Open Ceramics最新文献_第3页

Synthesis of different morphologies of ZnO using different types of organic modifiers for the enhancement of catalytic activity 采用不同类型的有机改性剂合成不同形貌的ZnO以增强催化活性

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-19 DOI: 10.1016/j.oceram.2025.100901

Md. Atikur Rahman , Tasnimul Quader Tazim , Samiur Rahman , Md. Tanvir Hossain , Muhammad Shahriar Bashar , Dipa Islam , Samina Ahmed , Md. Sahadat Hossain

This study investigates the effect of different organic modifiers, such as urea, ethylene glycol, a urea–ethylene glycol mixture, citric acid, and ammonium hydroxide, on the morphology and characteristics of ZnO nanoparticles synthesized via the hydrothermal method. Structural and optical characterizations were conducted utilizing XRD, FTIR, FESEM, and UV–Vis spectroscopy, demonstrating that the incorporation of these modifiers not only regulated particle size and morphology but also modified crystallinity and associated crystallographic attributes. Different morphologies such as, nanosheets (thickness ∼110 nm) with urea, spherical nanoparticles (∼90 nm) with ethylene glycol, nanosheets with surface imperfections (∼41 nm) with urea-ethylene glycol mixture, flower-like structures with citric acid, and nanorods (∼640 nm) with ammonium hydroxide, were produced. The crystallite sizes determined using the Scherrer equation range between 21.38 nm to 47.17 nm. The photocatalytic activity of the modified ZnO nanoparticles, evaluated from their degradation percentages, ranged from a minimum of 58.92% to a maximum of 94.80%. The findings emphasize the importance of organic modifiers in modifying the morphology, crystallinity, and photocatalytic effectiveness of ZnO nanoparticles, providing useful insights for creating new photocatalysts with excellent performance.

本研究考察了尿素、乙二醇、尿素-乙二醇混合物、柠檬酸和氢氧化铵等不同有机改性剂对水热法制备ZnO纳米粒子形貌和性能的影响。利用XRD， FTIR， FESEM和UV-Vis光谱进行了结构和光学表征，表明这些改性剂的加入不仅可以调节颗粒大小和形貌，还可以改变结晶度和相关的晶体学属性。不同的形貌，如尿素纳米片（厚度~ 110 nm），乙二醇球形纳米颗粒（~ 90 nm），尿素-乙二醇混合物的表面缺陷纳米片（~ 41 nm），柠檬酸的花状结构和氢氧化铵的纳米棒（~ 640 nm），生产出来。利用Scherrer方程确定的晶体尺寸范围在21.38 ~ 47.17 nm之间。改性ZnO纳米粒子的光催化活性从最小的58.92%到最大的94.80%不等。该研究结果强调了有机改性剂在改变ZnO纳米颗粒的形貌、结晶度和光催化效能方面的重要性，为开发具有优异性能的新型光催化剂提供了有用的见解。

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引用次数: 0

Strategies for optimized microstructure evolution during sintering 烧结过程微观结构演化优化策略

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-17 DOI: 10.1016/j.oceram.2025.100900

Friedrich Raether, Gerhard Seifert

A novel integrated microstructure model on sintering (IMS) was recently introduced. It deals with solid state sintering processes and includes grain boundary and surface diffusion as well as grain growth. To obtain a realistic simulation, the model combines four established approaches: 1. analytical sintering equations, 2. an ideal sintering model for interface energy minimization, 3. a Monte Carlo model for atomic diffusion processes and 4. a model for particle rearrangement. Compared to a previous version the IMS algorithm has been significantly improved and extended. Among other things, grain growth can now be simulated under realistic conditions and particle rotations are considered. The model is presented in detail. Simulation results allow conclusions on practical strategies to improve homogeneity and reduce grain growth during sintering.

介绍了一种新的烧结综合微观结构模型（IMS）。它处理固态烧结过程，包括晶界和表面扩散以及晶粒生长。为了获得真实的仿真，该模型结合了四种已建立的方法：1。解析烧结方程，2。界面能量最小化的理想烧结模型；3 .原子扩散过程的蒙特卡罗模型；粒子重排模型。与以前的版本相比，IMS算法得到了显著的改进和扩展。除其他外，现在可以在现实条件下模拟晶粒生长，并考虑颗粒旋转。详细介绍了该模型。模拟结果得出了改善烧结均匀性和减少晶粒生长的实用策略。

引用次数: 0

UV-assisted drop casting of photocurable ceramic suspensions: The role of venting and organic additives in dense zirconia beads manufacturing 光固化陶瓷悬浮液的紫外辅助滴铸：排气和有机添加剂在致密氧化锆珠制造中的作用

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-17 DOI: 10.1016/j.oceram.2025.100899

Blanka Seredynska, Karolina Korycka, Radoslaw Zurowski, Pawel Falkowski

UV-assisted drop casting is an effective technique for shaping ceramic beads; however, venting ceramic suspensions remains a critical factor in achieving well-densified structures. This study investigates optimal venting strategies for manufacturing zirconia beads. Four systems were evaluated, differing in the presence of an anti-foaming agent and additional vacuum venting. The viscosity of the suspensions was studied, and then ceramic beads were obtained by the UV-assisted drop casting method. The sintered beads were then analyzed for their sphericity, size distribution, Vickers hardness, fracture toughness and cross-sectional porosity. In addition, the microstructure of the series that was found to be the best was analyzed in detail. As a result of the study, a mixing and venting procedure was selected that minimizes defects and produces zirconia beads with good mechanical properties and uniform morphology.

紫外辅助滴铸是一种有效的陶瓷珠形成型技术；然而，排气陶瓷悬浮液仍然是实现良好致密结构的关键因素。本研究探讨了制造氧化锆珠的最佳排气策略。四种系统进行了评估，不同的是，存在消泡剂和额外的真空排气。对悬浮液的粘度进行了研究，然后采用紫外辅助滴铸法制备了陶瓷微珠。然后对烧结球的球度、尺寸分布、维氏硬度、断裂韧性和截面孔隙率进行了分析。此外，还对优选的系列进行了详细的微观组织分析。作为研究的结果，选择了混合和排气工艺，以最大限度地减少缺陷，并生产出具有良好力学性能和均匀形貌的氧化锆珠。

引用次数: 0

A bone-like structure of alginate-hydroxyapatite 3D printed by laser-induced forward transfer 用激光诱导正向转移3D打印海藻酸羟基磷灰石的骨状结构

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-17 DOI: 10.1016/j.oceram.2025.100898

M. Canillas , J. Navarro , A. Saiz , M.A. Rodríguez , M. Morales , S. Lauzurica , C. Molpeceres

Laser-Induced Forward Transfer (LIFT) is a widely used laser-based technique intended to print materials without modifying their properties. One of the main advantages of this transfer technique is that, properly setting the laser parameters and the structure of the donor substrate, materials with different rheology and even physical state can be printed, ranging from low viscosity newtonian fluids to solid state materials. On the other hand, Blister-Assisted Laser-Induced Forward Transfer (BA-LIFT) is a variant of the standard LIFT, wherein a polyimide layer is interposed between the donor substrate and the material to be printed. This configuration eliminates direct laser-material interaction, thereby mitigating photothermal degradation and, in particular in the case of bioinks containing living cells, preserving cell viability. In addition, as nozzle free technologies both avoid clogging problems when ceramic particles are added in the formulation. In this study, we optimized key parameters for the fabrication of three-dimensional scaffolds composed of alginate and tri-calcium phosphate (ALG–TCP) composites using BA-LIFT. The aim was to engineer bone-mimetic constructs capable of acting as extracellular matrices that support cell adhesion and proliferation. The formulation and curing process were tailored and studied to enhance crosslinking efficiency, improving overall biocompatibility while preserving the mechanical stability in the final structure, and minimizing aggressive conditions during the curing process, allowing good cell viability in case of use the formulation to design an ink within embedded living cells. This study demonstrates that a 0.1 M CaCl₂ solution is sufficient to induced effective gelation. Furthermore, the inclusion of TCP particles (20% wt) enhanced the gelation efficiency (75–95%) via surface-mediated release of Ca²⁺ ions.

激光诱导正向转移（LIFT）是一种广泛使用的基于激光的技术，旨在打印材料而不改变其特性。这种转移技术的主要优点之一是，适当设置激光参数和供体衬底的结构，可以打印从低粘度牛顿流体到固体材料等具有不同流变甚至物理状态的材料。另一方面，泡罩辅助激光诱导正向转移（BA-LIFT）是标准LIFT的一种变体，其中聚酰亚胺层被插入到供体衬底和待打印材料之间。这种结构消除了激光与材料的直接相互作用，从而减轻了光热降解，特别是在含有活细胞的生物墨水的情况下，保持了细胞的活力。此外，由于无喷嘴技术都避免堵塞问题时，陶瓷颗粒添加到配方。在本研究中，我们优化了BA-LIFT法制备海藻酸盐与磷酸三钙（ALG-TCP）复合材料三维支架的关键参数。目的是设计能够作为细胞外基质支持细胞粘附和增殖的骨模拟结构。对配方和固化工艺进行了量身定制和研究，以提高交联效率，提高整体生物相容性，同时保持最终结构的机械稳定性，并最大限度地减少固化过程中的侵蚀条件，从而在使用配方设计嵌入活细胞内的墨水时具有良好的细胞活力。本研究表明，0.1 M的氯化钙溶液足以诱导有效凝胶化。此外，TCP颗粒（20% wt）通过表面介导的Ca2+离子释放提高了凝胶效率（75-95%）。

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引用次数: 0

Effects of granite wastes addition on porcelain rheological and technological properties for design jewellery and accessories production by direct ink writing 花岗石废料添加对直接墨写工艺生产设计首饰及配件用瓷器流变性及工艺性能的影响

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-15 DOI: 10.1016/j.oceram.2025.100897

Matteo Mor, Alex Sangiorgi, Sonia Conte, Guia Guarini, Chiara Zanelli, Chiara Molinari

Additive manufacturing technologies have reshaped the fashion factory, giving to designer infinite creative possibility. Unlike traditional manufacturing methods, only the material necessary to build-up the object is employed, reducing waste production and improving sustainability. Direct Ink Writing (DIW) is the primary technique used for jewellery and accessories production, enabling the production of high-resolution ceramic products allowing to ink customization. Furthermore, wastes valorisation has become a cross-sector hot topic, to reduce raw materials costs and landfill volumes. The ceramic factory has been at the forefront for years of both resource efficiency and the circular economy. The possibility of ennobling waste in high artistic value creations is certainly a challenge of the contemporary world. The aim of this study was to investigate the possibility to produce waste based ceramic objects starting from eco-friendly inks formulation. For this purpose, two mining scraps were selected. The results obtained show an effective possibility of using waste materials. Starting from a commercial porcelain mixture, different amounts of granite waste were added (from 5 to 30 % w/w). Additionally, water and glycerol were used to optimize the formulations, and the achieved inks were rheologically characterized. Samples were shaped by DIW technology, dried and fired at 1220 °C. The obtained materials and samples were characterized by hot stage microscopy, SEM microscopy, colorimetry, XRD analysis and flexural strength to evaluate the influence of the different components on the final properties. The obtained results show an effective possibility of using waste materials for DIW inks formulation and printing.

增材制造技术重塑了时尚工厂，赋予设计师无限的创作可能性。与传统的制造方法不同，它只使用建造物体所需的材料，减少了废物的产生，提高了可持续性。直接墨水书写（DIW）是用于珠宝和配饰生产的主要技术，可以生产高分辨率的陶瓷产品，允许墨水定制。此外，废物增值已成为一个跨部门的热门话题，以减少原材料成本和填埋量。多年来，陶瓷厂一直走在资源效率和循环经济的前沿。在高艺术价值的创作中使浪费变得高贵的可能性当然是当代世界的一个挑战。本研究的目的是探讨从环保油墨配方开始生产基于废物的陶瓷物体的可能性。为此，选择了两种采矿废料。所得结果表明，利用废弃物是可行的。从商业瓷器混合物开始，加入不同数量的花岗岩废料（从5%到30% w/w）。此外，用水和甘油对配方进行优化，并对得到的油墨进行了流变学表征。样品通过DIW技术成型，干燥并在1220°C下烧制。采用热段显微镜、SEM显微镜、比色法、XRD分析和抗弯强度等方法对所得材料和样品进行表征，评价不同组分对最终性能的影响。研究结果表明，利用废旧材料制备DIW油墨和印刷是可行的。

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引用次数: 0

Simultaneous effect of cassava peels content and temperature of low cost ceramics membranes 木薯皮含量和温度对低成本陶瓷膜的同时影响

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-09 DOI: 10.1016/j.oceram.2025.100896

Ibrahim Cherif Mountapbeme , Amadou Pountouenchi , Emma Augustine Julienne Ndzana , Mouhamed Mouafon , Yacouba Mfomboum Kouotou , Saliou Njuhou , Jacques Richard Mache , Gisèle Laure Lecomte-Nana , Dayirou Njoya

In order to evaluate the joint influence of cassava peel waste and temperature on the properties of a ceramic membrane, two kaolinitic clays named EB and KG from Ebebda and Koutaba respectively, were mixed with cassava peel (CP) collected in the Bangourain locality. The raw materials were characterized by X-ray fluorescence spectroscopy, differential thermal and gravimetric analyses, particle size analysis and specific surfaces area. The substrates were sintered at 900 and 1100 °C and characterized by XRD, SEM, firing shrinkage, mass loss, water absorption, porosity, bulk density and flexural strength. The addition of cassava peel between 4 and 14 % contributes to an increase in shrinkage, mass loss, water absorption and porosity at all firing temperatures. This increase reduces flexural strength and bulk density. At 900 °C, the membranes contain quartz, hematite and anatase as crystalline phases, while at 1100 °C, mullite, quartz, hematite and rutile are observed. Cassava peel has no influence on the formation of these crystalline phases, while temperature plays a key role in their formation and crystallinity. The addition of CP powder has a significant influence on membrane microstructure.

为了研究木薯皮废弃物和温度对陶瓷膜性能的共同影响，将分别来自Ebebda和Koutaba的两种高岭石粘土EB和KG与Bangourain地区收集的木薯皮（CP）混合。采用x射线荧光光谱、差热分析和重量分析、粒度分析和比表面积分析对原料进行了表征。采用XRD、SEM、烧成收缩率、质量损失率、吸水率、孔隙率、容重、抗弯强度等指标对基体进行了表征。在所有烧制温度下，木薯皮添加量在4%到14%之间有助于增加收缩率、质量损失、吸水率和孔隙率。这种增加降低了弯曲强度和体积密度。在900℃时，膜的晶相为石英、赤铁矿和锐钛矿，而在1100℃时，膜的晶相为莫来石、石英、赤铁矿和金红石。木薯皮对这些结晶相的形成没有影响，而温度对它们的形成和结晶度起着关键作用。CP粉的加入对膜的微观结构有显著的影响。

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引用次数: 0

Microstructural and sorption properties evolution on leached geopolymers for strontium decontamination 浸出地聚合物对锶净化的微观结构和吸附特性演变

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-06 DOI: 10.1016/j.oceram.2025.100895

Alexis Varon , Alban Gossard , Yves Barré , Yannick Coppel , Arnaud Poulesquen

Geopolymers are promising materials to be used as strontium adsorbent in fixed-bed processes for nuclear wastewater decontamination. Nevertheless, geopolymer formulation parameters – SiO₂/M

_{2}

O, H

_{2}

O/M

_{2}

O molar ratios – influence microstructure and strontium sorption property evolution under water leaching. Increasing the SiO₂/M

_{2}

O ratio increases the geopolymer’s compressive strength (16 MPa to 35 MPa) and reduces silicon leaching in water (1.31 mmol.g⁻¹ to 0.26 mmol.g⁻¹). This resistance to leaching results from a silicon-richer structure, reinforcing hydrolysis resistance. An increase in H

_{2}

O/M

_{2}

O ratio reduces the material’s strength (59 MPa to 28 MPa), and increases leaching due to greater porosity. Then, water leaching lowers sorption properties of the geopolymers by releasing Al

^{I V}

, which are exchange sites for cations. Nonetheless, the composition with the lowest Al

^{I V}

concentration achieved the highest distribution coefficient (K

_{D}

) and fastest kinetics. This highlights the critical role of the silicon environment for optimal cation trapping, outmatch the total concentration of Al

^{I V}

sites.

地聚合物是一种很有前途的锶吸附剂，可用于核废水的固定床净化。然而，地聚合物配方参数- SiO2/M2O， H2O/M2O摩尔比-影响水浸下的微观结构和锶吸附性能演变。提高SiO2/M2O比可提高地聚合物的抗压强度（16 MPa ~ 35 MPa），降低硅在水中的浸出（1.31 mmol）。G−1 ~ 0.26 mmol.g−1)。这种抗浸出性来自于富含硅的结构，增强了抗水解性。H2O/M2O比的增加降低了材料的强度（59 MPa至28 MPa），并且由于孔隙率的增加而增加了浸出。然后，水浸通过释放AlIV降低地聚合物的吸附性能，AlIV是阳离子的交换位点。然而，最低AlIV浓度的组合物具有最高的分配系数（KD）和最快的动力学。这突出了硅环境对最佳阳离子捕获的关键作用，超过了AlIV位点的总浓度。

{"title":"Microstructural and sorption properties evolution on leached geopolymers for strontium decontamination","authors":"Alexis Varon , Alban Gossard , Yves Barré , Yannick Coppel , Arnaud Poulesquen","doi":"10.1016/j.oceram.2025.100895","DOIUrl":"10.1016/j.oceram.2025.100895","url":null,"abstract":"<div><div>Geopolymers are promising materials to be used as strontium adsorbent in fixed-bed processes for nuclear wastewater decontamination. Nevertheless, geopolymer formulation parameters – SiO<sub>2</sub>/M<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O, H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O/M<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O molar ratios – influence microstructure and strontium sorption property evolution under water leaching. Increasing the SiO<sub>2</sub>/M<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O ratio increases the geopolymer’s compressive strength (16 MPa to 35 MPa) and reduces silicon leaching in water (1.31 mmol.g<sup>−1</sup> to 0.26 mmol.g<sup>−1</sup>). This resistance to leaching results from a silicon-richer structure, reinforcing hydrolysis resistance. An increase in H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O/M<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O ratio reduces the material’s strength (59 MPa to 28 MPa), and increases leaching due to greater porosity. Then, water leaching lowers sorption properties of the geopolymers by releasing Al<span><math><msup><mrow></mrow><mrow><mi>I</mi><mi>V</mi></mrow></msup></math></span>, which are exchange sites for cations. Nonetheless, the composition with the lowest Al<span><math><msup><mrow></mrow><mrow><mi>I</mi><mi>V</mi></mrow></msup></math></span> concentration achieved the highest distribution coefficient (K<span><math><msub><mrow></mrow><mrow><mi>D</mi></mrow></msub></math></span>) and fastest kinetics. This highlights the critical role of the silicon environment for optimal cation trapping, outmatch the total concentration of Al<span><math><msup><mrow></mrow><mrow><mi>I</mi><mi>V</mi></mrow></msup></math></span> sites.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"25 ","pages":"Article 100895"},"PeriodicalIF":2.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of aggregate particle packing on the mechanical and microstructural properties of iron-rich laterite-based geopolymer concretes 骨料颗粒充填对富铁红土基地聚合物混凝土力学和微观结构性能的影响

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-06 DOI: 10.1016/j.oceram.2025.100893

Rodrigue Cyriaque KAZE , Joseph MARAE DJOUDA , Benjamin Igor DJON LI NDJOCK , Abdolhossein NAGHIZADEH

This study investigated the effect of waste granite aggregate size on the fresh and hardened properties of high-performance concretes produced from iron-rich laterite calcined at 650°C. Three aggregate gradations of F1 (0-10 mm), F2 (0-6.5 mm), and F3 (0-5 mm), were incorporated into laterite-based geopolymer concretes and compared with Portland cement concretes produced under identical mix proportions. The activator-to-binder in geopolymer mixtures and water-to-cement ratio in Portland cement mixtures were fixed at 0.5, while the aggregate-to-binder ratio was kept constant at 2.95, regardless of the binder system. Fresh properties showed a moderate increase in slump when coarse fractions were excluded, rising from 15 to 18 mm in geopolymer mixtures and from 25 to 40 mm in Portland cement mixtures. Hardened concrete property evaluation revealed that mixtures made using F1 aggregates achieved the highest 28-day compressive strength values of 52.2 MPa for geopolymer and 48.1 MPa for Portland cement systems, along with lower porosity (10-11 %) and reduced water absorption (4.3-4.8 %). Conversely, mixes with finer F2 and F3 aggregates exhibited reduced strengths (34-45 MPa), higher porosity (14-16 %), and greater water absorption (6.5-7.2 %), confirming the detrimental effect of insufficient particle packing. Bulk density values ranged from 2230-2260 kg/m³ for mixtures containing F1 aggregate, which were higher than those of 2170 and 2200 kg/m³ for F2 and F3, respectively. Oven curing of geopolymer concretes at 60°C for 24 hours led to significant strength losses (20.3-26.6 MPa), due to rapid moisture loss and incomplete geopolymerization. Overall, the results highlight that particle size distribution plays a decisive role in optimising concrete performance, with F1 aggregates providing the most favourable balance of workability, density, and strength. The study further demonstrates the potential of thermally activated iron-rich laterite, an abundant but underutilised resource in tropical regions, combined with waste granite aggregates to produce sustainable concretes with properties comparable to Portland cement systems.

研究了废花岗岩骨料粒径对富铁红土650℃煅烧制备的高性能混凝土新鲜性能和硬化性能的影响。将F1 （0-10 mm）、F2 （0-6.5 mm）和F3 （0-5 mm）三种骨料级配掺入红土基地聚合物混凝土中，并与相同配合比下生产的波特兰水泥混凝土进行比较。无论采用何种粘结剂体系，地聚合物混合料的活化剂与粘结剂、硅酸盐水泥混合料的水灰比均固定为0.5，而骨料与粘结剂的比均保持恒定为2.95。当排除粗馏分时，新鲜性能显示出适度的坍落度增加，在地聚合物混合物中从15到18 mm增加，在波特兰水泥混合物中从25到40 mm增加。硬化混凝土性能评估显示，使用F1骨料制成的混合物达到了最高的28天抗压强度值，地聚合物为52.2 MPa，波特兰水泥体系为48.1 MPa，同时孔隙率（10- 11%）和吸水率（4.3- 4.8%）也降低了。相反，F2和F3团聚体较细的混合料强度降低（34-45 MPa），孔隙率提高（14- 16%），吸水率提高（6.5- 7.2%），证实了颗粒堆积不足的不利影响。F1骨料混合物的容重值为2230 ~ 2260 kg/m³，分别高于F2和F3的2170和2200 kg/m³。地聚合物混凝土在60°C下进行24小时的烘箱养护，由于水分流失迅速和地聚合物不完全，导致强度损失显著（20.3-26.6 MPa）。总体而言，结果强调粒径分布在优化混凝土性能方面起着决定性作用，F1骨料在和易性、密度和强度方面提供了最有利的平衡。该研究进一步证明了热活化富铁红土的潜力，这是热带地区丰富但未充分利用的资源，与废花岗岩骨料相结合，可以生产出具有与波特兰水泥系统相当性能的可持续混凝土。

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引用次数: 0

Sintering temperature dependence on microstructure and electrical properties of Co2.38Mn1.62Fe1.6Zn0.4O8 ceramics for NTC thermistors 烧结温度对Co2.38Mn1.62Fe1.6Zn0.4O8 NTC热敏电阻显微结构和电性能的影响

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-12-06 DOI: 10.1016/j.oceram.2025.100894

Jinghao Rong, Tingqing Cai, Haichao Li, Shuai Wang, Jiayao Zhang, LiangKui Peng, Shizhao Liu

Co–Mn–Fe–Zn–O-based ceramics are important negative temperature coefficient (NTC) materials. To clarify the processing-property relationship, Co₂.₃₈Mn₁.₆₂Fe₁.₆Zn₀.₄O₈ ceramics were prepared via the solid-state method, and the effects of sintering temperature (1100–1300°C) on their microstructure, electrical properties, and aging behavior were systematically investigated. XRD and SEM analyses revealed that higher temperatures promoted grain growth and densification, with the average grain size increasing from 1.6 μm to 5.3 μm. The room-temperature resistivity (ρ₂₅) exhibited a non-monotonic trend, initially increasing from 3327 Ω·cm at 1100°C to a maximum of 4287 Ω·cm at 1250°C, then decreasing to 3020 Ω·cm at 1300°C. XPS analysis indicated that the Mn³⁺/Mn⁴⁺ ratio decreased monotonically from 99.5% to 65.4% with increasing sintering temperature. This suggests that the resistivity evolution is governed by a transition in the dominant mechanism: small polaron hopping between Mn³⁺ and Mn⁴⁺ ions at lower temperatures (≤1250°C), and grain boundary scattering due to significant grain growth at higher temperatures (≥1250°C). Furthermore, all samples demonstrated excellent aging stability with a resistance drift (ΔR/R) below 0.20% over 800 hours, with the sample sintered at 1250°C achieving the optimal combination of high resistivity (4287 Ω·cm) and minimal drift (0.16%), attributable to its dense microstructure and balanced cation valence. This work provides valuable insights for optimizing the sintering process of NTC ceramics to achieve superior electrical performance and long-term stability.

co - mn - fe - zn基陶瓷是一种重要的负温度系数材料。为明确加工性质关系，Co₂.₃₈Mn₁.₆Fe₁.₆Zn₀。采用固相法制备了₄O₈陶瓷，系统研究了烧结温度（1100 ~ 1300℃）对其微观结构、电学性能和时效性能的影响。XRD和SEM分析表明，高温促进了晶粒的生长和致密化，平均晶粒尺寸从1.6 μm增加到5.3 μm。室温电阻率（ρ₂₅）呈现非单调趋势，最初从1100℃时的3327 Ω·cm增加到1250℃时的最大值4287 Ω·cm，然后在1300℃时下降到3020 Ω·cm。XPS分析表明，随着烧结温度的升高，Mn³+ /Mn⁴+的比值从99.5%单调下降到65.4%。这表明电阻率的演化受主导机制的转变支配：在较低温度（≤1250°C）下，Mn³+和Mn⁴+离子之间存在较小的极化子跳变，在较高温度（≥1250°C）下，晶粒生长导致晶界散射。此外，所有样品在800小时内均表现出优异的时效稳定性，电阻漂移（ΔR/R）低于0.20%，其中1250℃烧结的样品由于其致密的微观结构和平衡的阳离子价，实现了高电阻率（4287 Ω·cm）和最小漂移（0.16%）的最佳组合。这项工作为优化NTC陶瓷的烧结工艺以获得优异的电性能和长期稳定性提供了有价值的见解。

{"title":"Sintering temperature dependence on microstructure and electrical properties of Co2.38Mn1.62Fe1.6Zn0.4O8 ceramics for NTC thermistors","authors":"Jinghao Rong, Tingqing Cai, Haichao Li, Shuai Wang, Jiayao Zhang, LiangKui Peng, Shizhao Liu","doi":"10.1016/j.oceram.2025.100894","DOIUrl":"10.1016/j.oceram.2025.100894","url":null,"abstract":"<div><div>Co–Mn–Fe–Zn–O-based ceramics are important negative temperature coefficient (NTC) materials. To clarify the processing-property relationship, Co₂.₃₈Mn₁.₆₂Fe₁.₆Zn₀.₄O₈ ceramics were prepared via the solid-state method, and the effects of sintering temperature (1100–1300°C) on their microstructure, electrical properties, and aging behavior were systematically investigated. XRD and SEM analyses revealed that higher temperatures promoted grain growth and densification, with the average grain size increasing from 1.6 μm to 5.3 μm. The room-temperature resistivity (ρ₂₅) exhibited a non-monotonic trend, initially increasing from 3327 Ω·cm at 1100°C to a maximum of 4287 Ω·cm at 1250°C, then decreasing to 3020 Ω·cm at 1300°C. XPS analysis indicated that the Mn³⁺/Mn⁴⁺ ratio decreased monotonically from 99.5% to 65.4% with increasing sintering temperature. This suggests that the resistivity evolution is governed by a transition in the dominant mechanism: small polaron hopping between Mn³⁺ and Mn⁴⁺ ions at lower temperatures (≤1250°C), and grain boundary scattering due to significant grain growth at higher temperatures (≥1250°C). Furthermore, all samples demonstrated excellent aging stability with a resistance drift (ΔR/R) below 0.20% over 800 hours, with the sample sintered at 1250°C achieving the optimal combination of high resistivity (4287 Ω·cm) and minimal drift (0.16%), attributable to its dense microstructure and balanced cation valence. This work provides valuable insights for optimizing the sintering process of NTC ceramics to achieve superior electrical performance and long-term stability.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"25 ","pages":"Article 100894"},"PeriodicalIF":2.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of annealing dwell time on piezoelectric properties of KNN thin films: Phase insensitive behavior 退火时间对KNN薄膜压电性能的影响：相不敏感行为

IF 2.8 Q1 MATERIALS SCIENCE, CERAMICS

Open Ceramics

Pub Date : 2025-11-28 DOI: 10.1016/j.oceram.2025.100892

Binjie Chen , Fang-Zhou Yao , Zhongshang Dou , Wenying Fan , Dongfang Yu , Binglin Shen , Chao-Feng Wu , Qiang He , Chen Tian , Sheng Hu , Wen Gong , Ke Wang

Amorphous potassium sodium niobate (KNN) thin films were deposited onto Pt/Ti/SiO₂/Si substrates at 200 °C using magnetron sputtering. The resultant films were then annealed in an alkali metal element atmosphere formed by alkali metal carbonates. The influence of annealing dwell time on the films' properties was investigated. It was observed that while the overall crystalline phase and elemental composition of the films remained essentially unchanged, their electrical characteristics exhibited systematic variations. Microscopic analysis revealed that extending the annealing time within an optimal range facilitated the formation of ferroelectric domain structures and enhanced piezoresponse phase contrast between domains. However, prolonged annealing led to localized phase segregation, resulting in performance degradation. Our results provide useful insights into the fabrication of KNN thin films using magnetron sputtering or other thermally involved synthesis methods.

采用磁控溅射技术在Pt/Ti/SiO2/Si衬底上制备了非晶铌酸钾钠（KNN）薄膜。然后在碱金属碳酸盐形成的碱金属元素气氛中对所得薄膜进行退火。研究了退火时间对薄膜性能的影响。结果表明，虽然薄膜的整体晶相和元素组成基本保持不变，但其电特性却呈现出系统的变化。微观分析表明，在最佳范围内延长退火时间有利于铁电畴结构的形成，并增强了畴间的压响应相对比。然而，长时间退火导致局部相偏析，导致性能下降。我们的研究结果为利用磁控溅射或其他热相关合成方法制备KNN薄膜提供了有用的见解。

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引用次数: 0