Acta Materialia最新文献

{"title":"Record-breaking electrostrain in NaNbO3-based antiferroelectric ceramics via achieving fully reversible phase transition","authors":"Li Ma ,&nbsp;Zhiyi Che ,&nbsp;Yuanyuan Luo ,&nbsp;Chao Xu ,&nbsp;Zhenyong Cen ,&nbsp;Fujita Toyohisa ,&nbsp;Shujun Zhang ,&nbsp;Jing-Feng Li ,&nbsp;Nengneng Luo","doi":"10.1016/j.actamat.2025.120950","DOIUrl":"10.1016/j.actamat.2025.120950","url":null,"abstract":"<div><div>Antiferroelectric (AFE) materials hold great potential for actuation applications requiring high electrostrains, because of their reversible electric-field-induced AFE and ferroelectric (FE) phase transition. However, pure NaNbO₃ AFE ceramic usually presents a butterfly-shaped strain<em>-</em>electric field (<em>S-E</em>) curve with a small maximum strain (<em>S</em>_m) and a large negative strain (<em>S</em>_neg) under high electric field. Up to date, achieving a fully reversible high <em>S</em>_m in NN-based AFE ceramics has not been successful. Herein, a novel strategy of decreasing electronegativity difference was proposed to modulate the reversible AFE-FE phase transition, by deliberately introducing a dopant with low electronegativity difference, namely, Bi(Mg_1/3Al_1/3Ti_1/3)O₃ into 0.8NaNbO₃–0.2AgNbO₃. Consequently, a record reversible <em>S</em>_m of 0.45 %, free of <em>S</em>_neg, was successfully achieved in 0.75NaNbO₃–0.2AgNbO₃–0.05Bi(Mg_1/3Al_1/3Ti_1/3)O₃ ceramic, about 4.5 times higher than that of pure NaNbO₃ ceramic, together with appropriate frequency and thermal stabilities. Rietveld refinement of XRD demonstrated the decrease of [BO₆] octahedral tilting angles and ionic displacements accounted for the reversible AFE and FE phase transitions. This work provides a promising approach for achieving high electrostain in NaNbO₃-based ceramics, advancing their practical application in electromechanical fields.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120950"},"PeriodicalIF":8.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640203","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}

{"title":"Deformation twinning in a refractory high entropy alloy with B2-ordered crystal structure","authors":"Oleg N. Senkov ,&nbsp;Bryan J. Crossman ,&nbsp;Michael J. Mills","doi":"10.1016/j.actamat.2025.120926","DOIUrl":"10.1016/j.actamat.2025.120926","url":null,"abstract":"<div><div>A B2-ordered Al₁₆Nb₁₀Ta₅Ti₃₃V₅Zr₃₁ refractory high entropy alloy (RHEA) was previously found to exhibit good plasticity in compression from 20 °C to 1000 °C, partially attributed to the extensive deformation twinning occurring within this temperature range. This study observed that deformation twins form almost immediately after yielding, with their density increasing as plastic strain accumulates. Microstructural and crystallographic analyses show that the B2-ordered crystal structure is retained in these twins, which form through the rotation of domains within the parent grain (matrix) about 〈110〉 or 〈112〉 axes to discrete angles that match coincidence-site lattice (CSL) relationships. Conventional shear twin formation is energetically unfavorable in this alloy under the studied conditions because this mechanism requires extensive atomic shuffling to maintain the B2 order. Twins with rotation angles of 10.10°, 13.44°, 14.65°, 16.10°, 17.86°, 20.05°, 22.84°, 26.53°, 31.59°, and 38.94° were identified and analyzed. Twins with larger rotation angles are typically observed at higher plastic strain levels. A rotational twin formation mechanism, consistent with the experimental observations, is proposed and discussed.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"290 ","pages":"Article 120926"},"PeriodicalIF":8.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640206","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}

{"title":"Numerical simulation of birefringence imaging for threading dislocations in 4H-SiC wafers","authors":"Kosei Takahashi ,&nbsp;Yasutaka Matsubara ,&nbsp;Michio Kawase ,&nbsp;Keisuke Seo ,&nbsp;Seiya Mizutani ,&nbsp;Yuya Mizutani ,&nbsp;Seiji Mizutani ,&nbsp;Kenta Murayama ,&nbsp;Shunta Harada","doi":"10.1016/j.actamat.2025.120923","DOIUrl":"10.1016/j.actamat.2025.120923","url":null,"abstract":"<div><div>Silicon carbide (SiC) offers superior physical properties for power device applications. Particularly in its 4H-SiC form, it has outstanding availability of high-quality wafers and further exceptional material characteristics. However, crystalline defects in SiC wafers can degrade their performance. Threading dislocations are the defects of particular interest because of their potential impact on power devices. Birefringence imaging is a promising non-destructive technique that visualizes dislocation-induced stress fields, exploiting the piezooptic effect of the stress fields. Nevertheless, it is difficult to theoretically calculate the birefringence effect of dislocations in crystals because of the complexity of the induced changes in optical properties. This study proposes a numerical simulation model for birefringence imaging of threading dislocations in 4H-SiC wafers to overcome these challenges. In this model, the wafer is discretized into microvolume elements, with light propagation and polarization changes simulated using the composition of Jones matrices. The proposed model accurately reproduces experimental birefringence images, allowing detailed analysis of dislocation characteristics from polarized imaging. Similar considerations can extend this theory to other SiC polytypes than 4H-SiC. This simulation model enables the assessment of dislocation features and improves device performance, productivity, and reliability by addressing the underlying causes of defects.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"290 ","pages":"Article 120923"},"PeriodicalIF":8.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic fracture in gadolinium zirconate single crystal: Micromechanical testing and modelling","authors":"Yang Liu ,&nbsp;Geetha Balakrishnan ,&nbsp;Monica Ciomaga Hatnean ,&nbsp;Ping Xiao ,&nbsp;Ying Chen","doi":"10.1016/j.actamat.2025.120944","DOIUrl":"10.1016/j.actamat.2025.120944","url":null,"abstract":"&lt;div&gt;&lt;div&gt;We report a study on anisotropic fracture in gadolinium zirconate (GZO) using a combination of micromechanical testing and modelling. A GZO single crystal was grown using the floating zone method, and its fracture toughness in 8 different orientations was measured through the microcantilever beam bending tests. The fracture toughness, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, of the GZO single crystal depends on its crystal orientation and follows this ranking order:&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. Fractographic analysis reveals that the crystal planes with low fracture toughness (e.g., &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) exhibit atomically smooth fracture surfaces. In contrast, planes with higher fracture toughness (e.g., &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mover&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) show distinct cleavages and zig-zag crack paths at the atomic scale, with crack deflection toward orientations with lower resistance to cracking. The cleavages and crack deflection increase the fracture surface area, which enables more energy dissipation during the fracture process ","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120944"},"PeriodicalIF":8.3,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breaking through the trade-off between saturation magnetization and coercivity: A data-driven strategy","authors":"Peixin Liu,&nbsp;Hao Lu,&nbsp;Guojing Xu,&nbsp;Feng Cheng,&nbsp;Chongyu Han,&nbsp;Xiaoyan Song","doi":"10.1016/j.actamat.2025.120945","DOIUrl":"10.1016/j.actamat.2025.120945","url":null,"abstract":"<div><div>Remarkable trade-off paradoxes widely exist among different magnetic properties of permanent magnetic alloys, especially between saturation magnetization and coercivity, largely impeding the improvement of comprehensive properties. Taking Sm-Co-based alloys as an example, this study proposed a new data-driven material design strategy to dissolve the saturation magnetization-coercivity trade-off and enhance the comprehensive magnetic properties. The machine learning approach and multi-objective optimization method were applied to establish a model for composition design and microstructure regulation to simultaneously maximize saturation magnetization and coercivity. It was found that the electronegativity of the doping element is a key feature that affects both the saturation magnetization and coercivity, and the Pareto front with appropriate alloy composition and grain size was obtained. The materials with best comprehensive magnetic properties in the optimal set were selected for experimental preparation, and the results fully verified the model predictions. The machine learning model and multi-objective optimization method established in this study break through the trade-off between saturation magnetization and coercivity of Sm-Co-based alloys, and the strategy for synergistic improvement of the mutually exclusive properties is appliable to a variety of multi-objective materials design issues.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120945"},"PeriodicalIF":8.3,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635548","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}

{"title":"Trade-off model for strength-ductility relationship of metallic materials","authors":"X.T. Li ,&nbsp;R. Liu ,&nbsp;J.P. Hou ,&nbsp;Z.J. Zhang ,&nbsp;Z.F. Zhang","doi":"10.1016/j.actamat.2025.120942","DOIUrl":"10.1016/j.actamat.2025.120942","url":null,"abstract":"<div><div>The trade-off relationship between strength and ductility of metallic materials has remained inadequately described by the existing models, resulting in ambiguous strategies for enhancing the strength-ductility synergy. Here, we derive a theoretical trade-off model for the strength-ductility relationship in single-phase metallic materials, which aligns well with the experimental data from various metals and alloys. The trade-off model reveals that the strength-ductility relationship follows a simple inverse proportional function, with variation of grain sizes corresponding to different points on the trade-off strength-ductility curve. Therefore, it is suggested that adjusting grain size alone cannot simultaneously improve both strength and ductility. Intrinsically, the trade-off model identifies three strategies to enhance the strength-ductility synergy: 1) increasing dislocation glide resistance, 2) improving interface strength, and 3) promoting slip uniformity. Further, the correlations between these strategies and material parameters or alloy compositions are discussed, providing significant insights for the optimization and design of metallic materials. Finally, the trade-off model is applied to rapidly establish the quantitative strength-ductility relationship of high-entropy alloys, as well as to classify their mechanical properties into different levels.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120942"},"PeriodicalIF":8.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631429","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}

{"title":"Unifying the atomistic trends for early-stage evolution of TiN surfaces in atmospheric and aqueous environments","authors":"You-Qi Zhou ,&nbsp;Zhangyuan Guo ,&nbsp;Jiachang Bi ,&nbsp;Jin-Tao Ye ,&nbsp;Min Ge ,&nbsp;Yu Lin ,&nbsp;Shaozhu Xiao ,&nbsp;Yanwei Cao ,&nbsp;Liping Wang ,&nbsp;Liang-Feng Huang","doi":"10.1016/j.actamat.2025.120909","DOIUrl":"10.1016/j.actamat.2025.120909","url":null,"abstract":"<div><div>The early-stage evolution of TiN surfaces plays a primary role in determining the reliability of related structural and functional coatings in realistic environments, for which the complex microscopic couplings between TiN and main environmental agents (O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O) still require a unifying portray. By combining density-functional theory with thermodynamic, kinetic, and electrochemical models, we calculate the surface free energies of intrinsic (001), (110), and (111) surfaces, and explore the adsorption and reaction trends of main molecules and radicals on pristine, oxygen-doped, and passivated surfaces, as well as the effects of key environmental parameters (e.g., temperature, atmosphere pressure, solution pH, and electrostatic potential). A relative order of (001) <span><math><mo>&gt;</mo></math></span> (111) <span><math><mo>&gt;</mo></math></span> (110) shows up for the intrinsic stability of TiN surfaces, but an order of (001) <span><math><mo>&lt;</mo></math></span> (110) <span><math><mo>&lt;</mo></math></span> (111) for their resistance against oxidative and corrosive reactions, for which the promoting effect of hydroxyl adsorption is revealed. The electronic-structure and atomistic mechanisms are self-consistently established, and the oxidation and corrosion phenomena of TiN observed in many historical and recent experiments are also unifiedly explained. In addition, the (111) surface is found to be terminated by Ti cations in synthesis, but it is the N-anion layer that renders this surface with inborn resistance against aggressive reactions, making TiN(111) films technologically important. These findings further guide our validatory experiments, where the high-resolution X-ray diffraction and angle-resolved photoelectron spectroscopy are used to characterize the as-synthesized single-crystal TiN(111) films, and the scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy to reveal their corrosion behaviors in strong alkaline and acidic solutions.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120909"},"PeriodicalIF":8.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627739","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}

{"title":"How peritectic melting forms bicontinuous microstructures","authors":"Zhongyang Li ,&nbsp;Lukas Lührs ,&nbsp;Tobias Krekeler ,&nbsp;Jörg Weissmüller","doi":"10.1016/j.actamat.2025.120917","DOIUrl":"10.1016/j.actamat.2025.120917","url":null,"abstract":"<div><div>Fine-scale porous or bicontinuous microstructures may be prepared by liquid-metal dealloying (LMD). Reverse peritectic reactions, and specifically the peritectic melting of TiAg, have been proposed as dealloying-like processes that produce quite similar microstructures but avoid the restrictions on sample size inherent in LMD. Here, studies of the microstructure evolution during peritectic melting of TiAg suggest a formation mechanism that is not LMD-like but rather relies on the migration of liquid films. The process starts with wetting of the TiAg grain boundaries by the alloy melt. Successively, both Ti and Ag continue to dissolve from one side of the wetted boundary, while <span><math><mi>β</mi></math></span>-Ti deposits on the opposite side and the liquid film sweeps the pristine TiAg crystal. TiAg-Ti interfaces with well-defined orientation relationship and with concentration gradients support this picture, as does the phase morphology in partially decomposed samples. The process generates a bicontinuous structure with a solid Ti skeleton, interpenetrated by the Ag-rich melt. The bicontinuity is conserved even after coarsening. Upon quenching, the Ti phase transforms to <span><math><mi>α</mi></math></span>-Ti. This study clarifies the mechanism of peritectic melting in TiAg, and it may provide a basis for identifying other alloy systems suitable for producing bicontinuous microstructures by that process.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120917"},"PeriodicalIF":8.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superior energy-storage performance in BaTiO3-AgNbO3 binary relaxor via the competitions of multiple polar orders","authors":"Minghao Liu ,&nbsp;Hongbo Liu ,&nbsp;Zhen Liu ,&nbsp;Zimeng Hu ,&nbsp;Kai Dai ,&nbsp;Shiguang Yan ,&nbsp;Zhigao Hu ,&nbsp;Genshui Wang","doi":"10.1016/j.actamat.2025.120943","DOIUrl":"10.1016/j.actamat.2025.120943","url":null,"abstract":"<div><div>In the field of dielectric energy storage, ferroelectric ceramics commonly have low electric storage efficiency due to high remanent polarization. Thus, they are usually transformed into relaxors for enhancing electric storage efficiency. In most cases, the transformation not only reduces remanent polarization but also reduces the maximum polarization. To solve the dilemma, we propose a multiple polar orders competing strategy. Experimentally the strategy is achieved in a novel BaTiO₃-AgNbO₃ solid solution. BaTiO₃ is a classic ferroelectric with a long-range polar order while AgNbO₃ is antiferroelectric with multiple antiparallel polar orders. Due to the competitions of multiple polar orders in BaTiO₃-AgNbO₃, during the transformation from ferroelectric to relaxor, the remanent polarization is reduced significantly while the maximum polarization is maintained in the binary solid solution. As a result, a high recoverable energy density (<em>W</em>_rec) of 6.04 J/cm³ with an efficiency (<em>η</em>) of 86.8 % is achieved in the optimized composition of 0.92BaTiO₃–0.08AgNbO₃. Encouragingly, excellent temperature/frequency/fatigue stability and outstanding discharge capability demonstrate its potential for practical applications. The present research offers a novel binary solid solution for pulse power devices, and emphasizes the polarization competitions strategy as a new reference for optimizing the energy storage performance of relaxor ferroelectrics.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120943"},"PeriodicalIF":8.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631428","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}

{"title":"Fast scanning calorimetry: From thermal analysis to glass design","authors":"Q. Cheng ,&nbsp;Y.H. Sun ,&nbsp;J. Orava ,&nbsp;W.H. Wang","doi":"10.1016/j.actamat.2025.120940","DOIUrl":"10.1016/j.actamat.2025.120940","url":null,"abstract":"<div><div>This work shows that fast differential scanning calorimetry can be used as an engineering fast-probing tool for predictive glass design rather than for thermal analysis only. The examination of Au-based metallic-glass jewelry reveals different types of glassy states that can be achieved by controlling the cooling rate, quenching temperature, annealing temperature, and annealing time. These different states of the same composition are glasses with and without nuclei, and with crystals. In particular, the formation of nuclei can be controlled by the cooling rate, quenching temperature, or annealing parameters, leading to significant differences in the crystallization mechanism. This offers the opportunity to adjust various iso-configurational glassy states, rather than compositions, to achieve a broad range of properties suitable for different applications, such as tough and deformable structural glasses, stable glasses for additive manufacturing, or metallic-glass-nanocrystalline composites with excellent soft magnetic properties. A methodology for constructing thermal-processing maps, readily established via fast differential scanning calorimetry, guiding materials production is provided.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"289 ","pages":"Article 120940"},"PeriodicalIF":8.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631424","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}