Pub Date : 2026-02-02DOI: 10.1016/j.jeurceramsoc.2026.118204
Siyuan Wang , Wei Cai , WenJin Wu , Huasong Liu , Jianwei Zheng , Liang Qiao , Yao Ying , Juan Li , Jing Yu , Naoki Wakiya , Jingwu Zheng , Shenglei Che
Cold sintering, characterized by low temperature, low energy consumption, and environmental friendliness, offers a promising route for sintering SrFe12O19. This study systematically investigates the effects of transient solvent composition, sintering temperature, and powder morphology on the densification mechanism of SrFe12O19. In the acetic acid–ethanol transient solvent system, Fe3 + ions preferentially dissolved and reacted with acetate and hydroxyl groups to form iron–carboxylate species, which facilitated particle bonding and densification. However, increased solvent concentration and cold sintering temperature cause its decomposition into Fe2O3, and gas release; trapped gas forms pores that impede densification, leading to reduced densification at higher temperatures. Meanwhile, irregular powders promote the “dissolution–precipitation” process more effectively than spherical ones. Under optimized conditions, 16 mol/L transient solvent concentration, 40 wt% addition, 250 °C sintering temperature, 1 GPa pressure, and 3 h holding time, the ball-milled powder achieved a optimal combined magnetic properties (Hcj = 5.31 kOe, Ms = 60.39 emu/g).
{"title":"Mechanistic elucidation of cold sintering behavior in SrFe12O19 ceramics: Role of transient solvent, temperature, and particle morphology","authors":"Siyuan Wang , Wei Cai , WenJin Wu , Huasong Liu , Jianwei Zheng , Liang Qiao , Yao Ying , Juan Li , Jing Yu , Naoki Wakiya , Jingwu Zheng , Shenglei Che","doi":"10.1016/j.jeurceramsoc.2026.118204","DOIUrl":"10.1016/j.jeurceramsoc.2026.118204","url":null,"abstract":"<div><div>Cold sintering, characterized by low temperature, low energy consumption, and environmental friendliness, offers a promising route for sintering SrFe<sub>12</sub>O<sub>19</sub>. This study systematically investigates the effects of transient solvent composition, sintering temperature, and powder morphology on the densification mechanism of SrFe<sub>12</sub>O<sub>19</sub>. In the acetic acid–ethanol transient solvent system, Fe<sup>3 +</sup> ions preferentially dissolved and reacted with acetate and hydroxyl groups to form iron–carboxylate species, which facilitated particle bonding and densification. However, increased solvent concentration and cold sintering temperature cause its decomposition into Fe<sub>2</sub>O<sub>3</sub>, and gas release; trapped gas forms pores that impede densification, leading to reduced densification at higher temperatures. Meanwhile, irregular powders promote the “dissolution–precipitation” process more effectively than spherical ones. Under optimized conditions, 16 mol/L transient solvent concentration, 40 wt% addition, 250 °C sintering temperature, 1 GPa pressure, and 3 h holding time, the ball-milled powder achieved a optimal combined magnetic properties (<em>H</em><sub><em>cj</em></sub> = 5.31 kOe, <em>M</em><sub><em>s</em></sub> = 60.39 emu/g).</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118204"},"PeriodicalIF":6.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-02DOI: 10.1016/j.jeurceramsoc.2026.118205
Yang Zhou , Yanling Huang , Qiumei Huang , Ning Guan , Ning Zhang , Huaicheng Xiang , Ying Tang , Liang Fang
Next-generation wireless communication demands microwave dielectric ceramics that effectively achieve ultra-low loss, a stable resonant frequency, and a low permittivity. Here we demonstrate an entropy-engineering strategy that selectively disorders the [A(2)O6] octahedral site while preserving the rigid [GaO4] tetrahedral backbone in gallium-based olivine A2GaO4. A series of CaY1–x(Nd0.25Sm0.25Eu0.25Yb0.25)xGaO4 ceramics was synthesized by solid-state reaction at 1260–1420 °C. Systematic increases in configurational entropy (ΔSconfig) and ionic-size disorder (δR) drive a reversible Pnma → Pmnb symmetry switch, suppress phase separation, and expand the lattice. At x = 0.8, the high-entropy single-phase olivine exhibits εr = 9.2 ± 0.2, Q×f = 151,025 ± 400 GHz, and τf = -39.8 ± 2.0 ppm/°C, while Vickers hardness rises to 5.79 ± 0.2 GPa. Ultra-low loss is synergistically influenced by ΔSconfig, δR, and packing fraction. A C-band dielectric resonator antenna fabricated from the x = 0.8 composition achieves 92.63 % radiation efficiency and 6.39 dBi gain, validating the entropy-design paradigm for high-frequency applications.
{"title":"Entropy-driven design of ultra-low loss olivine CaY1–x(Nd0.25Sm0.25Eu0.25Yb0.25)xGaO4 microwave dielectric ceramics for 5 G dielectric resonator antennas","authors":"Yang Zhou , Yanling Huang , Qiumei Huang , Ning Guan , Ning Zhang , Huaicheng Xiang , Ying Tang , Liang Fang","doi":"10.1016/j.jeurceramsoc.2026.118205","DOIUrl":"10.1016/j.jeurceramsoc.2026.118205","url":null,"abstract":"<div><div>Next-generation wireless communication demands microwave dielectric ceramics that effectively achieve ultra-low loss, a stable resonant frequency, and a low permittivity. Here we demonstrate an entropy-engineering strategy that selectively disorders the [A(2)O<sub>6</sub>] octahedral site while preserving the rigid [GaO<sub>4</sub>] tetrahedral backbone in gallium-based olivine A<sub>2</sub>GaO<sub>4</sub>. A series of CaY<sub>1–<em>x</em></sub>(Nd<sub>0.25</sub>Sm<sub>0.25</sub>Eu<sub>0.25</sub>Yb<sub>0.25</sub>)<sub><em>x</em></sub>GaO<sub>4</sub> ceramics was synthesized by solid-state reaction at 1260–1420 °C. Systematic increases in configurational entropy (ΔS<sub>config</sub>) and ionic-size disorder (<em>δ</em><sub>R</sub>) drive a reversible <em>Pnma</em> → <em>Pmnb</em> symmetry switch, suppress phase separation, and expand the lattice. At <em>x</em> = 0.8, the high-entropy single-phase olivine exhibits <em>ε</em><sub><em>r</em></sub> = 9.2 ± 0.2, <em>Q×f</em> = 151,025 ± 400 GHz, and <em>τ</em><sub><em>f</em></sub> = -39.8 ± 2.0 ppm/°C, while Vickers hardness rises to 5.79 ± 0.2 GPa. Ultra-low loss is synergistically influenced by ΔS<sub>config</sub>, <em>δ</em><sub>R</sub>, and packing fraction. A C-band dielectric resonator antenna fabricated from the <em>x</em> = 0.8 composition achieves 92.63 % radiation efficiency and 6.39 dBi gain, validating the entropy-design paradigm for high-frequency applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118205"},"PeriodicalIF":6.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-31DOI: 10.1016/j.jeurceramsoc.2026.118203
Yueying Yin , Zemin Liu , Diansen Li , Lei Jiang , Stepan V. Lomov , Frederik Desplentere
This study systematically investigates the evolution of bending properties and damage mechanisms of three-dimensional angle-interlock woven alumina/mullite ceramic matrix composites (3DAW Al₂O₃-CMCs) under room-temperature (RT) and various high-temperature environments. The experimental temperature range was set from RT to 1200°C. The results indicate that the bending properties of 3DAW Al₂O₃-CMCs exhibit a non-monotonic temperature dependence, initially increasing before decreasing, with optimal performance observed at 1000°C where the maximum bending strength and bending modulus reach 128 MPa and 15.20 GPa, respectively. The damage mechanism shifts with increasing temperature: from localized fiber fracture and matrix cracking, to ductile fracture characterized by matrix softening and enhanced interfacial bonding, and finally to the state of matrix degradation coupled with fiber bundles collapse.
{"title":"Effect of temperature on bending mechanical behavior of 3D angle-interlock woven Al₂O₃/mullite ceramic matrix composites","authors":"Yueying Yin , Zemin Liu , Diansen Li , Lei Jiang , Stepan V. Lomov , Frederik Desplentere","doi":"10.1016/j.jeurceramsoc.2026.118203","DOIUrl":"10.1016/j.jeurceramsoc.2026.118203","url":null,"abstract":"<div><div>This study systematically investigates the evolution of bending properties and damage mechanisms of three-dimensional angle-interlock woven alumina/mullite ceramic matrix composites (3DAW Al₂O₃-CMCs) under room-temperature (RT) and various high-temperature environments. The experimental temperature range was set from RT to 1200°C. The results indicate that the bending properties of 3DAW Al₂O₃-CMCs exhibit a non-monotonic temperature dependence, initially increasing before decreasing, with optimal performance observed at 1000°C where the maximum bending strength and bending modulus reach 128 MPa and 15.20 GPa, respectively. The damage mechanism shifts with increasing temperature: from localized fiber fracture and matrix cracking, to ductile fracture characterized by matrix softening and enhanced interfacial bonding, and finally to the state of matrix degradation coupled with fiber bundles collapse.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118203"},"PeriodicalIF":6.2,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-30DOI: 10.1016/j.jeurceramsoc.2026.118191
Yimin Ouyang , Saidi Wang , Linwei Guo , Tao Zhang , Mengdong Ma , Bin Du
Linking atomic-scale modeling with experimental processes, first-principles calculations were combined with polymer-derived ceramic (PDC) route and high-pressure sintering to design and fabricate (Ta0.25Nb0.25Hf0.25Zr0.25)C high-entropy carbides (HECs) with exceptional hardness and modulus. The calculations show that increasing applied pressure enhances the elastic constants, bulk modulus, and theoretical hardness, guiding powder densification at 6 GPa and 1600°C (HEC1) or 1800°C (HEC2). Dense bulk ceramics with relative densities of 95.19 % and 96.33 %, were obtained without phase decomposition. Compared with HEC1, HEC2 exhibits improved crystallinity, reduced porosity, and enhanced mechanical properties, including a Vickers hardness of 28.3 GPa, nanoindentation hardness of 33.2 GPa, elastic modulus of 440.7 GPa, and fracture toughness of 4.0 MPa·m1/2. These findings highlight that integrating the PDC route with high-pressure sintering facilitates the fabrication of dense, high-performance HECs, offering a promising pathway for structural applications in extreme environments.
{"title":"First-principles guided design and high-pressure sintering of polymer-derived high-entropy carbides with superior hardness and modulus","authors":"Yimin Ouyang , Saidi Wang , Linwei Guo , Tao Zhang , Mengdong Ma , Bin Du","doi":"10.1016/j.jeurceramsoc.2026.118191","DOIUrl":"10.1016/j.jeurceramsoc.2026.118191","url":null,"abstract":"<div><div>Linking atomic-scale modeling with experimental processes, first-principles calculations were combined with polymer-derived ceramic (PDC) route and high-pressure sintering to design and fabricate (Ta<sub>0.25</sub>Nb<sub>0.25</sub>Hf<sub>0.25</sub>Zr<sub>0.25</sub>)C high-entropy carbides (HECs) with exceptional hardness and modulus. The calculations show that increasing applied pressure enhances the elastic constants, bulk modulus, and theoretical hardness, guiding powder densification at 6 GPa and 1600°C (HEC1) or 1800°C (HEC2). Dense bulk ceramics with relative densities of 95.19 % and 96.33 %, were obtained without phase decomposition. Compared with HEC1, HEC2 exhibits improved crystallinity, reduced porosity, and enhanced mechanical properties, including a Vickers hardness of 28.3 GPa, nanoindentation hardness of 33.2 GPa, elastic modulus of 440.7 GPa, and fracture toughness of 4.0 MPa·m<sup>1/2</sup>. These findings highlight that integrating the PDC route with high-pressure sintering facilitates the fabrication of dense, high-performance HECs, offering a promising pathway for structural applications in extreme environments.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118191"},"PeriodicalIF":6.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-29DOI: 10.1016/j.jeurceramsoc.2026.118190
P. Khamsepour , P. Bansal , D. Guay , A.C. Tavares , B. Guerreiro , R.S. Lima , K.R. Beyerlein
Ytterbium disilicate (YbDS) environmental barrier coatings (EBCs) are deposited by atmospheric plasma spray (APS) to protect aeroengine components made of SiCfiber(f)/SiC ceramic matrix composites. During deposition, rapid solidification of molten YbDS particles upon impact creates an amorphous structure which needs to be crystallized. This study optimized crystallization heat treatment for dense (∼2 % porosity) EBCs with as-sprayed crystallinity between 10 % and 50 %. Stable ytterbium silicate phases (YbDS and Yb₂SiO₅ (YbMS)) are formed above 1200 °C, regardless of initial crystallinity. EBCs with crystallinity of 15 % produced metastable phases at 1100 °C, requiring at least 10 h to transform them into stable phases, while coatings with 50 % crystallinity formed stable phase after only 4 h. The morphology and hardness of EBCs after crystallization are shown to be comparable irrespective of the heat treatment temperature. This demonstrates that partially crystalline as-sprayed YbDS can be crystallized faster and at lower temperatures, potentially reducing production costs.
{"title":"Reducing heat treatment time and temperature for dense crystalline ytterbium disilicate environmental barrier coatings","authors":"P. Khamsepour , P. Bansal , D. Guay , A.C. Tavares , B. Guerreiro , R.S. Lima , K.R. Beyerlein","doi":"10.1016/j.jeurceramsoc.2026.118190","DOIUrl":"10.1016/j.jeurceramsoc.2026.118190","url":null,"abstract":"<div><div>Ytterbium disilicate (YbDS) environmental barrier coatings (EBCs) are deposited by atmospheric plasma spray (APS) to protect aeroengine components made of SiC<sub>fiber(f)</sub>/SiC ceramic matrix composites. During deposition, rapid solidification of molten YbDS particles upon impact creates an amorphous structure which needs to be crystallized. This study optimized crystallization heat treatment for dense (∼2 % porosity) EBCs with as-sprayed crystallinity between 10 % and 50 %. Stable ytterbium silicate phases (YbDS and Yb₂SiO₅ (YbMS)) are formed above 1200 °C, regardless of initial crystallinity. EBCs with crystallinity of 15 % produced metastable phases at 1100 °C, requiring at least 10 h to transform them into stable phases, while coatings with 50 % crystallinity formed stable phase after only 4 h. The morphology and hardness of EBCs after crystallization are shown to be comparable irrespective of the heat treatment temperature. This demonstrates that partially crystalline as-sprayed YbDS can be crystallized faster and at lower temperatures, potentially reducing production costs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118190"},"PeriodicalIF":6.2,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-29DOI: 10.1016/j.jeurceramsoc.2026.118183
M. Sayed , N.A. Ajiba , S.B. Hanna, S.M. Naga
The present study aims to fabricate porous SiC/cordierite composites using the direct foaming technique followed by a sintering process, targeting enhanced thermal shock resistance and thermal expansion behavior. For this purpose, SiC was added in varying contents (20, 40, and 60 wt%) to the prepared pure stoichiometric cordierite matrix to evaluate their effects on porosity, phase composition, microstructure, mechanical, and thermal properties of the produced composites. The results showed that the porosity of the fabricated composites increased from 55.34 % to 68.49 % with the addition of SiC. The X-ray analysis (XRD) indicated that the addition of 20–40 wt% SiC induced a transformation from hexagonal to orthorhombic cordierite, whereas a higher SiC content of 60 wt% resulted in the coexistence of both α- and β-cordierite phases. The coefficient of thermal expansion (CTE) decreased with the addition of SiC into the cordierite matrix, while the compressive strength exhibited a maximum value for the 20 wt% SiC composite with a negative coefficient of thermal expansion. The SiC/cordierite composites demonstrated significantly improved thermal shock resistance compared to pure cordierite, allowing the SiC/cordierite composites to withstand over 40 thermal cycles without failure. The results suggest that the fabricated SiC/cordierite composites are promising candidates for high-temperature applications, offering a favorable combination of thermal stability, mechanical strength, and enhanced thermal shock resistance.
{"title":"Processing of porous SiC/cordierite composites with enhanced thermal shock resistance and negative thermal expansion","authors":"M. Sayed , N.A. Ajiba , S.B. Hanna, S.M. Naga","doi":"10.1016/j.jeurceramsoc.2026.118183","DOIUrl":"10.1016/j.jeurceramsoc.2026.118183","url":null,"abstract":"<div><div>The present study aims to fabricate porous SiC/cordierite composites using the direct foaming technique followed by a sintering process, targeting enhanced thermal shock resistance and thermal expansion behavior. For this purpose, SiC was added in varying contents (20, 40, and 60 wt%) to the prepared pure stoichiometric cordierite matrix to evaluate their effects on porosity, phase composition, microstructure, mechanical, and thermal properties of the produced composites. The results showed that the porosity of the fabricated composites increased from 55.34 % to 68.49 % with the addition of SiC. The X-ray analysis (XRD) indicated that the addition of 20–40 wt% SiC induced a transformation from hexagonal to orthorhombic cordierite, whereas a higher SiC content of 60 wt% resulted in the coexistence of both α- and β-cordierite phases. The coefficient of thermal expansion (CTE) decreased with the addition of SiC into the cordierite matrix, while the compressive strength exhibited a maximum value for the 20 wt% SiC composite with a negative coefficient of thermal expansion. The SiC/cordierite composites demonstrated significantly improved thermal shock resistance compared to pure cordierite, allowing the SiC/cordierite composites to withstand over 40 thermal cycles without failure. The results suggest that the fabricated SiC/cordierite composites are promising candidates for high-temperature applications, offering a favorable combination of thermal stability, mechanical strength, and enhanced thermal shock resistance.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118183"},"PeriodicalIF":6.2,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-29DOI: 10.1016/j.jeurceramsoc.2026.118187
Xingrui Pu , Xing Cheng , Ruize Yang , Chengzhi Wei , Xinhang Chu , Xiaohong Zhu
The large grain boundary resistance restricts conductivity of LiZr2(PO4)3 (LZP) ceramic electrolyte. This work presents an effective and simple screening technique for quickly screening out appropriate sintering aids to overcome this disadvantage. Firstly, Bi2O3 (BO), Li3BO3 (LBO) and LiBF4 (LBF) were selected from fourteen candidates as sintering aids for Li0.94Zr1.94Ta0.06(PO4)3 (LZTP) electrolyte. The correlations between phase, relative density, microstructure, composition and conductivity are discussed. The total conductivity of LZTP-0.5 wt%LBO is 8.60 × 10−5 S cm−1. LZTP-2wt%BO reaches the highest conductivity of 9.24 × 10−5 S cm−1, which is approximately 1.5 times that of pure LZTP. The reason for the total conductivity enhancement is mainly attributed to the enhancement of grain boundary transport. However, compared to BO and LBO, the LBF sintering aid exhibited negative effects on conductivity. The lithium symmetrical cell equipped with LZTP-2wt%BO exhibits a long cycle stability for 900 h. This screening strategy can provide reference and inspiration for the selection of sintering aids for other LZP-based ceramic electrolytes.
较大的晶界电阻限制了lizzr2 (PO4)3 （LZP）陶瓷电解质的导电性。这项工作提出了一种有效和简单的筛选技术，可以快速筛选出合适的烧结助剂，以克服这一缺点。首先，从14种候选材料中选择Bi2O3 （BO）、Li3BO3 （LBO）和LiBF4 （LBF）作为Li0.94Zr1.94Ta0.06(PO4)3 （LZTP）电解质的助烧剂。讨论了相、相对密度、显微组织、成分和电导率之间的关系。LZTP-0.5 wt%LBO的总电导率为8.60 × 10−5 S cm−1。LZTP-2wt%BO的电导率最高，为9.24 × 10−5 S cm−1，约为纯LZTP的1.5倍。总电导率增强的主要原因是晶界输运的增强。但与BO和LBO相比，LBF助烧剂对电导率有负面影响。LZTP-2wt%BO的锂对称电池具有900 h的长周期稳定性。该筛选策略可为其他lzp基陶瓷电解质助烧剂的选择提供参考和启示。
{"title":"A simple method for selecting suitable sintering aids for LZP-based ceramic electrolytes to improve lithium-ion conductivity","authors":"Xingrui Pu , Xing Cheng , Ruize Yang , Chengzhi Wei , Xinhang Chu , Xiaohong Zhu","doi":"10.1016/j.jeurceramsoc.2026.118187","DOIUrl":"10.1016/j.jeurceramsoc.2026.118187","url":null,"abstract":"<div><div>The large grain boundary resistance restricts conductivity of LiZr<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> (LZP) ceramic electrolyte. This work presents an effective and simple screening technique for quickly screening out appropriate sintering aids to overcome this disadvantage. Firstly, Bi<sub>2</sub>O<sub>3</sub> (BO), Li<sub>3</sub>BO<sub>3</sub> (LBO) and LiBF<sub>4</sub> (LBF) were selected from fourteen candidates as sintering aids for Li<sub>0.94</sub>Zr<sub>1.94</sub>Ta<sub>0.06</sub>(PO<sub>4</sub>)<sub>3</sub> (LZTP) electrolyte. The correlations between phase, relative density, microstructure, composition and conductivity are discussed. The total conductivity of LZTP-0.5 wt%LBO is 8.60 × 10<sup>−5</sup> S cm<sup>−1</sup>. LZTP-2wt%BO reaches the highest conductivity of 9.24 × 10<sup>−5</sup> S cm<sup>−1</sup>, which is approximately 1.5 times that of pure LZTP. The reason for the total conductivity enhancement is mainly attributed to the enhancement of grain boundary transport. However, compared to BO and LBO, the LBF sintering aid exhibited negative effects on conductivity. The lithium symmetrical cell equipped with LZTP-2wt%BO exhibits a long cycle stability for 900 h. This screening strategy can provide reference and inspiration for the selection of sintering aids for other LZP-based ceramic electrolytes.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118187"},"PeriodicalIF":6.2,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-28DOI: 10.1016/j.jeurceramsoc.2026.118186
Zhennan Xu , Dongmei He , Jiaxiang Xue , Zhengmao Yang , Zhaoke Chen , Liqiang Zhang , Xiang Xiong
SiCf/SiC composite claddings have emerged as a revolutionary solution for future nuclear fuel cladding owing to their exceptional properties. However, the extreme thermal environment during service presents significant challenges to their structural integrity and performance stability. This study investigates the microstructural evolution and mechanical degradation behavior of two-layer SiCf/SiC composite claddings following heat treatment at 1200–1500℃ with holding times of 1 and 10 h. Results indicate that moderate heat treatment (≤1300℃ for 1 h) can optimize the cladding microstructure by enhancing β-SiC crystallinity and effectively relieving residual stresses within fibers and matrix. However, as the heat treatment temperature increases and the holding time extends, varying degrees of damage occur in the fibers, interfaces, and matrix of the SiCf/SiC composite cladding, except for the coating, leading to significant mechanical degradation. After heat treatment at 1500℃ for 10 h, the radial strength retention of the cladding fell below 80 %, and the axial strength retention decreased to 58.6 %.
{"title":"Effect of heat treatment on the microstructure and mechanical properties of SiCf/SiC composite cladding","authors":"Zhennan Xu , Dongmei He , Jiaxiang Xue , Zhengmao Yang , Zhaoke Chen , Liqiang Zhang , Xiang Xiong","doi":"10.1016/j.jeurceramsoc.2026.118186","DOIUrl":"10.1016/j.jeurceramsoc.2026.118186","url":null,"abstract":"<div><div>SiC<sub>f</sub>/SiC composite claddings have emerged as a revolutionary solution for future nuclear fuel cladding owing to their exceptional properties. However, the extreme thermal environment during service presents significant challenges to their structural integrity and performance stability. This study investigates the microstructural evolution and mechanical degradation behavior of two-layer SiC<sub>f</sub>/SiC composite claddings following heat treatment at 1200–1500℃ with holding times of 1 and 10 h. Results indicate that moderate heat treatment (≤1300℃ for 1 h) can optimize the cladding microstructure by enhancing β-SiC crystallinity and effectively relieving residual stresses within fibers and matrix. However, as the heat treatment temperature increases and the holding time extends, varying degrees of damage occur in the fibers, interfaces, and matrix of the SiC<sub>f</sub>/SiC composite cladding, except for the coating, leading to significant mechanical degradation. After heat treatment at 1500℃ for 10 h, the radial strength retention of the cladding fell below 80 %, and the axial strength retention decreased to 58.6 %.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118186"},"PeriodicalIF":6.2,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-27DOI: 10.1016/j.jeurceramsoc.2026.118166
Mengrui Li , Xianmeng Chen , Boon Xian Chai , Guibing Shi , M. Akbar Rhamdhani , Li Wang , Shanqing Xu
This study proposes a novel CaTiO3 (CTO) doping strategy for MnZn ferrites to co-incorporate Ca2+ and Ti4+ ions, aiming to develop low power loss magnetic materials for megahertz-range frequency applications. The effects of CaTiO3 doping on power loss, cut-off frequency, and microstructure were systematically examined. As compared with traditional CaO and TiO2 doping, CaTiO3 doping enabled more uniform dopant distribution, refined grain structure, and enhanced electrical resistivity. Among all samples, the MnZn ferrites doped with CTO achieved an 87.5 % reduction in power loss (155 mW/cm3 at 1 MHz/30 mT/25 °C) relative to the undoped reference, while maintaining excellent magnetic performance. Loss separation analysis revealed that the major contribution to this improvement was the suppression of eddy current loss (Pe), complemented by reductions in hysteresis (Ph). This work demonstrates the great potential of CaTiO3 as a cost-effective, scalable, and efficient dopant for enhancing the high-frequency performance of MnZn ferrites in next-generation power electronics.
{"title":"Introduction of Ca2+ and Ti4+ ions by a novel additive CaTiO3 for manufacturing low power loss MnZn ferrites","authors":"Mengrui Li , Xianmeng Chen , Boon Xian Chai , Guibing Shi , M. Akbar Rhamdhani , Li Wang , Shanqing Xu","doi":"10.1016/j.jeurceramsoc.2026.118166","DOIUrl":"10.1016/j.jeurceramsoc.2026.118166","url":null,"abstract":"<div><div>This study proposes a novel CaTiO<sub>3</sub> (CTO) doping strategy for MnZn ferrites to co-incorporate Ca<sup>2+</sup> and Ti<sup>4+</sup> ions, aiming to develop low power loss magnetic materials for megahertz-range frequency applications. The effects of CaTiO<sub>3</sub> doping on power loss, cut-off frequency, and microstructure were systematically examined. As compared with traditional CaO and TiO<sub>2</sub> doping, CaTiO<sub>3</sub> doping enabled more uniform dopant distribution, refined grain structure, and enhanced electrical resistivity. Among all samples, the MnZn ferrites doped with CTO achieved an 87.5 % reduction in power loss (155 mW/cm<sup>3</sup> at 1 MHz/30 mT/25 °C) relative to the undoped reference, while maintaining excellent magnetic performance. Loss separation analysis revealed that the major contribution to this improvement was the suppression of eddy current loss (<em>P</em><sub><em>e</em></sub>), complemented by reductions in hysteresis (<em>P</em><sub><em>h</em></sub>). This work demonstrates the great potential of CaTiO<sub>3</sub> as a cost-effective, scalable, and efficient dopant for enhancing the high-frequency performance of MnZn ferrites in next-generation power electronics.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118166"},"PeriodicalIF":6.2,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-27DOI: 10.1016/j.jeurceramsoc.2026.118172
Julian Fanghanel , Satoshi Yokomizo , Shuichi Funahashi , Jeffrey Shallenberger , Ke Wang , Sophie Guillemet-Fritsch , Clive A. Randall
Cold sintering using eutectic molten salts transient chemistries presents a promising low-temperature route for fabricating NiMn2O4 based NTC thermistors without the need for conventional high-temperature sintering. In this work, we explore the use of a LiCl–LiI flux to densify NiMn2O4 at just 400 °C, achieving > 95 % relative density and preserving the spinel with minor impurities that are largely erased after a brief post anneal at 850 °C. While initial electrical properties of the cold-sintered parts are influenced by a flux-mediated reduction and cation inversion segregation, we show that a mild anneal at 850 °C is sufficient to restore a more stable thermistor. Here we argue that the transient phase of LiCl–LiI drives a cation-Frenkel–dominated reduction during the densification: transient dissolution/precipitation and halide redox promote formation of metal interstitials (Nii,Mni) paired with cation vacancies on the normal sublattices, with a valence shifts (Mn4+→Mn3+). We also report that, in the absence of annealing, these samples undergo a negative aging with a decrease in resistance over time, further supporting the role of the flux modifying the oxidation state and site occupancy. These results demonstrate that cold sintering, when paired with strategic annealing, can produce high thermistor performance with a thermally stable NTC ceramics at a fraction of the processing energy and temperature, with tunable electrical properties driven by the molten salt flux chemistry.
{"title":"Cold-sintered NiMn2O4 thermistors: An electrical aging and recovery study","authors":"Julian Fanghanel , Satoshi Yokomizo , Shuichi Funahashi , Jeffrey Shallenberger , Ke Wang , Sophie Guillemet-Fritsch , Clive A. Randall","doi":"10.1016/j.jeurceramsoc.2026.118172","DOIUrl":"10.1016/j.jeurceramsoc.2026.118172","url":null,"abstract":"<div><div>Cold sintering using eutectic molten salts transient chemistries presents a promising low-temperature route for fabricating NiMn<sub>2</sub>O<sub>4</sub> based NTC thermistors without the need for conventional high-temperature sintering. In this work, we explore the use of a LiCl–LiI flux to densify NiMn<sub>2</sub>O<sub>4</sub> at just 400 °C, achieving > 95 % relative density and preserving the spinel with minor impurities that are largely erased after a brief post anneal at 850 °C. While initial electrical properties of the cold-sintered parts are influenced by a flux-mediated reduction and cation inversion segregation, we show that a mild anneal at 850 °C is sufficient to restore a more stable thermistor. Here we argue that the transient phase of LiCl–LiI drives a cation-Frenkel–dominated reduction during the densification: transient dissolution/precipitation and halide redox promote formation of metal interstitials (Ni<sub>i</sub>,Mn<sub>i</sub>) paired with cation vacancies on the normal sublattices, with a valence shifts (Mn<sup>4</sup><sup>+</sup>→Mn<sup>3+</sup>). We also report that, in the absence of annealing, these samples undergo a negative aging with a decrease in resistance over time, further supporting the role of the flux modifying the oxidation state and site occupancy. These results demonstrate that cold sintering, when paired with strategic annealing, can produce high thermistor performance with a thermally stable NTC ceramics at a fraction of the processing energy and temperature, with tunable electrical properties driven by the molten salt flux chemistry.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118172"},"PeriodicalIF":6.2,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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