Journal of the American Ceramic Society最新文献_第9页

Atomic-scale oxidation mechanism of high-entropy carbides via density functional theory and ab initio molecular dynamics 基于密度泛函理论和从头算分子动力学的高熵碳化物原子尺度氧化机理研究

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI: 10.1111/jace.20448

Yang Bai, Yuxin Liang, Juan Bi, Baoning Cui, Zhaopeng Lu, Huangxuan Wang, Xixi You, Bangsheng Li

{"title":"Atomic-scale oxidation mechanism of high-entropy carbides via density functional theory and ab initio molecular dynamics","authors":"Yang Bai, Yuxin Liang, Juan Bi, Baoning Cui, Zhaopeng Lu, Huangxuan Wang, Xixi You, Bangsheng Li","doi":"10.1111/jace.20448","DOIUrl":"https://doi.org/10.1111/jace.20448","url":null,"abstract":"High-entropy carbides (HECs) are increasingly recognized as promising materials for high-temperature applications, thanks to their remarkable mechanical properties and resistance to oxidation. This study investigates the initial oxidation mechanisms of HEC (Zr₀.₂₅Hf₀.₂₅Nb₀.₂₅Ta₀.₂₅)C through density functional theory and ab initio molecular dynamics simulations. Our results indicate that the (100) surface exhibits the highest stability, where oxygen molecules dissociate into atoms that preferentially adsorb at the threefold hollow site. Further analysis shows that oxygen atoms preferentially bond with Zr and Hf atoms, leading to the formation of oxides. The interaction between oxygen and the surface exhibits mixed ionic–covalent characteristics. Furthermore, oxygen atoms diffuse from the surface to subsurface octahedral sites via tetrahedral interstitial sites, with a migration barrier slightly above that of corresponding binary carbides. This research enhances our understanding of the oxidation resistance in HECs.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Blue/blue–violet-emitting phosphate phosphors for full-spectrum white light-emitting diodes 全光谱白光发光二极管用蓝色/蓝紫色磷光体

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI: 10.1111/jace.20442

Shuifu Liu, Rujun Yang, Rong-Jun Xie

{"title":"Blue/blue–violet-emitting phosphate phosphors for full-spectrum white light-emitting diodes","authors":"Shuifu Liu, Rujun Yang, Rong-Jun Xie","doi":"10.1111/jace.20442","DOIUrl":"https://doi.org/10.1111/jace.20442","url":null,"abstract":"Violet light, a component of sunlight, is critical for human health, but it is usually ignored in classic white light-emitting diodes (LEDs) that are fabricated by pumping green, yellow, or red phosphors by blue LEDs. To realized full-spectrum white LEDs for healthy lighting, it is required to replace blue LEDs by near-ultraviolet (n-UV) or violet LEDs to pump multi-color phosphors. Herein, we reported blue and/or blue–violet phosphors of Na3KMg7P6O24:Eu2+ (NKMPO:Eu2+) and Na3K1–ySryMg7–yLiyP6O24:Eu2+ (NKSMLPO:Eu2+) that can be efficiently excited by n-UV and violet LEDs. The NKSMLPO:Eu2+ phosphor (y = 0.1), showing a small thermal quenching, had a photoluminescence quantum yield of 64.9% and 41.2% under 365 and 405 nm excitation, respectively. Full-spectrum white LEDs were obtained by combining n-UV or violet LEDs with the blue/blue–violet-emitting NKSMLPO:Eu2+ and other commercial phosphors, which show a correlated color temperature of 4285–4705 K and a maximal color rendering index of 98.4. It confirms that the NKSMLPO:Eu2+ phosphors can be adopted as a violet light filler for producing sunlight-like white LEDs.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved temperature coefficient of resistivity in La0.67Ca0.25-xSr0.08AgxMnO3 (0.06 ≤ x ≤ 0.12) polycrystalline ceramics via Ag doping Ag掺杂提高了La0.67Ca0.25-xSr0.08AgxMnO3（0.06≤x≤0.12）多晶陶瓷的电阻率温度系数

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI: 10.1111/jace.20456

Jiachen Wang, Jiankun Sun, Zihao Chen, Yao Wang, Jiamei Han, Haitao Wang, Xiaolu Liang, Zhenyu Wang, Zimeng Pan, Jun Ma, Xuexing Jiang, Xin Gu, Xiang Liu

{"title":"Improved temperature coefficient of resistivity in La0.67Ca0.25-xSr0.08AgxMnO3 (0.06 ≤ x ≤ 0.12) polycrystalline ceramics via Ag doping","authors":"Jiachen Wang, Jiankun Sun, Zihao Chen, Yao Wang, Jiamei Han, Haitao Wang, Xiaolu Liang, Zhenyu Wang, Zimeng Pan, Jun Ma, Xuexing Jiang, Xin Gu, Xiang Liu","doi":"10.1111/jace.20456","DOIUrl":"https://doi.org/10.1111/jace.20456","url":null,"abstract":"Oxides with perovskite structures have received extensive research attention due to their fascinating physical properties. In this study, polycrystalline ceramics of La0.67Ca0.25-xSr0.08AgxMnO3 (LCSAMO, x = 0.06, 0.08, 0.10, and 0.12) were obtained by changing the previous sol-gel preparation process parameters. The results show that LCSAMO ceramics are orthogonal perovskite structures with a space group of Pnma. With increasing x, the grain size, lattice constants, Mn-O bond length (dMn-O), and Mn-O-Mn bond Angle (θMn-O-Mn) are slightly affected. When x = 0.08, the average grain size achieved a maximum value of 8.84 µm, which enhanced the intergranular connectivity. The Mn4+/(Mn3++Mn4+) ratio was the maximum value of 30.26% when x = 0.08, where the double exchange (DE) mechanism was the strongest among the four samples and optimized the electrical transport properties. Ag doping induces distortion in MnO6 octahedron. The electrical transport properties of the ceramics were improved by the combined effect of the distortion and DE mechanism. The temperature coefficient of resistivity (TCR) achieved the maximum value of 24.07% K−1 at 284.91 K. The results of this work provide a theoretical basis for Ag doping at the A-site and thus obtaining lanthanide perovskite manganese oxide with high TCR.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing mechanical properties of Er2O3–Al2O3–SiO2 glass–ceramics for advanced substrate application 提高Er2O3-Al2O3-SiO2微晶玻璃的力学性能

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI: 10.1111/jace.20445

Daimeng Chen, Chao Chen, Bo Li

引用次数: 0

Correction: Boron-dependent microstructural evolution, thermal stability, and crystallization of mechanical alloying derived SiBCN 修正：硼依赖的显微组织演变、热稳定性和机械合金衍生的SiBCN的结晶

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI: 10.1111/jace.20430

Daxin Li, Zhihua Yang, Dechang Jia, Delong Cai, Shengjin Wang, Qingqing Chen, Yu Zhou, Dongli Yu, Yongjun Tian

{"title":"Correction: Boron-dependent microstructural evolution, thermal stability, and crystallization of mechanical alloying derived SiBCN","authors":"Daxin Li, Zhihua Yang, Dechang Jia, Delong Cai, Shengjin Wang, Qingqing Chen, Yu Zhou, Dongli Yu, Yongjun Tian","doi":"10.1111/jace.20430","DOIUrl":"https://doi.org/10.1111/jace.20430","url":null,"abstract":"In this paper, the amorphous boron-rich SiBCN powders were prepared by high-energy ball-milling of the mixtures of inorganic Si, graphite, h-BN, and boron. The solid-state amorphization, thermal stability, and crystallization of the resulting SiBCN powders were studied in detail. Results showed that mechanical alloying can drive solid-state amorphization but also can be an initiation step for the nucleation of few SiC nanocrystals. The amorphous networks containing Si-C, C-B, C-C, C-N, BN, and C-B-N bonds are detected; however, solid-state NMR further confirms the formation of a new chemical environment around B atoms, BC3. The increases in boron content improve the thermal stability of SiBCN ceramics but weaken their oxidation resistance. Nano-SiC crystallizes first while BN(C) forms subsequently. Increasing boron content promoting SiC crystallization may result from the reduced hindering effects of B-N-C nanodomains that retard SiC crystallization.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jace.20430","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Preparation of high pressure hard anodized aluminum oxide coating on 6061 aluminum alloy 6061铝合金高压硬质阳极氧化氧化铝涂层的制备

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI: 10.1111/jace.20454

Fan Yang, Guangming Xu, Ping Liu, Zhihao Nie, Hongkang Pan, Hailin Lu

{"title":"Preparation of high pressure hard anodized aluminum oxide coating on 6061 aluminum alloy","authors":"Fan Yang, Guangming Xu, Ping Liu, Zhihao Nie, Hongkang Pan, Hailin Lu","doi":"10.1111/jace.20454","DOIUrl":"https://doi.org/10.1111/jace.20454","url":null,"abstract":"Hard anodized aluminum oxide coating was prepared on the surface of 6061 aluminum alloy by anodizing technology, and the effects of different anodizing voltages on the coating structure and properties were systematically studied, aiming to prepare high-quality coatings with excellent wear resistance and corrosion resistance. The microstructural analysis and wear and corrosion resistance tests of the coatings prepared at different voltages showed that under the conditions of 120 and 180 V, the coating did not form a complete nanoporous structure, and the coating thickness was low, and the performance was weak. In contrast, the coatings prepared under the conditions of 240, 300 and 360 V showed a complete nanoporous structure and higher thickness, and the content of soft Al2O3 particles on the coating surface gradually increased with the increase of voltage. It is worth noting that the 240 V sample showed the best wear and corrosion resistance. This is mainly due to its comprehensive advantages such as high coating thickness, low roughness, high hardness, and low porosity. This study provides important experimental basis and technical support for the optimization design and subsequent application of high-performance coatings on aluminum alloy surfaces.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural origins of the mixed modifier effect on hardness in aluminosilicate glass 混合改性剂对铝硅酸盐玻璃硬度影响的结构根源

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-21 DOI: 10.1111/jace.20437

Hongyeun Kim, John C. Mauro

{"title":"Structural origins of the mixed modifier effect on hardness in aluminosilicate glass","authors":"Hongyeun Kim, John C. Mauro","doi":"10.1111/jace.20437","DOIUrl":"https://doi.org/10.1111/jace.20437","url":null,"abstract":"Understanding the correlations among glass structure, composition, and mechanical properties, particularly hardness, is crucial for both academic research and practical applications. However, comprehending the underlying structural mechanisms dictating the hardness and plastic deformation of glasses remains a challenge. In this study, we divide hardness into two components: Young's modulus and the plastic-to-total indentation work ratio. Given the intriguing nonlinear convex trend in hardness while Young's modulus remains constant, a phenomenon known as the mixed modifier effect, our primary focus is the plastic-to-total indentation work ratio. By applying pure shear deformation within molecular dynamics simulations, the flow stress demonstrates a linear correlation with Hv/<math>\u0000 <semantics>\u0000 <mi>Y</mi>\u0000 <annotation>$Y$</annotation>\u0000 </semantics></math> and with the plastic-to-total indentation work ratio. Additionally, in our structural analysis, we identify that the average coordination numbers of network modifiers are key factors driving the nonlinear trend observed in both hardness and simulated flow stress.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jace.20437","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regulating the field-induced AFE-FE transition in NaNbO3 from the perspective of powder surface energy 从粉末表面能的角度调控NaNbO3的场致fe - fe转变

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-21 DOI: 10.1111/jace.20433

L. G. Wang, Z. H. Guan, Q. Zhang, M. S. Wang, C. M. Zhu, G. B. Yu, R. Wang, H. Cui, X. L. Jiang, X. F. Su

{"title":"Regulating the field-induced AFE-FE transition in NaNbO3 from the perspective of powder surface energy","authors":"L. G. Wang, Z. H. Guan, Q. Zhang, M. S. Wang, C. M. Zhu, G. B. Yu, R. Wang, H. Cui, X. L. Jiang, X. F. Su","doi":"10.1111/jace.20433","DOIUrl":"https://doi.org/10.1111/jace.20433","url":null,"abstract":"Sodium niobate (NaNbO3, NN) has drawn growing attention for its wide application in engineering fields due to the room-temperature antiferroelectric phase with an orthorhombic Pbcm space group, which is generally known as the P phase. However, a ferroelectric Q phase is commonly induced out of P phase under the applied electric field leading to a coexistence of these two phases. Accordingly, this irreversible transition reported in previous literature causes the unobservable double polarization hysteresis loops of NN at ambient conditions. Thus, it has significant implications in investigating the formation of ferroelectric or antiferroelectric phase and the corresponding field-induced transition. Herein, the content ratio of P/Q phase in polycrystalline NN ceramics is effectively regulated from the perspective of powder surface energy, through adjusting the ball-milling time during solid-state reaction process. Moreover, the physical mechanism of field-induced transition is explored based on analyzing the room-temperature ferroelectric properties and the in situ Raman spectra with varying electric field. This work provides feasible strategy of modulating the inversion between ferroelectric and antiferroelectric phases in NN. The analysis of theoretical results can facilitate further design of NN-based materials for actual application in technologies.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Factors affecting the rheology of cement-based composites: A review 影响水泥基复合材料流变学的因素综述

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-21 DOI: 10.1111/jace.20429

Astha Sharma, Sanchit Gupta, Momin Noman Husain, Sandeep Chaudhary

{"title":"Factors affecting the rheology of cement-based composites: A review","authors":"Astha Sharma, Sanchit Gupta, Momin Noman Husain, Sandeep Chaudhary","doi":"10.1111/jace.20429","DOIUrl":"https://doi.org/10.1111/jace.20429","url":null,"abstract":"Rheology, the study of flow and deformation in materials, is key to understanding the flow behavior of fresh cementitious materials, which, in turn, influences their hardened properties and durability. The rheology of cementitious mixes is complex and significantly impacts their fresh-state application in construction. Understanding and controlling the factors affecting rheology is crucial for optimizing mix designs and improving construction practices. This study provides an in-depth understanding of cementitious mix rheology, factors influencing rheology, optimization, and its correlation with mathematical models. The paper presents the impact of internal factors, such as water–cement ratio and cement fineness, as well as external factors, like temperature, shear rate, and time, on the rheology of cementitious materials. The study examines how these factors influence fundamental rheological characteristics and behaviors such as thixotropy and shear thinning. It outlines ways to optimize mix designs, enhance workability, and improve emerging technologies like 3D concrete printing. Additionally, it correlates available mathematical models with the identified influencing factors. This analysis fills a gap in existing literature and contributes to advancing concrete technology and its practical applications, paving the way for innovative solutions in the construction industry. It also provides directions for future research in rheological behavior modeling, potentially leading to more efficient and sustainable concrete construction practices.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural stability of the robust GdYTi2O7 pyrochlore under high pressure 强韧GdYTi2O7焦绿石在高压下的结构稳定性

IF 3.5 3区材料科学

Journal of the American Ceramic Society Pub Date : 2025-02-21 DOI: 10.1111/jace.20444

Yogendar Singh, Vivek Kumar, Tijo Vazhappilly, Himanshu Kumar Poswal, K. K. Pandey, Pawan Kumar Kulriya

{"title":"Structural stability of the robust GdYTi2O7 pyrochlore under high pressure","authors":"Yogendar Singh, Vivek Kumar, Tijo Vazhappilly, Himanshu Kumar Poswal, K. K. Pandey, Pawan Kumar Kulriya","doi":"10.1111/jace.20444","DOIUrl":"https://doi.org/10.1111/jace.20444","url":null,"abstract":"Complex ceramics with pyrochlore (A2B2O7) and defect-fluorite ((A, B)4O7) type structures experience structural modifications under high pressure. Here, we used mechanical milling and sintering followed by compression in diamond anvil cell to determine the high-pressure behavior using in-situ synchrotron diffraction. Raman spectroscopy and X-ray diffraction at ambient pressure confirm the pyrochlore phase of as-prepared GdYTi2O7 ceramic. In-situ high-pressure experiments reveal no structural phase transition in GdYTi2O7 pyrochlore up to approximately 50 GPa. The variation in the x positional coordinate of O48f oxygen and cation–anion bond lengths shows that disordering occurs at high pressure above ∼43 GPa. The Rietveld refinement results indicate the pyrochlore phase of GdYTi2O7 ceramic at the highest pressure of ∼50 GPa. Compared to Y2Ti2O7, the equal substitution of Y3+ and Gd3+ at the A-site increases phase stability at high pressures. The experimental results indicate that mainly cation disordering occurs with increasing pressure, and lower compressibility of < Ti–O48f > bonds should play a significant role in the robustness of GdYTi2O7 pyrochlore to sustain pyrochlore structure up to very high pressures. DFT-derived cation–anion bond lengths and bulk modulus value agree with the experimental results in supporting the robustness of the GdYTi2O7 pyrochlore.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 6","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0