Vitaly A. Tarala, Fedor F. Malyavin, Alexander A. Kravtsov, Ekaterina A. Brazhko, Oleg M. Chapura, Sergey V. Kuznetsov
Using the method of non‐reactive sintering of nanocrystalline powders, highly transparent samples of optical ceramics based on solid solutions of yttrium‐scandium aluminum garnets containing 50 at.% scandium in the dodecahedral position and doped with erbium (1 at.%) and ytterbium (0–49 at.%) cations (YSAG:Yb:Er) were produced. The influence of Yb3+ concentration on the crystal lattice parameter, density, refractive index, stability of YSAG:Yb:Er solid solutions during high‐temperature sintering, thermal conductivity, optical transmittance and absorption coefficients in the wavelength range from 200 to 1100 nm, as well as Stokes and anti‐Stokes luminescence, was determined. The revealed patterns make it possible to fine‐tune the physical and chemical characteristics of ceramics for the design of composite laser materials.
{"title":"Influence of Yb3+ content on the optical and thermophysical properties of YSAG:Yb:Er solid solutions","authors":"Vitaly A. Tarala, Fedor F. Malyavin, Alexander A. Kravtsov, Ekaterina A. Brazhko, Oleg M. Chapura, Sergey V. Kuznetsov","doi":"10.1111/jace.20077","DOIUrl":"https://doi.org/10.1111/jace.20077","url":null,"abstract":"Using the method of non‐reactive sintering of nanocrystalline powders, highly transparent samples of optical ceramics based on solid solutions of yttrium‐scandium aluminum garnets containing 50 at.% scandium in the dodecahedral position and doped with erbium (1 at.%) and ytterbium (0–49 at.%) cations (YSAG:Yb:Er) were produced. The influence of Yb<jats:sup>3+</jats:sup> concentration on the crystal lattice parameter, density, refractive index, stability of YSAG:Yb:Er solid solutions during high‐temperature sintering, thermal conductivity, optical transmittance and absorption coefficients in the wavelength range from 200 to 1100 nm, as well as Stokes and anti‐Stokes luminescence, was determined. The revealed patterns make it possible to fine‐tune the physical and chemical characteristics of ceramics for the design of composite laser materials.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198381","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}
Nickel titanate (NiTiO3) nanostructured materials have gained extensive attention in the field of lithium‐ion batteries (LIBs) due to their high theoretical capacity and low cost. However, NiTiO3 exhibits low conductivity and significant volume changes during cycling, resulting in capacity decay and poor cycling stability. Herein, we propose a feasible strategy to enhance the cycling performance of NiTiO3 nanostructures by adjusting their morphology. By manipulating the choice of solvent employed in the synthetic process, we obtain NiTiO3 microbars (NTO MBs) through self‐assembly of NiTiO3 nanoparticles (NTO NPs). When utilized as an anode material in LIBs, NTO MBs exhibit a capacity of 410 mAh g−1 after 200 cycles at 100 mA g−1, surpassing that of NTO NPs (212 mAh g−1). The improved performance of NTO MBs is attributed to their unique porous bar‐like structure, composed of numerous NPs, which provides a substantial storage space for Li+ ions owing to its larger specific surface area. Additionally, the porous structure accelerates the diffusion of Li+ ions and electron transfer. To gain a profound understanding of the enhanced performance through morphology adjustment, we conduct a comprehensive investigation on the growth mechanism of NTO MBs. This work provides valuable insights into the mechanism governing the morphology control of NTO MBs, facilitating the rational design and synthesis of tailored materials with enhanced performance for LIBs.
{"title":"Complexant‐facilitated assembly of NiTiO3 nanoparticles into microbars for high‐performance lithium‐ion battery anode","authors":"Meng Sun, Xiaoli Sheng, Zhipeng Cui, Sijie Li, Qingye Zhang, Fei Xie, Guanting Liu, Shujin Hao, Feiyu Diao, Shiduo Sun, Yiqian Wang","doi":"10.1111/jace.20068","DOIUrl":"https://doi.org/10.1111/jace.20068","url":null,"abstract":"Nickel titanate (NiTiO<jats:sub>3</jats:sub>) nanostructured materials have gained extensive attention in the field of lithium‐ion batteries (LIBs) due to their high theoretical capacity and low cost. However, NiTiO<jats:sub>3</jats:sub> exhibits low conductivity and significant volume changes during cycling, resulting in capacity decay and poor cycling stability. Herein, we propose a feasible strategy to enhance the cycling performance of NiTiO<jats:sub>3</jats:sub> nanostructures by adjusting their morphology. By manipulating the choice of solvent employed in the synthetic process, we obtain NiTiO<jats:sub>3</jats:sub> microbars (NTO MBs) through self‐assembly of NiTiO<jats:sub>3</jats:sub> nanoparticles (NTO NPs). When utilized as an anode material in LIBs, NTO MBs exhibit a capacity of 410 mAh g<jats:sup>−1</jats:sup> after 200 cycles at 100 mA g<jats:sup>−1</jats:sup>, surpassing that of NTO NPs (212 mAh g<jats:sup>−1</jats:sup>). The improved performance of NTO MBs is attributed to their unique porous bar‐like structure, composed of numerous NPs, which provides a substantial storage space for Li<jats:sup>+</jats:sup> ions owing to its larger specific surface area. Additionally, the porous structure accelerates the diffusion of Li<jats:sup>+</jats:sup> ions and electron transfer. To gain a profound understanding of the enhanced performance through morphology adjustment, we conduct a comprehensive investigation on the growth mechanism of NTO MBs. This work provides valuable insights into the mechanism governing the morphology control of NTO MBs, facilitating the rational design and synthesis of tailored materials with enhanced performance for LIBs.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198422","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}
Jiaheng Du, Weiwei Sun, Yujie Xin, Rui Tao, Xiaoxia Hu, Pan Wang, Dongshuai Hou
Using fly ash (FA) to modify magnesium phosphate cement (MPC) not only extends setting time and enhances MPC performance but also reduces costs. Currently, high‐quality FA is predominantly used, whereas the accumulation of low‐quality FA poses challenges for waste management and environmental protection. This study focuses on low‐quality FA with excessive sulfur content. Initially, X‐ray fluorescence spectroscopy was employed to select two types of FA with SO3 contents of 1.06% and 6.07%. FA replaced magnesium oxide in equal mass to prepare FA/MPC composite cementitious materials. The composite materials were studied for hydration heat, phase composition, infrared spectroscopy, mechanical properties, and microscopic morphology to explore SO3’s impact on MPC hydration processes, microstructure, and properties. The findings indicate that adding FA effectively dilutes reactants, extending setting time from 7 to 17 min and 18 min, aiding construction operations. In the FA/MPC composite cementitious materials, MPC hydration, along with FA's synergistic hydration, forms a new hydration product MgSiO3, improving material density and mechanical strength post‐hardening. Excessive SO3 in high‐sulfur FA accelerates MgO decomposition, providing ample Mg2+ for K‐struvite synthesis, promoting MPC hydration, and transforming K‐struvite from amorphous to crystalline, enhancing material strength.
使用粉煤灰（FA）改性磷酸镁水泥（MPC）不仅能延长凝结时间、提高 MPC 性能，还能降低成本。目前，主要使用高质量的粉煤灰，而低质量粉煤灰的积累给废物管理和环境保护带来了挑战。本研究主要针对硫含量过高的劣质 FA。首先，采用 X 射线荧光光谱法筛选出两种 SO3 含量分别为 1.06% 和 6.07% 的 FA。用等质量的 FA 取代氧化镁，制备 FA/MPC 复合胶凝材料。研究了复合材料的水化热、相组成、红外光谱、力学性能和微观形态，以探讨 SO3 对 MPC 水化过程、微观结构和性能的影响。研究结果表明，添加 FA 可以有效稀释反应物，将凝结时间从 7 分钟延长到 17 分钟和 18 分钟，从而有助于施工操作。在 FA/MPC 复合胶凝材料中，MPC 水化与 FA 的协同水化一起形成了一种新的水化产物 MgSiO3，提高了材料的密度和硬化后的机械强度。高硫 FA 中过量的 SO3 会加速 MgO 的分解，为 K-struvite 的合成提供充足的 Mg2+，促进 MPC 的水化，并将 K-struvite 从无定形转变为晶体，从而提高材料强度。
{"title":"Influence of high‐sulfur fly ash on the microstructure and properties of magnesium phosphate cement","authors":"Jiaheng Du, Weiwei Sun, Yujie Xin, Rui Tao, Xiaoxia Hu, Pan Wang, Dongshuai Hou","doi":"10.1111/jace.20064","DOIUrl":"https://doi.org/10.1111/jace.20064","url":null,"abstract":"Using fly ash (FA) to modify magnesium phosphate cement (MPC) not only extends setting time and enhances MPC performance but also reduces costs. Currently, high‐quality FA is predominantly used, whereas the accumulation of low‐quality FA poses challenges for waste management and environmental protection. This study focuses on low‐quality FA with excessive sulfur content. Initially, X‐ray fluorescence spectroscopy was employed to select two types of FA with SO<jats:sub>3</jats:sub> contents of 1.06% and 6.07%. FA replaced magnesium oxide in equal mass to prepare FA/MPC composite cementitious materials. The composite materials were studied for hydration heat, phase composition, infrared spectroscopy, mechanical properties, and microscopic morphology to explore SO<jats:sub>3</jats:sub>’s impact on MPC hydration processes, microstructure, and properties. The findings indicate that adding FA effectively dilutes reactants, extending setting time from 7 to 17 min and 18 min, aiding construction operations. In the FA/MPC composite cementitious materials, MPC hydration, along with FA's synergistic hydration, forms a new hydration product MgSiO<jats:sub>3</jats:sub>, improving material density and mechanical strength post‐hardening. Excessive SO<jats:sub>3</jats:sub> in high‐sulfur FA accelerates MgO decomposition, providing ample Mg<jats:sup>2+</jats:sup> for K‐struvite synthesis, promoting MPC hydration, and transforming K‐struvite from amorphous to crystalline, enhancing material strength.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198384","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}
Renato S. M. Almeida, Marcelo B. R. Rech, Jéssica Condi Mainardi, Kamen Tushtev, Kurosch Rezwan
Oxide ceramic matrix composites (Ox‐CMCs) are composed of porous matrices reinforced by dense fibers to achieve high damage tolerance. It is generally assumed that their mechanical properties are fiber dominant. However, fiber strength can also be influenced by the surrounding matrix as it can affect fiber grain growth. Fiber–matrix interactions are studied in this work regarding fiber microstructural evolution and composite strength. Minicomposites containing Nextel 610 fibers and different matrix compositions (alumina, alumina–zirconia, and mullite–alumina) are evaluated after sintering and after additional heat treatment at 1200°C for 100 h. Fiber grain growth during sintering is faster in alumina matrix and slower in mullite–alumina matrix. Scanning transmission electron microscope–energy‐dispersive X‐ray spectroscopy (STEM–EDX) measurements show that Si diffuses between fiber and matrix grain boundaries. This outward or inward diffusion of SiO2 leads to the respectively different grain growth kinetics. Grain growth inhibition in alumina–zirconia matrix is only observed after the longer heat treatment, suggesting that ZrO2 diffusion is slower than SiO2. The resultant composite strength depends not only on fiber properties, but also on matrix densification. Minicomposite with alumina–zirconia matrix showed higher strength, while mullite–alumina composites showed higher thermal stability. In summary, the properties of Ox‐CMCs can be tailored by adjusting the matrix composition with the used fibers.
{"title":"Matrix compositions and their impact on grain growth and strength of oxide ceramic composites","authors":"Renato S. M. Almeida, Marcelo B. R. Rech, Jéssica Condi Mainardi, Kamen Tushtev, Kurosch Rezwan","doi":"10.1111/jace.20069","DOIUrl":"https://doi.org/10.1111/jace.20069","url":null,"abstract":"Oxide ceramic matrix composites (Ox‐CMCs) are composed of porous matrices reinforced by dense fibers to achieve high damage tolerance. It is generally assumed that their mechanical properties are fiber dominant. However, fiber strength can also be influenced by the surrounding matrix as it can affect fiber grain growth. Fiber–matrix interactions are studied in this work regarding fiber microstructural evolution and composite strength. Minicomposites containing Nextel 610 fibers and different matrix compositions (alumina, alumina–zirconia, and mullite–alumina) are evaluated after sintering and after additional heat treatment at 1200°C for 100 h. Fiber grain growth during sintering is faster in alumina matrix and slower in mullite–alumina matrix. Scanning transmission electron microscope–energy‐dispersive X‐ray spectroscopy (STEM–EDX) measurements show that Si diffuses between fiber and matrix grain boundaries. This outward or inward diffusion of SiO<jats:sub>2</jats:sub> leads to the respectively different grain growth kinetics. Grain growth inhibition in alumina–zirconia matrix is only observed after the longer heat treatment, suggesting that ZrO<jats:sub>2</jats:sub> diffusion is slower than SiO<jats:sub>2</jats:sub>. The resultant composite strength depends not only on fiber properties, but also on matrix densification. Minicomposite with alumina–zirconia matrix showed higher strength, while mullite–alumina composites showed higher thermal stability. In summary, the properties of Ox‐CMCs can be tailored by adjusting the matrix composition with the used fibers.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198382","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}
Weijie Zhu, Weichao Wang, Xin Geng, Yueting Liu, Yao Ji, Binfeng Liang
Phosphate glasses have garnered significant attention as host materials for various laser applications due to their high rare‐earth ion solubility, large stimulated emission cross‐section, and low nonlinear refractive index. Modification of phosphate glass composition is feasible through poly‐anion substitution, leading to poly‐anionic glasses with unique properties. This study explores the glass‐forming regions (GFRs) of AlF3‐R2SO4‐M(PO3)2‐based poly‐anionic fluoro‐sulfo‐phosphate (R/M‐FSP) glasses, a promising class of ionic glasses. Theoretical GFRs are predicted using a thermodynamic approach and then validated through a few experiments. The experimental GFRs range from K/Ba‐FSP > Na/Ba‐FSP > Li/Ba‐FSP > K/Sr‐FSP > Na/Sr‐FSP > Li/Sr‐FSP, with wider areas observed under lower cation field strength. Notably, the K/Ba‐FSP glass system exhibits high anti‐crystallization stability (approximately 140°C) and a low nonlinear refractive index (1.43 × 10–13–1.83 × 10–13 esu), advantageous for high‐power laser operations. Furthermore, a comparative study among K/Ba‐FSP glasses elucidates the general principles of manipulating glass structure and physical properties through compositional variation.
{"title":"Prediction of glass‐forming regions in AlF3‐M(PO3)2‐R2SO4‐based poly‐anionic fluoro‐sulfo‐phosphate glasses","authors":"Weijie Zhu, Weichao Wang, Xin Geng, Yueting Liu, Yao Ji, Binfeng Liang","doi":"10.1111/jace.20055","DOIUrl":"https://doi.org/10.1111/jace.20055","url":null,"abstract":"Phosphate glasses have garnered significant attention as host materials for various laser applications due to their high rare‐earth ion solubility, large stimulated emission cross‐section, and low nonlinear refractive index. Modification of phosphate glass composition is feasible through poly‐anion substitution, leading to poly‐anionic glasses with unique properties. This study explores the glass‐forming regions (GFRs) of AlF<jats:sub>3</jats:sub>‐R<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub>‐M(PO<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>‐based poly‐anionic fluoro‐sulfo‐phosphate (R/M‐FSP) glasses, a promising class of ionic glasses. Theoretical GFRs are predicted using a thermodynamic approach and then validated through a few experiments. The experimental GFRs range from K/Ba‐FSP > Na/Ba‐FSP > Li/Ba‐FSP > K/Sr‐FSP > Na/Sr‐FSP > Li/Sr‐FSP, with wider areas observed under lower cation field strength. Notably, the K/Ba‐FSP glass system exhibits high anti‐crystallization stability (approximately 140°C) and a low nonlinear refractive index (1.43 × 10<jats:sup>–13</jats:sup>–1.83 × 10<jats:sup>–13</jats:sup> esu), advantageous for high‐power laser operations. Furthermore, a comparative study among K/Ba‐FSP glasses elucidates the general principles of manipulating glass structure and physical properties through compositional variation.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198415","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}
Yang Chen, Junyu Chen, Yuxuan Luo, Qiang Wang, Hai Guo
Fluorescence intensity ratio (FIR) thermometry has been regarded as new optical thermometry because of its faster response, higher sensitivity, and accuracy. However, improving the sensitivity is still a challenge. Here, Ba2LuNbO6:Er3+,Yb3+ up‐conversion specimens were synthesized, characterized, and designed for dual‐mode thermometry based on FIR. The 2H11/2/4S3/2 thermally coupled energy levels (TCELs) and 2H11/2/4F9/2 non‐TCELs (NTCELs) of Er3+ were selected as two FIR modes for optical thermometry. The energy gap of 2H11/2/4S3/2 TCELs of Er3+ in Ba2LuNbO6:Er3+,Yb3+ phosphors was confirmed as 977 cm−1. Therefore, the maximal relative sensitivity (Sr) of FIR based on TCELs is 1.53% K−1 @ 303 K. For FIR based on NTCELs, a higher maximal Sr value of 1.81% K−1 @ 303 K is obtained, which surpasses other Er3+‐doped up‐conversion specimens. In addition, the phosphors exhibit excellent thermal fatigue resistance and temperature resolution. Results suggest that Ba2LuNbO6:Er3+,Yb3+ specimens might be applied in the temperature sensing field.
{"title":"Ba2LuNbO6:Er3+,Yb3+ up‐conversion phosphors for dual‐mode thermometry based on fluorescence intensity ratio","authors":"Yang Chen, Junyu Chen, Yuxuan Luo, Qiang Wang, Hai Guo","doi":"10.1111/jace.20058","DOIUrl":"https://doi.org/10.1111/jace.20058","url":null,"abstract":"Fluorescence intensity ratio (FIR) thermometry has been regarded as new optical thermometry because of its faster response, higher sensitivity, and accuracy. However, improving the sensitivity is still a challenge. Here, Ba<jats:sub>2</jats:sub>LuNbO<jats:sub>6</jats:sub>:Er<jats:sup>3+</jats:sup>,Yb<jats:sup>3+</jats:sup> up‐conversion specimens were synthesized, characterized, and designed for dual‐mode thermometry based on FIR. The <jats:sup>2</jats:sup>H<jats:sub>11/2</jats:sub>/<jats:sup>4</jats:sup>S<jats:sub>3/2</jats:sub> thermally coupled energy levels (TCELs) and <jats:sup>2</jats:sup>H<jats:sub>11/2</jats:sub>/<jats:sup>4</jats:sup>F<jats:sub>9/2</jats:sub> non‐TCELs (NTCELs) of Er<jats:sup>3+</jats:sup> were selected as two FIR modes for optical thermometry. The energy gap of <jats:sup>2</jats:sup>H<jats:sub>11/2</jats:sub>/<jats:sup>4</jats:sup>S<jats:sub>3/2</jats:sub> TCELs of Er<jats:sup>3+</jats:sup> in Ba<jats:sub>2</jats:sub>LuNbO<jats:sub>6</jats:sub>:Er<jats:sup>3+</jats:sup>,Yb<jats:sup>3+</jats:sup> phosphors was confirmed as 977 cm<jats:sup>−1</jats:sup>. Therefore, the maximal relative sensitivity (<jats:italic>S</jats:italic><jats:sub>r</jats:sub>) of FIR based on TCELs is 1.53% K<jats:sup>−1</jats:sup> @ 303 K. For FIR based on NTCELs, a higher maximal <jats:italic>S</jats:italic><jats:sub>r</jats:sub> value of 1.81% K<jats:sup>−1</jats:sup> @ 303 K is obtained, which surpasses other Er<jats:sup>3+</jats:sup>‐doped up‐conversion specimens. In addition, the phosphors exhibit excellent thermal fatigue resistance and temperature resolution. Results suggest that Ba<jats:sub>2</jats:sub>LuNbO<jats:sub>6</jats:sub>:Er<jats:sup>3+</jats:sup>,Yb<jats:sup>3+</jats:sup> specimens might be applied in the temperature sensing field.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198385","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":"Advances in computational ceramics and glasses","authors":"Jincheng Du, John C. Mauro, Yanchun Zhou","doi":"10.1111/jace.20067","DOIUrl":"https://doi.org/10.1111/jace.20067","url":null,"abstract":"","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198417","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}
Lorena R. Rodrigues, Gisele G. Santos, María Helena R. Acosta, Akio Koike, Shusaku Akiba, Shigeki Sawamura, Mikio Nagano, Satoshi Yoshida, Francisco C. Serbena, Edgar D. Zanotto
Transparent glass‐ceramics (GCs) are promising for applications that require both optical clarity and superior mechanical strength, such as high‐performance displays and ballistic armor. However, achieving this combination typically involves a trade‐off, as crystallization processes that enhance mechanical properties often compromise transparency. This study investigates the optimization of mechanical properties in transparent and translucent MgO‐Al2O3‐SiO2 (MAS) GCs. We examine the heat treatment conditions necessary for achieving various levels of transparency and evaluate the influence of crystal size and volume fraction on Vickers hardness, indentation crack resistance, and fracture toughness (KIc). Our findings indicate that, depending on the composition and heat treatment conditions, even nanocrystals smaller than 100 nm can diminish transparency, rendering the GCs translucent. Translucent and opaque samples exhibit superior mechanical performance due to higher crystallized fractions and larger crystals. However, specific thermal protocols were identified to produce transparent GCs (visible light transmittance > 80% for 1.5 mm thick samples) with at least a 30% increase in KIc compared to their parent glasses. This study demonstrates the feasibility of balancing transparency and mechanical strength in MAS GCs through careful optimization of processing parameters.
{"title":"Balancing transparency with enhanced mechanical properties in MgO‐Al2O3‐SiO2 glass‐ceramics","authors":"Lorena R. Rodrigues, Gisele G. Santos, María Helena R. Acosta, Akio Koike, Shusaku Akiba, Shigeki Sawamura, Mikio Nagano, Satoshi Yoshida, Francisco C. Serbena, Edgar D. Zanotto","doi":"10.1111/jace.20060","DOIUrl":"https://doi.org/10.1111/jace.20060","url":null,"abstract":"Transparent glass‐ceramics (GCs) are promising for applications that require both optical clarity and superior mechanical strength, such as high‐performance displays and ballistic armor. However, achieving this combination typically involves a trade‐off, as crystallization processes that enhance mechanical properties often compromise transparency. This study investigates the optimization of mechanical properties in transparent and translucent MgO‐Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐SiO<jats:sub>2</jats:sub> (MAS) GCs. We examine the heat treatment conditions necessary for achieving various levels of transparency and evaluate the influence of crystal size and volume fraction on Vickers hardness, indentation crack resistance, and fracture toughness (K<jats:sub>Ic</jats:sub>). Our findings indicate that, depending on the composition and heat treatment conditions, even nanocrystals smaller than 100 nm can diminish transparency, rendering the GCs translucent. Translucent and opaque samples exhibit superior mechanical performance due to higher crystallized fractions and larger crystals. However, specific thermal protocols were identified to produce transparent GCs (visible light transmittance > 80% for 1.5 mm thick samples) with at least a 30% increase in K<jats:sub>Ic</jats:sub> compared to their parent glasses. This study demonstrates the feasibility of balancing transparency and mechanical strength in MAS GCs through careful optimization of processing parameters.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198414","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}
Syed Imran Abbas Shah, Karam Jabbour, Nigarish Bano, Muhammad Yousaf Ur Rehman, Razan A. Alshgari, Muhammad Fahad Ehsan
Green and sustainable energy alternatives to replace fossil fuels are a topic of research in scientific community, thus yielding pursuit of advancing renewable energy systems with hydrogen emerging as a suitable and viable alternative. Efficient and non‐precious metal catalysts are crucial for large‐scale electrochemical water splitting yielding clean H2. Here, a novel two‐step hydrothermal synthesis approach to fabricate manganese–cobalt selenide nano‐cubes grown directly on nickel foam (NF) (MnCo2Se4/NF) is adopted. Leveraging its hierarchically structured architecture, augmented active sites, and electrochemically active surface area, MnCo2Se4/NF material demonstrates exceptional electrocatalytic performance for both water oxidation and reduction. With an overpotential of 233 mV for oxygen evolution reaction (OER) and 187 mV for hydrogen evolution reaction at a current density of 10 mA/cm2, MnCo2Se4/NF also exhibits a Tafel slope of 44 mV/dec for sluggish OER process. Notably, this nanocrystalline catalyst displays enhanced catalytic activity under alkaline conditions, accelerates water dissociation, and maintains good stability over 50 h. Outperforming state‐of‐the‐art RuO2, particularly in two‐electrode assemblies with an overpotential of 218 mV at 10 mA/cm2, this work offers a promising pathway for designing and manufacturing of innovative bifunctional electrocatalysts for efficient water splitting processes, thereby contributing to broader goal of sustainable energy production.
{"title":"Bifunctional MnCo2Se4 nano‐cubes directly grown on nickel foam for effective water oxidation","authors":"Syed Imran Abbas Shah, Karam Jabbour, Nigarish Bano, Muhammad Yousaf Ur Rehman, Razan A. Alshgari, Muhammad Fahad Ehsan","doi":"10.1111/jace.20059","DOIUrl":"https://doi.org/10.1111/jace.20059","url":null,"abstract":"Green and sustainable energy alternatives to replace fossil fuels are a topic of research in scientific community, thus yielding pursuit of advancing renewable energy systems with hydrogen emerging as a suitable and viable alternative. Efficient and non‐precious metal catalysts are crucial for large‐scale electrochemical water splitting yielding clean H<jats:sub>2</jats:sub>. Here, a novel two‐step hydrothermal synthesis approach to fabricate manganese–cobalt selenide nano‐cubes grown directly on nickel foam (NF) (MnCo<jats:sub>2</jats:sub>Se<jats:sub>4</jats:sub>/NF) is adopted. Leveraging its hierarchically structured architecture, augmented active sites, and electrochemically active surface area, MnCo<jats:sub>2</jats:sub>Se<jats:sub>4</jats:sub>/NF material demonstrates exceptional electrocatalytic performance for both water oxidation and reduction. With an overpotential of 233 mV for oxygen evolution reaction (OER) and 187 mV for hydrogen evolution reaction at a current density of 10 mA/cm<jats:sup>2</jats:sup>, MnCo<jats:sub>2</jats:sub>Se<jats:sub>4</jats:sub>/NF also exhibits a Tafel slope of 44 mV/dec for sluggish OER process. Notably, this nanocrystalline catalyst displays enhanced catalytic activity under alkaline conditions, accelerates water dissociation, and maintains good stability over 50 h. Outperforming state‐of‐the‐art RuO<jats:sub>2</jats:sub>, particularly in two‐electrode assemblies with an overpotential of 218 mV at 10 mA/cm<jats:sup>2</jats:sup>, this work offers a promising pathway for designing and manufacturing of innovative bifunctional electrocatalysts for efficient water splitting processes, thereby contributing to broader goal of sustainable energy production.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198419","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}
Lei Han, Yu Chen, Huifang Wang, Haijun Zhang, Shaowei Zhang
A combined theoretical and experimental approach was used to investigate high‐entropy carbonitride. Density functional theory (DFT) calculations suggest that the [N]/([C]+[N]) ratio in (Ti1/6Cr1/6V1/6Mo1/6Nb1/6Ta1/6)(C1−xNx) affects its lattice thermal conductivity which could be decreased by 89% by increasing the ratio from 0 to 1/2. Moreover, a robust, flame‐retardant and high‐temperature resistant (Ti1/6Cr1/6V1/6Mo1/6Nb1/6Ta1/6)(C0.64N0.36) high‐entropy carbonitride aerogel (6‐HECNA) was synthesized. It exhibited a porosity of 94.3%, a compressive strength of 0.9 MPa, and a good high‐temperature stability up to 1673 K. These properties, along with its outstanding fire‐retardancy, and low thermal conductivity (0.122 W·m−1·K−1 at 298 K), make it a promising candidate material for thermal insulation applications under harsh conditions.
采用理论与实验相结合的方法研究了高熵碳氮化物。密度泛函理论（DFT）计算表明，(Ti1/6Cr1/6V1/6Mo1/6Nb1/6Ta1/6)(C1-xNx)中的[N]/([C]+[N])比率会影响其晶格热导率，当比率从 0 增加到 1/2 时，热导率可降低 89%。此外，还合成了一种坚固、阻燃、耐高温的（Ti1/6Cr1/6V1/6Mo1/6Nb1/6Ta1/6）（C0.64N0.36）高熵碳氮化物气凝胶（6-HECNA）。6-HECNA 具有 94.3% 的孔隙率、0.9 兆帕的抗压强度和高达 1673 K 的良好高温稳定性。这些特性，加上其出色的阻燃性和低导热率（298 K 时为 0.122 W-m-1-K-1），使其有望成为在苛刻条件下应用的隔热材料。
{"title":"Six‐principal‐component high‐entropy carbonitride aerogel thermal insulator: Theoretical and experimental studies","authors":"Lei Han, Yu Chen, Huifang Wang, Haijun Zhang, Shaowei Zhang","doi":"10.1111/jace.20027","DOIUrl":"https://doi.org/10.1111/jace.20027","url":null,"abstract":"A combined theoretical and experimental approach was used to investigate high‐entropy carbonitride. Density functional theory (DFT) calculations suggest that the [N]/([C]+[N]) ratio in (Ti<jats:sub>1/6</jats:sub>Cr<jats:sub>1/6</jats:sub>V<jats:sub>1/6</jats:sub>Mo<jats:sub>1/6</jats:sub>Nb<jats:sub>1/6</jats:sub>Ta<jats:sub>1/6</jats:sub>)(C<jats:sub>1−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic>N<jats:italic><jats:sub>x</jats:sub></jats:italic>) affects its lattice thermal conductivity which could be decreased by 89% by increasing the ratio from 0 to 1/2. Moreover, a robust, flame‐retardant and high‐temperature resistant (Ti<jats:sub>1/6</jats:sub>Cr<jats:sub>1/6</jats:sub>V<jats:sub>1/6</jats:sub>Mo<jats:sub>1/6</jats:sub>Nb<jats:sub>1/6</jats:sub>Ta<jats:sub>1/6</jats:sub>)(C<jats:sub>0.64</jats:sub>N<jats:sub>0.36</jats:sub>) high‐entropy carbonitride aerogel (6‐HECNA) was synthesized. It exhibited a porosity of 94.3%, a compressive strength of 0.9 MPa, and a good high‐temperature stability up to 1673 K. These properties, along with its outstanding fire‐retardancy, and low thermal conductivity (0.122 W·m<jats:sup>−1</jats:sup>·K<jats:sup>−1</jats:sup> at 298 K), make it a promising candidate material for thermal insulation applications under harsh conditions.","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198421","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}
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