structures and are closest to the lattice diffusivity. In most cases (except for the Si substrate), Si atoms are more mobile than Al atoms. The diffusion processes are typically mediated by Al vacancies and Si interstitial atoms migrating by either direct or indirect interstitial mechanisms.
{"title":"Atomistic investigation of diffusion processes at Al(Si)/Si(111) interphase boundaries obtained by simulated vapor deposition","authors":"Yang Li, Raj K. Koju, Yuri Mishin","doi":"10.1016/j.actamat.2025.120937","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120937","url":null,"abstract":"Molecular dynamics and parallel-replica dynamics simulations are applied to investigate the atomic structures and diffusion processes at <mml:math altimg=\"si1.svg\" display=\"inline\"><mml:mrow><mml:mtext>Al</mml:mtext><mml:mrow><mml:mo>{</mml:mo><mml:mn>111</mml:mn><mml:mo>}</mml:mo></mml:mrow><mml:mo linebreak=\"goodbreak\" linebreakstyle=\"after\">∥</mml:mo><mml:mtext>Si</mml:mtext><mml:mrow><mml:mo>{</mml:mo><mml:mn>111</mml:mn><mml:mo>}</mml:mo></mml:mrow></mml:mrow></mml:math> interphase boundaries constructed by simulated vapor deposition of Al(Si) alloy on Si(111) substrates. Different orientation relationships and interface structures are obtained for different pre-deposition Si (111) surface reconstructions. Diffusion of both Al and Si atoms at the interfaces is calculated and compared with diffusion along grain boundaries, triple junctions, contact lines, and threading dislocations in the Al–Si system. It is found that <mml:math altimg=\"si1.svg\" display=\"inline\"><mml:mrow><mml:mtext>Al</mml:mtext><mml:mrow><mml:mo>{</mml:mo><mml:mn>111</mml:mn><mml:mo>}</mml:mo></mml:mrow><mml:mo linebreak=\"goodbreak\" linebreakstyle=\"after\">∥</mml:mo><mml:mtext>Si</mml:mtext><mml:mrow><mml:mo>{</mml:mo><mml:mn>111</mml:mn><mml:mo>}</mml:mo></mml:mrow></mml:mrow></mml:math> interphase boundaries exhibit the lowest diffusivity among these structures and are closest to the lattice diffusivity. In most cases (except for the Si substrate), Si atoms are more mobile than Al atoms. The diffusion processes are typically mediated by Al vacancies and Si interstitial atoms migrating by either direct or indirect interstitial mechanisms.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"21 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-21DOI: 10.1016/j.actamat.2025.120962
Changtai Li, Xu Han, Chao Yao, Yu Guo, Zixin Li, Lei Jiang, Wei Liu, Haiyou Huang, Huadong Fu, Xiaojuan Ban
The precise quantitative description of material microstructures is essential for deeply exploring the relationship between material composition and property. This significant understanding efficiently enables composition design, process optimization, and property enhancement. Traditionally, the analysis of material microstructures has relied heavily on professional expertise. Even with machine /deep learning (ML/DL)-based analysis methods, substantial expert annotation is required for training, and the trained models often suffer from weak generalizability and poor recognition of new images. This study proposed MatSAM (Materials Segment Anything Model), a novel training-free approach for efficient material microstructure extraction based on the Segment Anything Model (SAM), a type of visual large model (VLM). Integrating region marking and microscopy-adapted points, an automated point-based prompt strategy was developed to achieve accurate and efficient material microstructure recognition. Without any manual annotations, MatSAM precisely identified 11 kinds of metallic material microstructures obtained through various characterization methods. Compared to optimal conventional rule-based methods that do not involve a learning process (non-ML/DL), MatSAM achieved an average relative improvement of 35.4% in metrics combining the adjusted Rand index (ARI) and Intersection over Union (IoU), outperforming the original SAM by an average of 13.9%. On four public microstructure segmentation datasets, the IoU of MatSAM showed an average improvement of 7.5% over corresponding specialist deep models requiring annotations. Meanwhile, MatSAM satisfied the generalization capability of a single model for various microstructures, including grain boundaries, phases, and defects. This approach significantly reduces the labor and computational costs of quantitatively characterizing material microstructures, further accelerating the development of advanced materials.
{"title":"A novel training-free approach to efficiently extracting material microstructures via visual large model","authors":"Changtai Li, Xu Han, Chao Yao, Yu Guo, Zixin Li, Lei Jiang, Wei Liu, Haiyou Huang, Huadong Fu, Xiaojuan Ban","doi":"10.1016/j.actamat.2025.120962","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120962","url":null,"abstract":"The precise quantitative description of material microstructures is essential for deeply exploring the relationship between material composition and property. This significant understanding efficiently enables composition design, process optimization, and property enhancement. Traditionally, the analysis of material microstructures has relied heavily on professional expertise. Even with machine /deep learning (ML/DL)-based analysis methods, substantial expert annotation is required for training, and the trained models often suffer from weak generalizability and poor recognition of new images. This study proposed MatSAM (Materials Segment Anything Model), a novel training-free approach for efficient material microstructure extraction based on the Segment Anything Model (SAM), a type of visual large model (VLM). Integrating region marking and microscopy-adapted points, an automated point-based prompt strategy was developed to achieve accurate and efficient material microstructure recognition. Without any manual annotations, MatSAM precisely identified 11 kinds of metallic material microstructures obtained through various characterization methods. Compared to optimal conventional rule-based methods that do not involve a learning process (non-ML/DL), MatSAM achieved an average relative improvement of 35.4% in metrics combining the adjusted Rand index (ARI) and Intersection over Union (IoU), outperforming the original SAM by an average of 13.9%. On four public microstructure segmentation datasets, the IoU of MatSAM showed an average improvement of 7.5% over corresponding specialist deep models requiring annotations. Meanwhile, MatSAM satisfied the generalization capability of a single model for various microstructures, including grain boundaries, phases, and defects. This approach significantly reduces the labor and computational costs of quantitatively characterizing material microstructures, further accelerating the development of advanced materials.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"183 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-21DOI: 10.1016/j.actamat.2025.120946
Tara Nenninger, Frederic Sansoz
Spectral analysis of local atomic environments has become a powerful tool for studying solute atom segregation and interactions at grain boundaries in nanocrystalline alloys. When applied to individual grain boundaries, the spectral analysis has shown that solute-solute interaction can be either attractive or repulsive, with long-range relative attraction enhancing the likelihood for solute atoms to begin clustering. In this article, we combine this analysis with a new grain-boundary structure descriptor based on grain-boundary atom coordination, to investigate the impact of grain-boundary junctions on solute atom segregation in polycrystals. Specifically, we systematically characterize the tendency of solute clusters to begin forming at various types of ordinary grain boundaries, triple junctions, and high-order junctions in Ag polycrystals containing either Ni or Cu solute atoms. Our findings demonstrate that the formation of solute clusters at grain boundaries is primarily driven by long-range relative solute attraction, rather than short-range solute-solute interactions. This effect is most pronounced near grain-boundary junctions. Our study highlights the multiscale nature of solute segregation at crystalline interfaces and provides new insights into the complex phenomena governing heterogeneous solute segregation in grain-boundary networks.
{"title":"Solute Clustering in Polycrystals: Unveiling the Interplay of Grain Boundary Junction and Long-Range Solute Attraction Effects","authors":"Tara Nenninger, Frederic Sansoz","doi":"10.1016/j.actamat.2025.120946","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120946","url":null,"abstract":"Spectral analysis of local atomic environments has become a powerful tool for studying solute atom segregation and interactions at grain boundaries in nanocrystalline alloys. When applied to individual grain boundaries, the spectral analysis has shown that solute-solute interaction can be either attractive or repulsive, with long-range relative attraction enhancing the likelihood for solute atoms to begin clustering. In this article, we combine this analysis with a new grain-boundary structure descriptor based on grain-boundary atom coordination, to investigate the impact of grain-boundary junctions on solute atom segregation in polycrystals. Specifically, we systematically characterize the tendency of solute clusters to begin forming at various types of ordinary grain boundaries, triple junctions, and high-order junctions in Ag polycrystals containing either Ni or Cu solute atoms. Our findings demonstrate that the formation of solute clusters at grain boundaries is primarily driven by long-range relative solute attraction, rather than short-range solute-solute interactions. This effect is most pronounced near grain-boundary junctions. Our study highlights the multiscale nature of solute segregation at crystalline interfaces and provides new insights into the complex phenomena governing heterogeneous solute segregation in grain-boundary networks.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"61 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-20DOI: 10.1016/j.actamat.2025.120958
M. Modak, Rahul Kaiwart, Santosh K. Gupta, Abhilash Dwivedi, K.K. Pandey, A.K. Poswal, H.K. Poswal
In this article, we report on the structural stability of Er2Ti2O7 cubic pyrochlore under pressure, investigated using x-ray diffraction, Raman spectroscopy, photoluminescence, x-ray absorption spectroscopy (XAS), and ab-initio calculations. Our studies reveal a phase transition from the ambient cubic phase to a high-pressure orthorhombic (cotunnite) phase, initiated at around 40 GPa. The transformation is gradual and does not complete even at the highest pressure studied (∼60.0 GPa). This is further corroborated by first-principles calculations, which indicate that the cotunnite phase becomes energetically more stable than the cubic phase above ∼53 GPa. Upon the complete release of pressure, the high-pressure cotunnite phase is retained, while the untransformed pyrochlore phase partially becomes amorphous. Additionally, XAS data from the recovered sample, taken after pressure cycling at the L3 edge of Er³⁺ ions, show an increase in the cation coordination number during the structural transition. EXAFS analysis suggests that the high-pressure phase has an average Erbium coordination number between 9 and 10. The structural transformation mechanism is attributed to the accumulation of cation antisite defects, which cause subsequent disordering of the cations and anions within their respective sublattices. The amorphization of the pyrochlore phase upon pressure release is interpreted as the result of the inability to accommodate the point defects formed during compression at ambient conditions.
{"title":"Higher coordinated Erbium in Er2Ti2O7 under high-pressure","authors":"M. Modak, Rahul Kaiwart, Santosh K. Gupta, Abhilash Dwivedi, K.K. Pandey, A.K. Poswal, H.K. Poswal","doi":"10.1016/j.actamat.2025.120958","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120958","url":null,"abstract":"In this article, we report on the structural stability of Er<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> cubic pyrochlore under pressure, investigated using x-ray diffraction, Raman spectroscopy, photoluminescence, x-ray absorption spectroscopy (XAS), and <em>ab-initio</em> calculations. Our studies reveal a phase transition from the ambient cubic phase to a high-pressure orthorhombic (cotunnite) phase, initiated at around 40 GPa. The transformation is gradual and does not complete even at the highest pressure studied (∼60.0 GPa). This is further corroborated by first-principles calculations, which indicate that the cotunnite phase becomes energetically more stable than the cubic phase above ∼53 GPa. Upon the complete release of pressure, the high-pressure cotunnite phase is retained, while the untransformed pyrochlore phase partially becomes amorphous. Additionally, XAS data from the recovered sample, taken after pressure cycling at the L<sub>3</sub> edge of Er³⁺ ions, show an increase in the cation coordination number during the structural transition. EXAFS analysis suggests that the high-pressure phase has an average Erbium coordination number between 9 and 10. The structural transformation mechanism is attributed to the accumulation of cation antisite defects, which cause subsequent disordering of the cations and anions within their respective sublattices. The amorphization of the pyrochlore phase upon pressure release is interpreted as the result of the inability to accommodate the point defects formed during compression at ambient conditions.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"34 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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