Journal of the American Ceramic Society最新文献

{"title":"Understanding of alkali–silica reaction in lime-pozzolana mortar incorporating pumice and borosilicate","authors":"Adhora Tahsin,&nbsp;Ishrat Baki Borno,&nbsp;Taehwan Kim,&nbsp;Warda Ashraf","doi":"10.1111/jace.70168","DOIUrl":"https://doi.org/10.1111/jace.70168","url":null,"abstract":"<p>To assess the efficacy of lime-calcined clay binder in mitigating alkali–silica reaction (ASR) deterioration, this study identifies potential reaction product formation mechanisms in 2-year-old alkaline solution-exposed mortar bars using X-ray diffraction, micro-computed tomography, scanning electron microscopy, and evaluates their influence on mortar performance. The bar samples exhibit only 0.02% ASR-induced expansion, ascribed to the high alumina incorporation from the binder matrix into the initially formed sodium silicate hydrate (N-S-H) gel, enhancing silica polymerization and eventually forming zeolites such as phillipsite and chabazite. These zeolites, with a (Na+K)/Si ratio of 0.2–0.5, can uptake alkali, thus reducing their availability for further reactions. The crystalline ASR product Na-shlykovite is also observed, coexisting with the zeolites and forming at their core. Additionally, pumice inclusion in the binder enhances its ASR mitigation capability by supplying additional alumina and accommodating reaction products within its internal voids, thereby preventing the propagation of shrinkage cracks into the binder matrix. Consequently, including pumice with borosilicate in lime-calcined clay mortar increased its compressive strength by 52% compared with using only borosilicate under prolonged alkaline conditions.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ceramics.onlinelibrary.wiley.com/doi/epdf/10.1111/jace.70168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196865","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}

{"title":"Ultrawide bandgap Sm-based zirconate transparent dielectrics: Phase evolution-driven optical and dielectric enhancement","authors":"Shirui Li,&nbsp;Wenhan Han,&nbsp;Min Gong,&nbsp;Kailei Lu,&nbsp;Fangyu Yi,&nbsp;Junyao Guo,&nbsp;Puchun Wei,&nbsp;Yao Ma,&nbsp;Yucheng Ye,&nbsp;Jianqi Qi","doi":"10.1111/jace.70188","DOIUrl":"https://doi.org/10.1111/jace.70188","url":null,"abstract":"<p>Ultrawide bandgap (UWBG) materials are recognized for their high thermal stability, high breakdown voltages, and transparency, which make them ideal for a variety of optical and electronic devices. This study investigates the phase evolution and its effects on the optical and dielectric properties of samarium-based zirconate (Sm₂Zr₂O₇) transparent dielectric ceramics, with a focus on their potential for advanced optoelectronic applications. The A₂B₂O₇ structure of samarium-based zirconates provides key advantages, including high mechanical stability, tunable optical transparency, and enhanced dielectric performance. Through systematic experimental analysis, we explore how A-site substitution induces phase evolution from defective fluorite to pyrochlore and influences both the optical transparency and dielectric properties. The bandgap of prepared ceramic achieved up to 4.4 eV with high dielectric constant (25.5) and low dielectric loss (0.4). The results demonstrate that controlled phase changes significantly enhance the material's dielectric characteristics, making samarium-based zirconates suitable for applications in transparent capacitors and radiation sensors. Our finding provides valuable insights into the design and optimization of bulk transparent UWBG materials, promoting their use in next-generation optoelectronic devices.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196732","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}

{"title":"Improving mechanical properties of selective laser sintering-printed SiC/Si composites via microspheres with trimodal grains","authors":"Pengze Yang,&nbsp;Lijun Xiong,&nbsp;Guoqiang Wen,&nbsp;Lixia Yang,&nbsp;Zhaofeng Chen,&nbsp;Kai Liu,&nbsp;Ce Sun,&nbsp;Xiguang Gao,&nbsp;Yingdong Song","doi":"10.1111/jace.70169","DOIUrl":"https://doi.org/10.1111/jace.70169","url":null,"abstract":"<p>The dense SiC microspheres with trimodal grains were prepared via electrostatic spraying combined with phase inversion (ES-PI), using SiC particles with original particle sizes of 0.8, 5, 10, 20, and 30 µm. High-performance SiC/Si composites were then fabricated by combining polymer infiltration pyrolysis (PIP) and liquid silicon infiltration (LSI) with selective laser sintering (SLS). The effects of different particle size gradations on the pore structure of ES-PI SiC microspheres, as well as the phase composition, microstructure, and mechanical properties of SiC/Si composites, were systematically investigated. For comparison, commercial SiC particles (∼40 µm) were also used to prepare SiC/Si composites under the same conditions. The results revealed that compared to commercial SiC particles, the SiC microspheres exhibited superior sphericity and flowability. Furthermore, the mechanical properties of SiC/Si composites prepared with SiC microspheres were significantly improved, compared to SiC/Si composites fabricated using commercial SiC particles. The flexural strength and fracture toughness of the material. The flexural strength increased by approximately 26.06%, and the fracture toughness improved by about 11.25%.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196734","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}

{"title":"A/B-site co-doping strategy driven two-phase proportional equilibrium to optimize energy storage property in Bi0.5Na0.5TiO3","authors":"Zihan Ruan,&nbsp;Bing Li,&nbsp;Jingsong Liu","doi":"10.1111/jace.70132","DOIUrl":"https://doi.org/10.1111/jace.70132","url":null,"abstract":"<p>Lead-free perovskite ceramics have emerged as promising candidates for energy storage applications due to their excellent dielectric properties and environmental compatibility. Among them, Bi_0.5Na_0.5TiO₃ (BNT)-based ceramics stand out for large spontaneous polarization (<i>P</i>_S) and high Curie temperature (<i>T</i>_C). However, practical applications of BNT are hindered by challenges such as high dielectric loss and low breakdown electric field strength, which limit their energy storage capabilities. To address the limitations, this work proposes a second component solid solution and dual-site doping strategy with Ca²⁺ substitution at the A-site and Hf⁴⁺ substitution at the B-site, then the 0.65(Bi_0.5Na_0.5)_1-<i>_x</i>Ca<i>_x</i>Hf<i>_y</i>Ti_1-<i>_y</i>O₃-0.35Sr_0.7Bi_0.2TiO₃ (BNC<i>_x</i>H<i>_y</i>T-SBT, <i>x, y</i> = 0, 0.03, 0.05, 0.07, 0.09) ceramics were designed and synthesized. At the optimized composition (<i>x, y</i> = 0.07), BNC_0.07H_0.07T-SBT ceramic exhibits a recoverable energy density of 3.45 J/cm³ under 250 kV/cm electric field, representing more than 30% enhancement in recoverable energy density compared to the undoped BNT–SBT, with an energy efficiency of 83%. Multi-level microstructure characterization and analysis indicates that Ca²⁺/Hf⁴⁺ co-doping stabilizes the TiO₆ octahedral structure, refines grain size and promotes nano-domains formation. In addition, BNC_0.07H_0.07T-SBT ceramic achieves a balanced coexistence of <i>P</i>4bm and <i>R</i>3c phases, significantly enhancing polarization dynamics and relaxor behavior, thereby maximizing energy storage performance. This work provides critical insights into phase engineering and offers a viable strategy for developing high-performance energy storage ceramics.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196678","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}

{"title":"High-performance hybrid supercapacitor using NiFe2O4/rGO/polypyrrole ternary composite derived from Prussian blue analogs","authors":"Md Kasif,&nbsp;Mayanmi Zimik,&nbsp;Saddam Hussain,&nbsp;Meghali Devi,&nbsp;Ranjith Thangavel","doi":"10.1111/jace.70181","DOIUrl":"https://doi.org/10.1111/jace.70181","url":null,"abstract":"<p>The pursuit of energy storage devices with high power and energy density has driven significant advancements in supercapacitor electrode materials. This study develops a ternary NiFe₂O₄/rGO/PPy composite derived from Prussian blue analogs to enhance both the energy density and electrochemical stability of supercapacitors. The incorporation of reduced graphene oxide (rGO) and polypropylene (PPy) significantly improves conductivity and electron transport pathways in NiFe₂O₄. The ternary NiFe₂O₄/rGO/PPy nanocomposite exhibited a gravimetric capacitance of 385 F g⁻¹ at 0.5 A g⁻¹ in 1 M Na₂SO₄, five times higher than that of pristine NiFe₂O₄ under the same three-electrode configuration. An asymmetric hybrid supercapacitor fabricated with NiFe₂O₄/rGO/PPy and activated carbon electrodes achieved a high energy density of 29.2 Wh kg⁻¹ and a power density of 400 W kg⁻¹ (based on the mass of both electrodes). The supercapacitor also exhibited excellent cycling stability, retaining ∼80% of its initial capacitance after 3000 cycles when cycled at 2 A g⁻¹. These findings demonstrate the potential of this strategy to enable advanced energy storage solutions.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196687","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}

{"title":"Atomic-scale structure elucidation of refractory metal carbides derived from metallocene-based preceramics","authors":"Stephanie L. Chua,&nbsp;Haira G. Hackbarth,&nbsp;James F. Ponder Jr.,&nbsp;Nicholas D. Posey,&nbsp;Yuwei Yang,&nbsp;Pierre-Olivier Autran,&nbsp;Matthew B. Dickerson,&nbsp;Timothy L. Pruyn,&nbsp;Nicholas M. Bedford","doi":"10.1111/jace.70178","DOIUrl":"https://doi.org/10.1111/jace.70178","url":null,"abstract":"<p>Polymer-derived ceramics (PDCs) are becoming an alluring class of materials that can incorporate the ceramic chemistries found in ultra-high-temperature ceramics, such as Ti, Zr, and Hf carbides. The use of polymeric materials intrinsically enables processing techniques with a higher degree of complexity in a more straightforward fashion, such as three-dimensional printing. In this contribution, a series of click-derived preceramic polymers (PCPs) was synthesized using azide-modified metallocene monomers and an alkynyl-modified aromatic monomer, with Ti, Zr, and/or Hf serving as the metals of interest. PDCs were generated via pyrolysis at 800, 1100, and 1500°C and thoroughly examined using a range of synchrotron-based scattering and spectroscopy techniques to better couple atomic-scale structure back to precursor chemistry and pyrolysis conditions. Reverse Monte Carlo (RMC) simulations were implemented to model synchrotron datasets for the extraction of structural metrics, such as local coordination numbers (CNs) and bond angle distributions. Heterogeneous RMC approaches were also used to better reflect the multi-phase structure found in these materials. In addition to examining single metal PDCs, the click chemistry approach implemented here enables the ready inclusion of different metallocene monomers, wherein TiZrHf PDCs were synthesized and further examined to determine the structural evolution of these materials. Overall, our work showcases a pathway for accessing atomic-scale structure in these emergent materials, providing the ability to assess structure-property relationships for future materials development.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ceramics.onlinelibrary.wiley.com/doi/epdf/10.1111/jace.70178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196647","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}

{"title":"In-situ reactive joining of silicon carbide ceramics with zirconium disilicide and graphite","authors":"Lin-Lin Zhu,&nbsp;Xu-Hui Chen,&nbsp;Yu-Jian Jian,&nbsp;Chen-Hao Dong,&nbsp;Teng-Fei Li,&nbsp;Jia-Hao Chen,&nbsp;Hua-Tay Lin","doi":"10.1111/jace.70172","DOIUrl":"https://doi.org/10.1111/jace.70172","url":null,"abstract":"<p>High-strength joining of silicon carbide (SiC) ceramics was achieved at relatively low temperatures through in-situ reaction of zirconium disilicide (ZrSi₂) and graphite (C), employed as the joining material. The effects of C content and joining temperature on the microstructure, phase composition, and mechanical properties of the joints were investigated. The interlayer was composed of SiC, zirconium carbide, ZrSi₂, and Si-Zr phases. The shear strength of the joint first increased and then decreased with the increase of C content. When the molar ratio of C/ZrSi₂ was 2, the shear strength measured of the joint, which was conducted at 1450°C by spark plasma sintering, was 178.2 ± 8.6 MPa. Subsequently, the C/ZrSi₂ powder with a molar ratio of 3 was employed to join SiC ceramics at different joining temperatures, and the shear strength of the joint was positively correlated with the joining temperature. The SiC joint achieved in this study offers great potential for application in extreme environments.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196656","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}

{"title":"Simultaneously reduced thermal expansion coefficients and conductivity of SiO2–AlTaO4 oxides with the enhanced toughness","authors":"Luyang Zhang,&nbsp;Lin Chen,&nbsp;Jiankun Wang,&nbsp;Bingyan Wu,&nbsp;Jing Feng","doi":"10.1111/jace.70185","DOIUrl":"https://doi.org/10.1111/jace.70185","url":null,"abstract":"<p>Directional optimization of properties is of significant interest for various protective coatings materials. This study investigates the effects of SiO₂ doping on AlTaO₄ ceramics as environmental barrier coatings (EBCs), and the changes in crystal structure and comprehensive properties are thoroughly investigated. The <i>x</i> mol% SiO₂–AlTaO₄ (SATO, <i>x</i> = 0, 3, 6, 9, 12, 15) ceramics are fabricated via a solid-state sintering process, and their structures, as well as thermo-mechanical properties, are systematically analyzed. The results reveal that SiO₂ doping introduces point defects and lattice distortions, which significantly reduce the thermal conductivity by 44% at 900°C, and effectively suppresses the increase in thermal conductivity at elevated temperatures. Furthermore, the fracture toughness is improved from 3.01 to 3.38 MPa·m^1/2, demonstrating superior mechanical properties compared with other EBC materials. The thermal expansion coefficients (TECs) are reduced to 5.71 × 10⁻⁶ K⁻¹ at 1200°C, which match with those of SiC ceramic matrix composites (TECs = 5.50 × 10⁻⁶ K⁻¹). These findings highlight that SATO ceramics are promising candidates as EBC materials, and SiO₂ doping can further advance its high-temperature applications.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196630","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}

{"title":"Ultra-uniform nanocrystalline hydroxyapatite ceramics via two-step sintering and quenching","authors":"Tinghan He,&nbsp;Ruitao Hu,&nbsp;Hao Shi,&nbsp;Qipeng Li,&nbsp;Yuyi Wang,&nbsp;Cong Feng,&nbsp;Yumei Xiao,&nbsp;Ye Wang,&nbsp;Xiangfeng Li,&nbsp;Xiangdong Zhu,&nbsp;Xingdong Zhang","doi":"10.1111/jace.70155","DOIUrl":"https://doi.org/10.1111/jace.70155","url":null,"abstract":"<p>The enhancement of the mechanical properties of hydroxyapatite (HA) bioceramics constitutes a significant research focus in the biomedical field. The present study is dedicated to the preparation of ultra-uniform nanocrystalline HA bioceramics and their influence on the mechanical properties and biological performances. First, HA powder with a uniform dispersion was fabricated through a sequential process encompassing low-temperature pre-sintering, ball milling, and gradient centrifugation. Subsequently, the green body underwent the two-step sintering and the quenching process to enhance the density and mechanical strength. The nanoceramics displayed excellent hydrophilicity and increased roughness. The nanoindentation tests revealed that the nanoceramics did not undergo any elastic-plastic deformation, and there was no indentation size effect phenomenon. In vitro biological performances suggested that the nanoceramics have the potential to facilitate osteogenic differentiation of bone marrow mesenchymal stem cells. Therefore, it can be concluded that the construction of ultra-uniform nanocrystalline is an effective approach to improve the mechanical and biological properties of HA bioceramics.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196622","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}

{"title":"Ab initio prediction for the thermal properties of the Al- and Si-containing MAB phases","authors":"Hang Yin,&nbsp;Xinxin Qi,&nbsp;Kebin Qin,&nbsp;Yana Wang,&nbsp;Jian Jiao,&nbsp;Xiaodong He,&nbsp;Guangping Song,&nbsp;Yongting Zheng,&nbsp;Yuelei Bai","doi":"10.1111/jace.70184","DOIUrl":"https://doi.org/10.1111/jace.70184","url":null,"abstract":"<p>This study employs first-principles calculations to predict and analyze the heat capacity (<i>c_p</i>) and thermal expansion coefficient (TEC) of 29 Al- and Si-containing stable MAB phases in the framework of quasi-harmonic approximation including the contributions from electronic excitation and magnetism, covering temperature ranges up to 1500 K, consistent with the present and previous experimental ones available. Generally, electronic excitation slightly increases <i>c_p</i> above 300 K, while the magnetic contribution becomes significant near the Curie temperature (<i>T</i>_C), with a peak that increases with higher <i>T</i>_C and magnetic moments. The Sicontaining MAB phases generally possess higher <i>c_p</i>, which can be explained by Kopp's law, and lower TEC due to stronger chemical bonding. Similar to <i>c_p</i>, TEC is affected by the valence electron concentration (VEC) and electronic shell number of transition metals. Notably, the TEC of magnetic MAB phases exhibits abrupt changes near <i>T</i>_C, while Cr₄AlB₄ shows an abnormally low TEC. Furthermore, these MAB phases have relatively high Debye temperature (<i>θ</i>_D), reflecting their strong bond stiffness, which decreases with increasing VEC. The Grüneisen parameter (<i>γ</i>) suggests these MAB phases exhibit low lattice anharmonicity, similar with MAX phases.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"108 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145196631","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}