Acta Materialia最新文献

{"title":"Phase transition of NaNbO3-based antiferroelectric ceramics: Doping research based on DFT calculation","authors":"Yile Yang ,&nbsp;Jing Shang ,&nbsp;Jinbo Zhang ,&nbsp;Pengfan Lv ,&nbsp;Jiachen Li ,&nbsp;Yiting Hui ,&nbsp;Lei Zhang ,&nbsp;Min Chen ,&nbsp;Shaobin Zhang ,&nbsp;Man Yu ,&nbsp;Yongping Pu","doi":"10.1016/j.actamat.2026.121967","DOIUrl":"10.1016/j.actamat.2026.121967","url":null,"abstract":"<div><div>The practical application in electronic devices of NaNbO₃ (NN)-based ceramics by utilizing the antiferroelectric (AFE) behavior is highly limited by its phase instability and insufficient breakdown strength. Traditional approaches rely heavily on extensive experimental validation, and the fundamental mechanisms remain poorly understood. To address these challenges, density functional theory (DFT) calculations were performed in the present study to predict the effects of Sm doping at the A-site of NN on structural and energy variation. The calculated results indicate that Sm doping stabilizes the AFE-R phase by lowering its formation energy relative to the FE-Q and AFE-P phases, revealing a clear preference toward the AFE-R configuration. Guided by theoretical predictions, Na_1-<em>_x</em>Sm<em>_x</em>NbO_3+δ ceramics were designed and synthesized in this study to verify the calculated results. Experimental results indicate that substitutional doping at the A-site could effectively help to stabilize the AFE-R phase. With the increasing doping concentration, the substitution effect of Sm³⁺ becomes more pronounced, leading to an enhanced relaxor behavior in the AFE-R phase and resulting in a slim <em>P</em>-<em>E</em> loop, consistent with the larger calculated ∆<em>E</em> values. Additionally, the SmNbO₄ phase with low dielectric constant and high breakdown strength gradually precipitates at the grain boundaries, contributing to improved electrical performance of the ceramics. The potential mechanism of the improved breakdown strength and the energy storage performance were further revealed by electron paramagnetic resonance (EPR) and piezoresponse force microscopy (PFM) measurements. These results provide theoretical insights and experimental evidence for the development of lead-free ceramics with high-performance energy storage capabilities.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121967"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047857","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":"Tailoring microstructures with mild magnetic-field processing: A case study of CuNiFe alloys","authors":"X. Zhang ,&nbsp;C.D. Woodgate ,&nbsp;G. Hadjipanayis ,&nbsp;J.B. Staunton ,&nbsp;L.H. Lewis","doi":"10.1016/j.actamat.2026.121965","DOIUrl":"10.1016/j.actamat.2026.121965","url":null,"abstract":"<div><div>Combined experimental and computational investigations of the CuNiFe spinodal system confirm that application of a mild magnetic field during thermal treatment alters elemental redistribution and the resulting microstructure, relative to that obtained from zero-field annealing. Spinodal decomposition of a Cu₄₀Ni₄₂Fe₁₈ alloy was initiated during thermal treatment at 773 K, conducted either under zero field or modest (60 mT) magnetic field conditions for up to 200 h. Periodic (∼10 nm) chemical modulations into Cu-rich and NiFe-rich regions were observed under both conditions, with the amplitude and wavelength of the segregated regions increasing with treatment time. However, magnetic field annealing resulted in a more than twofold increase in the amplitude of elemental modulations relative to zero-field conditions – consistent with enhanced diffusional fluxes during spinodal decomposition – while the modulation wavelength remained largely unaffected. These microstructural differences are reflected in various extrinsic magnetic properties. In parallel, first-principles DFT calculations indicate that long-range ferromagnetic order, as induced by an applied magnetic field, substantially alters the strength and nature of atomic interactions, enhancing the thermodynamic instability of the CuNiFe solid solution. Collectively, these results suggest that incorporating a mild (millitesla-level) magnetic field – distinct from the strong (tesla-level) fields commonly used in prior studies – during thermal processing has the potential to deliver enhanced control of microstructures for targeted engineering outcomes.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121965"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047862","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":"Operando-spectroscopy revealing interfacial two-coordinated ordered water in electrochemical activation of Ni(OH)₂","authors":"Jingjuan Li ,&nbsp;Zhiqi Zhu ,&nbsp;Taowen Dong ,&nbsp;Yuxiang Gao ,&nbsp;Aofei Wei ,&nbsp;Xiangyu Wu ,&nbsp;Binbin Yang ,&nbsp;Wenwen Li ,&nbsp;Xiaolong Li ,&nbsp;Tao Gan ,&nbsp;Wei Zhang ,&nbsp;Weitao Zheng","doi":"10.1016/j.actamat.2026.121970","DOIUrl":"10.1016/j.actamat.2026.121970","url":null,"abstract":"<div><div>Elucidating the underlying mechanisms of electrochemical activation lays the foundation to establish structure-performance correlation in electrochemical systems. The available reports mainly focus on structural changes of the electrode itself. However, the corresponding evolution of the electrode-electrolyte interface; particularly the reconstruction of the interfacial hydrogen-bond networks, is frequently overlooked. Herein, we report the discovery of dynamic reconfigurations at the electrode-electrolyte interface in an electrochemical activation of the Ni(OH)₂ electrode. By using a suite of spectroscopy analyses, we demonstrate that the pristine Ni(OH)₂ can be dynamically converted into oxygen-vacancy rich Ni(OH)@NiOOH via two distinct stages. Furthermore, <em>operando</em> Raman spectroscopy and molecular dynamics (MD) simulations indicate that the interfacial four-coordinated, randomly distributed hydrogen-bonded water evolves into two-coordinated, more ordered hydrogen-bonded water. As a consequence, it facilitates OH^– transport across the electrode-electrolyte interface, leading to an extraordinary 5-fold enhancement of specific capacity. Our results reinvent the current cognition of electrochemical activation. That is, both the evolution of the electrode and the reconstruction of the interfacial water are fully involved, leads to the formation of a new solid-liquid interface.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121970"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072998","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":"CuCoCrRuMo HEA achieving Cl− repulsion and Mg resource recovery in industrial-current-density seawater electrolysis","authors":"Hao He ,&nbsp;Zhiyuan Chen ,&nbsp;Wansen Ma ,&nbsp;Qigang Chen ,&nbsp;Qian Li ,&nbsp;Xuewei Lv ,&nbsp;Jie Dang","doi":"10.1016/j.actamat.2026.121971","DOIUrl":"10.1016/j.actamat.2026.121971","url":null,"abstract":"<div><div>Seawater-electrolysis is a promising green method for hydrogen production, but the high corrosiveness of seawater and magnesium hydroxide precipitation during electrolysis quickly deactivate the cathode. Therefore, developing efficient and low-cost electrocatalysts remains a key challenge in this field. Herein, we develop a high-entropy alloy (CuCoCrRuMo HEA) catalyst for seawater electrolysis hydrogen production, simultaneously achieving the recovery of magnesium resources from seawater. The formation of MoO₄²⁻ during the OER process effectively repels Cl⁻, mitigating catalyst corrosion. Additionally, the Cr₂O₃ enhances the corrosion resistance of the catalyst. The alloy also facilitates the deposition and recovery of Mg(OH)₂ by repelling Mg²⁺, enabling efficient utilization of seawater resources. In 1 M KOH, the CuCoCrRuMo HEA exhibits overpotentials of 402 mV for HER and 450 mV for OER at the current density of 1000 mA cm⁻². In 1 M KOH + 0.5 M NaCl (simulated seawater), the overpotentials decrease to 368 mV for HER and 430 mV for OER. Moreover, sustaining HER and OER performance for 1000 h at the same high current density in 1 M KOH + 0.5 M NaCl. These outstanding electrochemical performances highlight the potential of the CuCoCrRuMo HEA catalyst for efficient and stable seawater electrolysis and the comprehensive utilization of seawater resources.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121971"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071507","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":"Rb(Cd,Zn)4As3 as a new n-type Zintl phase thermoelectric compound","authors":"Keigo Ono ,&nbsp;Yosuke Goto ,&nbsp;Hidetomo Usui ,&nbsp;Masayuki Murata ,&nbsp;Satoshi Tsutsui ,&nbsp;Kazuhiko Kuroki ,&nbsp;Yoichi Kamihara ,&nbsp;Chul-Ho Lee","doi":"10.1016/j.actamat.2026.121968","DOIUrl":"10.1016/j.actamat.2026.121968","url":null,"abstract":"<div><div>Despite 143-Zintl phase was recently found to be a new family of high performance thermoelectric compounds, the lack of n-type restricts its potential for application in practical thermoelectric modules. Here we report a novel n-type 143-Zintl phase compound of RbCd<span><math><msub><mrow></mrow><mrow><mn>4</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Zn<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> as a counterpart. The samples were prepared using solid-state reactions and densified via hot pressing. The Seebeck coefficients were negative, demonstrating that they represent n-type conductors. The Hall carrier concentration was found to decrease upon Zn doping, suggesting that the band gap opened upon doping, consistent with the results of first-principles calculations. Notably, the Hall mobility was extremely high, namely <span><math><msub><mrow><mi>μ</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span> = 2.0 × 10³ cm²/Vs at <span><math><mi>T</mi></math></span> = 300 K, originating from the electrical conductivities of the Cd 5s and As 4p electrons. On the other hand, a low lattice thermal conductivity was obtained, i.e., the minimum value of 0.56 W/mK (<span><math><mi>x</mi></math></span> = 0.4) at <span><math><mi>T</mi></math></span> = 624 K, and the maximum value of the dimensionless figure-of-merit (<span><math><mrow><mi>Z</mi><mi>T</mi></mrow></math></span>) was determined to be 0.43 (<span><math><mi>x</mi></math></span> = 0.4) at <span><math><mi>T</mi></math></span> = 620 K. These results pave the way for the development of high-performance n-type thermoelectric compounds of the 143-Zintl phase.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121968"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071569","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":"AlCoCrFeNi2.1 eutectic high entropy alloy: defect analysis, microstructural stability and ion irradiation resilience","authors":"Yuval Hodaya Malinker ,&nbsp;Shai Salhov ,&nbsp;Malki Pinkas ,&nbsp;Vladimir Ezersky ,&nbsp;Olga Girshevitz ,&nbsp;Mauricio Sortica ,&nbsp;Johan Oscarsson ,&nbsp;Daniel Primetzhofer ,&nbsp;Louisa Meshi","doi":"10.1016/j.actamat.2026.121985","DOIUrl":"10.1016/j.actamat.2026.121985","url":null,"abstract":"<div><div>The AlCoCrFeNi_2.1 eutectic high entropy alloy (EHEA) features a dual-phase lamellar microstructure composed of ordered L1₂ and B2 phases, offering a unique combination of strength, ductility, and thermal stability. This study investigates the microstructural evolution, phase stability, and irradiation resilience of AlCoCrFeNi_x alloys with x = 1.9, 2.1, and 2.6. Advanced electron microscopy techniques revealed composition-dependent microstructure and confirmed the eutectic nature of the x = 2.1 alloy. Thermomechanical processing via cold rolling and annealing preserved phase ordering and enhanced mechanical properties. Irradiation of transmission electron microscopy (TEM) samples with Ne ions at doses up to 1.5 dpa enabled precise microstructure and defect analysis by comparing pre- and post-irradiation states of the same samples. The L1₂ phase exhibited dose-dependent disordering (assessed via evaluation of the fraction of 〈110〉-type dislocations), while the B2 phase retained its ordered structure, showing localized disorder and anti-phase boundaries. As a function of dose, a significant decrease in the network dislocation density (excluding dislocation loops) was observed in L1₂. On the other hand, this phase exhibited dose-dependent increase in both the density and size of dislocation loops. The B2 phase exhibited a similar effect, although the change was more moderate compared to L1₂. Semi-coherent L1₂/B2 boundaries, initially rich in dislocations, retained the Kurdjumov–Sachs orientation relationship post-irradiation, although dislocations vanished and stacking faults occasionally formed. These findings elucidate phase-specific radiation damage mechanisms and confirm the superior irradiation tolerance and structural integrity of AlCoCrFeNi_2.1, highlighting its potential for nuclear structural applications.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121985"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122152","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":"High-entropy trace intercalation in layered semiconductors: Synergistically optimized thermoelectric performance via entropy-driven transport decoupling","authors":"Hongxiang Chen ,&nbsp;Shiyu Li ,&nbsp;Xiaochun Wen ,&nbsp;Jing Zhang ,&nbsp;Bing Xiao ,&nbsp;Yunfeng Su ,&nbsp;Hengzhong Fan ,&nbsp;Yongsheng Zhang","doi":"10.1016/j.actamat.2026.121984","DOIUrl":"10.1016/j.actamat.2026.121984","url":null,"abstract":"<div><div>Intercalation effectively enhances the thermoelectric performance of layered semiconductors. However, conventional strategies employing a single metal element at low concentrations yield limited improvements, typically failing to achieve a <em>zT</em> value greater than 0.5 in intrinsic transition metal dichalcogenides (TMDCs). Here, we propose a ​high-entropy trace intercalation​ strategy by incorporating multi-component metal atoms into TiS₂. Remarkably, a high thermoelectric figure of merit (<em>zT</em> ≈ 0.7 at 723 K) is realized, attributed to the simultaneous optimization of thermal and electronic properties: reduced total thermal conductivity <em>κ</em> and high power factor (<em>PF</em>) with enhanced weighted mobility. Key characteristics at the optimized intercalation content (<em>x</em> = 0.02) include minimized lattice thermal conductivity (<em>κ</em>_L), sound velocity, and elastic moduli. The outstanding performance stems from ​entropy-engineering, where optimized intercalation (∼2%) induces a substantial entropy enhancement by 33%, generating pronounced lattice disorder and anharmonicity. Critically, this strategy avoids the increase in <em>κ_L</em> typically associated with higher intercalant concentrations while maintaining low effective charge doping, thereby minimizing <em>κ</em>. Meanwhile, favorable charge transfer from the intercalation layer to the conduction layers, along with entropy-driven band renormalization, enhances the electrical transport properties. This work establishes high-entropy trace intercalation as a universal paradigm for decoupling electronic and thermal transport in layered thermoelectrics.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121984"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101595","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":"Lamellar architecture and resultant two-way memory mechanism in NiTi alloy by magnetic field-assisted additive manufacturing","authors":"Weisi Cai ,&nbsp;Hongwei Ma ,&nbsp;Tao Chen ,&nbsp;Pengxu Li ,&nbsp;Sizhan Liu ,&nbsp;Changhui Song ,&nbsp;Xiaoqiang Li ,&nbsp;Chao Yang","doi":"10.1016/j.actamat.2026.121963","DOIUrl":"10.1016/j.actamat.2026.121963","url":null,"abstract":"<div><div>Additive manufacturing (AM) enables transformative design freedom for metallic components, while field-assisted AM provides an expanded space for microstructure control. Herein, we report on magnetic field-assisted laser powder bed fusion of NiTi shape memory alloys, which can introduce unprecedented lamellar architecture and enhance two-way shape memory effect (TWSME). By coupling unidirectional scanning strategy with 50 mT vertical static magnetic field, NiTi specimen (MS) exhibits a directional lamellar architecture (widths ∼185 μm) comprising alternating B19′ martensite and B2 austenite. Fundamentally, the lamellae originate from thermoelectric magnetohydrodynamic effects: Lorentz forces arising from the interaction between thermoelectric currents and the applied magnetic field induce a melt pool deflection of approximately 33.6°. This deflection converts the austenite and martensite regions from a disordered alternation into a well-ordered lamellar architecture. After identical thermomechanical training, the specimen MS exhibits far higher TWSME strains (0.97 % for compression and 0.75 % for tension) than the corresponding ones for the counterpart without magnetic field assistance. Microstructural analysis reveals that the lamellar architecture facilitates directional internal stress fields, enabling alternating favored correspondence variant pair (CVP) zones and strain accommodation zones. The favored CVP zones enhance recoverable strain, while the strain accommodation zones alleviate the lattice incompatibility, collectively contributing to the superior TWSME. This work provides fundamental insights into field-assisted microstructure tailoring and performance enhancement in AM.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121963"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032915","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":"Architecting Ta-V-enriched local chemical ordering for strength-ductility synergy in multi-principal element alloys","authors":"Zheng Li ,&nbsp;Zhichao Meng ,&nbsp;Dingxin Liu ,&nbsp;Chang Liu ,&nbsp;Xiaowei Zuo","doi":"10.1016/j.actamat.2026.121960","DOIUrl":"10.1016/j.actamat.2026.121960","url":null,"abstract":"<div><div>Local chemical ordering (LCO) is a key microstructural feature in multi-principal element alloys (MPEAs), critically influencing their mechanical properties. However, the mechanisms of LCO formation and their interactions with dislocations remain unclear, and effective strategies for architecting LCOs to enhance both strength and ductility are lacking. In this work, we achieve controlled formation of novel Ta-V-enriched LCOs within a Ti-Zr-Nb-Ta-V alloy system, and investigate their formation mechanisms and interactions with dislocations through a combination of experimental characterization, thermodynamic calculations, and molecular dynamics simulations. Our results reveal that these LCOs, which act as precursors to the C15 Laves phase, exhibit two distinct morphologies: string-like and cluster-like, whose prevalence depends on V content. Mobile dislocations interact with string-like and cluster-like LCOs via shearing and bypassing mechanisms, respectively. Cluster-like LCOs provide stronger and more sustainable barriers to dislocation motion than their string-like counterparts. Importantly, they not only strengthen the matrix by impeding dislocation motion but also enhance ductility by promoting dislocation multiplication and activating multiple slip systems. Dislocation loops generated by interactions with cluster-like LCOs act as Frank-Read sources, expanding during deformation to facilitate further activity. Consequently, the V15 alloy, rich in cluster-like LCOs, exhibits synergistic mechanical improvements over the V5 alloy, achieving a yield strength of 1.04 GPa, ultimate tensile strength of 1.2 GPa, and ductility of 20.6 %. This work provides fundamental insights into LCO-driven deformation mechanisms and opens a pathway for designing high-performance MPEAs through precise LCO control.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121960"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032912","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":"Low Young’s modulus achieved by anelastic relaxation arising from reversible atomic shuffling in bcc Ti–Nb alloys","authors":"Masakazu Tane ,&nbsp;Keigo Morita ,&nbsp;Eisuke Miyoshi ,&nbsp;Takumi Hiramatsu","doi":"10.1016/j.actamat.2026.121969","DOIUrl":"10.1016/j.actamat.2026.121969","url":null,"abstract":"<div><div>Metastable body-centered cubic (bcc) Ti alloys are attractive biomedical implant materials because they exhibit a low elastic modulus which helps mitigate bone degradation. The low elastic modulus in these alloys is believed to be correlated with a low-stability bcc structure. However, the physical nature of this correlation remains unclear. In this study, we show that the low elastic modulus of bcc Ti–Nb alloys originates from the anelastic relaxation driven by reversible atomic shuffling events that act as precursors to the <span><math><mi>ω</mi></math></span> (hexagonal) and <span><math><msup><mrow><mi>α</mi></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup></math></span> (orthorhombic) martensitic transformations. A combination of molecular-dynamics simulations and measurements of Young’s modulus and internal friction revealed that the reversible atomic shuffling events have a low average activation energy of 0.20 eV, leading to significant anelastic relaxation even at room temperature (<span><math><mo>∼</mo></math></span>300 K), thereby lowering the elastic modulus. The reversible atomic shuffling events occur in sub-nanometer-scale, low-stability bcc regions that are depleted in the bcc-stabilizing element Nb. These regions originate from quenched-in statistical compositional fluctuations, which exist even when the constitutive elements are randomly distributed. Thus, controlling the reversible atomic shuffling events by manipulating the compositional fluctuations and the resultant local chemical composition is an effective strategy for lowering the elastic modulus of biomedical bcc Ti alloys.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"307 ","pages":"Article 121969"},"PeriodicalIF":9.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185601","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}