Pub Date : 2025-04-23DOI: 10.1016/j.jeurceramsoc.2025.117480
Huanrong Tian , Xu Zhou , Zidong Zhang , Haitao Wu , Yao Liu
Addressing the critical demand for ultra-low relative permittivity ceramics in advanced communication systems, this study developed a novel Mg2P4O12 metaphosphate ceramic. At microwave frequencies, it exhibits excellent performance with εr = 4.61 ± 0.08, Q×f = 51,073 ± 1716 GHz, and τf = −11.46 ± 2.1 ppm/℃, offering significant advantages in low-latency transmission and high temperature stability. Additionally, its low bulk density (∼ 2.50 g/cm3) supports lightweight design of electronic devices. Terahertz time-domain spectroscopy further demonstrated its excellent submillimeter-wave dielectric performance, suggesting potential for achieving higher Q×f values. Consequently, 5 wt% H3BO3 was introduced to improve sintering characteristics, significantly enhancing the quality factor to 61,757 ( ± 1608) GHz. To validate practical application, a broadband DRA was designed using Mg2P4O12+ 5 wt% H3BO3 ceramics, achieving an impressive bandwidth of 27.4 % and high gain of 7.3 dBi, demonstrating great potential for radar communication applications.
{"title":"A novel ultra-low relative permittivity Mg2P4O12 metaphosphate ceramic for dielectric resonator antennas","authors":"Huanrong Tian , Xu Zhou , Zidong Zhang , Haitao Wu , Yao Liu","doi":"10.1016/j.jeurceramsoc.2025.117480","DOIUrl":"10.1016/j.jeurceramsoc.2025.117480","url":null,"abstract":"<div><div>Addressing the critical demand for ultra-low relative permittivity ceramics in advanced communication systems, this study developed a novel Mg<sub>2</sub>P<sub>4</sub>O<sub>12</sub> metaphosphate ceramic. At microwave frequencies, it exhibits excellent performance with <em>ε</em><sub>r</sub> = 4.61 ± 0.08, <em>Q×f</em> = 51,073 ± 1716 GHz, and <em>τ</em><sub>f</sub> = −11.46 ± 2.1 ppm/℃, offering significant advantages in low-latency transmission and high temperature stability. Additionally, its low bulk density (∼ 2.50 g/cm<sup>3</sup>) supports lightweight design of electronic devices. Terahertz time-domain spectroscopy further demonstrated its excellent submillimeter-wave dielectric performance, suggesting potential for achieving higher <em>Q×f</em> values. Consequently, 5 wt% H<sub>3</sub>BO<sub>3</sub> was introduced to improve sintering characteristics, significantly enhancing the quality factor to 61,757 ( ± 1608) GHz. To validate practical application, a broadband DRA was designed using Mg<sub>2</sub>P<sub>4</sub>O<sub>12</sub>+ 5 wt% H<sub>3</sub>BO<sub>3</sub> ceramics, achieving an impressive bandwidth of 27.4 % and high gain of 7.3 dBi, demonstrating great potential for radar communication applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 13","pages":"Article 117480"},"PeriodicalIF":5.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874982","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 : 2025-04-23DOI: 10.1016/j.jeurceramsoc.2025.117479
Jianxin Zheng , Yuan Lin , Tongguo Huo , Dan Zhu , Yanyan Wang , Ziwei Wang , Siqing Wang , Yu Dai , Jian Wu
Using a self-made ZrC-TaC composite liquid precursor, we introduced ZrxTa1-xC solid solution ceramics into a C/C composite matrix via precursor impregnation and pyrolysis (PIP) to fabricate C/C-ZrxTa1-xC composites. By optimizing the Zr/Ta ratio, C/C-ZrxTa1-xC composites with excellent mechanical and ablative properties were prepared. For the Zr/Ta ratio of 6:1, the composite exhibits a flexural strength of 166.16 ± 13.84 MPa and a flexural modulus of 24.43 ± 2.28 GPa. Under an oxyacetylene flame with a heat flux of 4.18 MW/m², the composite with a Zr/Ta molar ratio of 12:1 exhibited the lowest mass and linear ablation rates of 1.98 mg/s and 5.91 μm/s, respectively. This is because during the ablation process, the Zr-Ta-O composite oxide layer characterized by a solid ZrO2 framework and liquid phases of Zr6Ta2O17 and Ta2O5 as pore fillers effectively prevented further oxygen intrusion into the matrix, thereby significantly enhancing ablation performance.
{"title":"Preparation and comparative study on the mechanical properties and ablation behavior of C/C-ZrxTa1-xC composites","authors":"Jianxin Zheng , Yuan Lin , Tongguo Huo , Dan Zhu , Yanyan Wang , Ziwei Wang , Siqing Wang , Yu Dai , Jian Wu","doi":"10.1016/j.jeurceramsoc.2025.117479","DOIUrl":"10.1016/j.jeurceramsoc.2025.117479","url":null,"abstract":"<div><div>Using a self-made ZrC-TaC composite liquid precursor, we introduced Zr<sub>x</sub>Ta<sub>1-x</sub>C solid solution ceramics into a C/C composite matrix via precursor impregnation and pyrolysis (PIP) to fabricate C/C-Zr<sub>x</sub>Ta<sub>1-x</sub>C composites. By optimizing the Zr/Ta ratio, C/C-Zr<sub>x</sub>Ta<sub>1-x</sub>C composites with excellent mechanical and ablative properties were prepared. For the Zr/Ta ratio of 6:1, the composite exhibits a flexural strength of 166.16 ± 13.84 MPa and a flexural modulus of 24.43 ± 2.28 GPa. Under an oxyacetylene flame with a heat flux of 4.18 MW/m², the composite with a Zr/Ta molar ratio of 12:1 exhibited the lowest mass and linear ablation rates of 1.98 mg/s and 5.91 μm/s, respectively. This is because during the ablation process, the Zr-Ta-O composite oxide layer characterized by a solid ZrO<sub>2</sub> framework and liquid phases of Zr<sub>6</sub>Ta<sub>2</sub>O<sub>17</sub> and Ta<sub>2</sub>O<sub>5</sub> as pore fillers effectively prevented further oxygen intrusion into the matrix, thereby significantly enhancing ablation performance.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 13","pages":"Article 117479"},"PeriodicalIF":5.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868949","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 : 2025-04-23DOI: 10.1016/j.jeurceramsoc.2025.117478
Zhipeng Fu , Lingfei Zhang , Changlian Chen , Shuai Yang , Rongqi Xu , Xianliang Fu , Li Zhu , Hebin Shi , Man Xu
Silicon carbide (SiC) ceramic membranes are renowned for their excellent properties, finding extensive applications across various fields. However, achieving a balance between porosity and strength poses a persistent challenge. This study uses a freeze-drying method to prepare a silica sol-starch composite xerogel as a pore-forming agent. The structural stability of the composite xerogel plays a critical role in supporting the pore structure during pressing, thus enhancing porosity and achieving a homogeneous microstructure. At approximately 1400 °C, carbon derived from the starch carbonizes and reacts with SiO2 in the pore-forming agent via a carbothermal reduction, generating fine SiC particles. These particles further undergo recrystallization among the starting SiC particles, forming uniform pore structures to improve open porosity and robust sintering necks. With the pore-forming agent's dosage optimized to 15 %, the resulting high open porosity of 55.6 %, enhanced permeability, and improved mechanical strength of 54.9 MPa.
{"title":"High porosity and robust strength silicon carbide ceramic membrane for water treatment","authors":"Zhipeng Fu , Lingfei Zhang , Changlian Chen , Shuai Yang , Rongqi Xu , Xianliang Fu , Li Zhu , Hebin Shi , Man Xu","doi":"10.1016/j.jeurceramsoc.2025.117478","DOIUrl":"10.1016/j.jeurceramsoc.2025.117478","url":null,"abstract":"<div><div>Silicon carbide (SiC) ceramic membranes are renowned for their excellent properties, finding extensive applications across various fields. However, achieving a balance between porosity and strength poses a persistent challenge. This study uses a freeze-drying method to prepare a silica sol-starch composite xerogel as a pore-forming agent. The structural stability of the composite xerogel plays a critical role in supporting the pore structure during pressing, thus enhancing porosity and achieving a homogeneous microstructure. At approximately 1400 °C, carbon derived from the starch carbonizes and reacts with SiO<sub>2</sub> in the pore-forming agent <em>via</em> a carbothermal reduction, generating fine SiC particles. These particles further undergo recrystallization among the starting SiC particles, forming uniform pore structures to improve open porosity and robust sintering necks. With the pore-forming agent's dosage optimized to 15 %, the resulting high open porosity of 55.6 %, enhanced permeability, and improved mechanical strength of 54.9 MPa.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 13","pages":"Article 117478"},"PeriodicalIF":5.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874983","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 : 2025-04-22DOI: 10.1016/j.jeurceramsoc.2025.117476
Rajib Das, P.P. Bandyopadhyay
This report explores the tribological characteristics of BaF2-doped YSZ coatings under varying loads, speeds, and temperatures. Up to 10 N load, the friction coefficient (COF) decreases owing to elastic contact, then it stabilizes within 0.78 – 0.80 as plastic contact dominates. At 650 °C, BaF2 extrusion under high loads reduces the COF to 0.56. Increased speed further lowers the COF through debris ejection and asperity softening. The wear rate rises with load and speed owing to Hertzian stress and tangential impact, respectively. Fatigue and abrasive wear are the main wear mechanisms. BaF2 layer provides significant wear protection, and with temperature, its shear strength reduces, lowering the COF to 0.39 and wear rate to 5.36 × 10−4 mm3/Nm at 750 °C.
{"title":"Influence of load, sliding speed, and temperature on the tribological behavior of plasma sprayed BaF2-doped YSZ composite coatings","authors":"Rajib Das, P.P. Bandyopadhyay","doi":"10.1016/j.jeurceramsoc.2025.117476","DOIUrl":"10.1016/j.jeurceramsoc.2025.117476","url":null,"abstract":"<div><div>This report explores the tribological characteristics of BaF<sub>2</sub>-doped YSZ coatings under varying loads, speeds, and temperatures. Up to 10 N load, the friction coefficient (COF) decreases owing to elastic contact, then it stabilizes within 0.78 – 0.80 as plastic contact dominates. At 650 °C, BaF<sub>2</sub> extrusion under high loads reduces the COF to 0.56. Increased speed further lowers the COF through debris ejection and asperity softening. The wear rate rises with load and speed owing to Hertzian stress and tangential impact, respectively. Fatigue and abrasive wear are the main wear mechanisms. BaF<sub>2</sub> layer provides significant wear protection, and with temperature, its shear strength reduces, lowering the COF to 0.39 and wear rate to 5.36 × 10<sup>−4</sup> mm<sup>3</sup>/Nm at 750 °C.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 13","pages":"Article 117476"},"PeriodicalIF":5.8,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865132","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 : 2025-04-21DOI: 10.1016/j.jeurceramsoc.2025.117473
Chuchu Ma, Tianyang Li, Youyuan Wang, Yao Zhang, Qian Cao, Xiaolong Gong, Xian Zeng, Xudong Cheng, Kai Liu
In this paper, high-temperature self-lubricating wear-resistant YSZ-Al2O3-CaF2-C composite coatings were prepared on the surface of 3D-printed SiC ceramics using nano-ZrO2 modification assisted with plasma spraying technology. This study focuses on the tribological behavior and mechanism of the composite coatings between room temperature and 600 °C. From room temperature to 600 °C, the composite coatings' friction coefficients and volumetric wear rates fell between 0.151 and 0.496 and 0.91 × 10−5 and 5.58 × 10−5 mm³ /N·m, respectively. During friction, the self-lubricating effect of C at room temperature and CaF2 at high temperature (above 400 °C) can produce a lubricating film and effectively reduce the friction coefficient of the composite coatings. Microscopic analysis revealed that the primary wear characteristics of the composite coatings are abrasive chips, grooves, and Si transfer layers, demonstrating that the wear mechanisms are abrasive wear and adhesive wear. It indicates that the high-temperature self-lubricating and wear-resistant performance of the YSZ-Al2O3-CaF2-C composite coatings can be significantly improved by designing the material components, which is of great significance for the application of wear-resistant ceramic parts in aerospace industry.
{"title":"Tribological behavior and mechanism of high-temperature self-lubricating wear-resistant composite coatings on 3D-printed SiC ceramic surfaces","authors":"Chuchu Ma, Tianyang Li, Youyuan Wang, Yao Zhang, Qian Cao, Xiaolong Gong, Xian Zeng, Xudong Cheng, Kai Liu","doi":"10.1016/j.jeurceramsoc.2025.117473","DOIUrl":"10.1016/j.jeurceramsoc.2025.117473","url":null,"abstract":"<div><div>In this paper, high-temperature self-lubricating wear-resistant YSZ-Al<sub>2</sub>O<sub>3</sub>-CaF<sub>2</sub>-C composite coatings were prepared on the surface of 3D-printed SiC ceramics using nano-ZrO<sub>2</sub> modification assisted with plasma spraying technology. This study focuses on the tribological behavior and mechanism of the composite coatings between room temperature and 600 °C. From room temperature to 600 °C, the composite coatings' friction coefficients and volumetric wear rates fell between 0.151 and 0.496 and 0.91 × 10<sup>−5</sup> and 5.58 × 10<sup>−5</sup> mm³ /N·m, respectively. During friction, the self-lubricating effect of C at room temperature and CaF<sub>2</sub> at high temperature (above 400 °C) can produce a lubricating film and effectively reduce the friction coefficient of the composite coatings. Microscopic analysis revealed that the primary wear characteristics of the composite coatings are abrasive chips, grooves, and Si transfer layers, demonstrating that the wear mechanisms are abrasive wear and adhesive wear. It indicates that the high-temperature self-lubricating and wear-resistant performance of the YSZ-Al<sub>2</sub>O<sub>3</sub>-CaF<sub>2</sub>-C composite coatings can be significantly improved by designing the material components, which is of great significance for the application of wear-resistant ceramic parts in aerospace industry.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 13","pages":"Article 117473"},"PeriodicalIF":5.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874981","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 : 2025-04-21DOI: 10.1016/j.jeurceramsoc.2025.117475
Ruifeng Wu , Yafei Liu , Hao Sun , Aimin Chang , Bo Zhang
BaSm2Ti4O12 (BSTO) material is promising for high-temperature thermistor applications owing to its excellent thermal stability and sensitivity coefficients. However, above 973 K, the increase in oxygen vacancies triggers the self-compensating effect of BSTO, leading to a de-localization of the localized states in the forbidden band and electrical properties deviating from the Arrhenius equation. Herein, we propose a Passive Variable-Range Hopping (PVRH) conduction mechanism to explain the nonlinear nature. Meanwhile, we suppress oxygen vacancy formation using Tb3.5 + doping and enhance structural stability through high-temperature aging, ensuring the electrical properties of BSTO materials follow the Arrhenius equation. In particular, the electrical properties of the BaTb0.2Sm1.8Ti4O12-δ sample demonstrate an excellent linear correlation with the Arrhenius equation, achieving a Pearson coefficient of 99.992 % across 723–1273 K. and maintaining a sensitivity coefficient as high as −1.28 % at 1273 K. This study provides valuable theoretical support for the development of high-temperature thermistors with high-precision.
{"title":"Suppressing intrinsic self-compensating of BaSm2Ti4O12-δ ceramics for high-temperature thermistor application","authors":"Ruifeng Wu , Yafei Liu , Hao Sun , Aimin Chang , Bo Zhang","doi":"10.1016/j.jeurceramsoc.2025.117475","DOIUrl":"10.1016/j.jeurceramsoc.2025.117475","url":null,"abstract":"<div><div>BaSm<sub>2</sub>Ti<sub>4</sub>O<sub>12</sub> (BSTO) material is promising for high-temperature thermistor applications owing to its excellent thermal stability and sensitivity coefficients. However, above 973 K, the increase in oxygen vacancies triggers the self-compensating effect of BSTO, leading to a de-localization of the localized states in the forbidden band and electrical properties deviating from the Arrhenius equation. Herein, we propose a Passive Variable-Range Hopping (PVRH) conduction mechanism to explain the nonlinear nature. Meanwhile, we suppress oxygen vacancy formation using Tb<sup>3.5 +</sup> doping and enhance structural stability through high-temperature aging, ensuring the electrical properties of BSTO materials follow the Arrhenius equation. In particular, the electrical properties of the BaTb<sub>0.2</sub>Sm<sub>1.8</sub>Ti<sub>4</sub>O<sub>12-<em>δ</em></sub> sample demonstrate an excellent linear correlation with the Arrhenius equation, achieving a Pearson coefficient of 99.992 % across 723–1273 K. and maintaining a sensitivity coefficient as high as −1.28 % at 1273 K. This study provides valuable theoretical support for the development of high-temperature thermistors with high-precision.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 12","pages":"Article 117475"},"PeriodicalIF":5.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869023","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 : 2025-04-21DOI: 10.1016/j.jeurceramsoc.2025.117472
Yang Liu, Craig J. Williams, Ping Xiao, Ying Chen
We report a study on grain boundary (GB) embrittlement in yttria stabilised zirconia (YSZ) ceramics induced by calcia-magnesia-alumino-silicate (CMAS). Model ceramics composed of tetragonal YSZ grains and intergranular CMAS were fabricated through sintering of YSZ-CMAS powder mixtures with incremental CMAS additions up to 1 wt%. Microstructural characterisations reveal that, although glassy CMAS films are present at triple junctions and between YSZ grains, most GBs are free of glassy films but enriched with CMAS-derived impurities. As the CMAS content increases the fracture toughness drops significantly, and the fracture mode shifts increasingly towards intergranular. Fractographic analysis at the atomic scale shows that fractures occur within the cores of glass-free GBs, whereas in GBs containing glassy CMAS films, fractures occur at the CMAS/YSZ interface, where a 2 nm layer of monoclinic YSZ is present. The CMAS-induced grain boundary embrittlement is explained from the perspective of fracture energy, with contributions from GB energy, ionic bonding, oxygen vacancies and ionic size mismatch taken into consideration.
{"title":"Atomic-scale insights into CMAS-induced grain boundary embrittlement in thermal barrier ceramics","authors":"Yang Liu, Craig J. Williams, Ping Xiao, Ying Chen","doi":"10.1016/j.jeurceramsoc.2025.117472","DOIUrl":"10.1016/j.jeurceramsoc.2025.117472","url":null,"abstract":"<div><div>We report a study on grain boundary (GB) embrittlement in yttria stabilised zirconia (YSZ) ceramics induced by calcia-magnesia-alumino-silicate (CMAS). Model ceramics composed of tetragonal YSZ grains and intergranular CMAS were fabricated through sintering of YSZ-CMAS powder mixtures with incremental CMAS additions up to 1 wt%. Microstructural characterisations reveal that, although glassy CMAS films are present at triple junctions and between YSZ grains, most GBs are free of glassy films but enriched with CMAS-derived impurities. As the CMAS content increases the fracture toughness drops significantly, and the fracture mode shifts increasingly towards intergranular. Fractographic analysis at the atomic scale shows that fractures occur within the cores of glass-free GBs, whereas in GBs containing glassy CMAS films, fractures occur at the CMAS/YSZ interface, where a 2 nm layer of monoclinic YSZ is present. The CMAS-induced grain boundary embrittlement is explained from the perspective of fracture energy, with contributions from GB energy, ionic bonding, oxygen vacancies and ionic size mismatch taken into consideration.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 12","pages":"Article 117472"},"PeriodicalIF":5.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874790","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 : 2025-04-17DOI: 10.1016/j.jeurceramsoc.2025.117468
Xingyu Huo , Zelai Cheng , Yuanxun Li , Yulan Jing , Xiuling Yang , Mingshan Qu , Hua Su
As a substrate material for microstrip patch antennas, enhancing the high-frequency magneto-dielectric properties of ferrite is a crucial research challenge. Herein, a series of Zn2+-Mn3+ co-substituted Ba1.5Sr1.5Co2-xZnxMnyFe23-yO41-δ hexaferrites is reported. The phase composition, crystal structure, microstructure, ion valence and magneto-dielectric properties of the samples are systematically investigated. The study reveals that the hexaferrite with x = y = 0.4 has superior magneto-dielectric properties due to its single phase, highly compact, enhanced permeability and dielectric constant, and low magnetic and dielectric losses. Meanwhile, its miniaturization factor (n) exceeds 17 while the normalization constant approaches 1, representing the excellent high-frequency magneto-dielectric properties. Finally, a rectangular microstrip patch antenna is designed and simulated using the optimized hexaferrite. It demonstrates an operational frequency of 0.8 GHz, small size, and excellent radiation performance with = -19.43 dB, BW = 346 MHz, and VSWR = 1.86.
{"title":"Investigation of Zn2+-Mn3+ co-substituted Z-type hexaferrite for patch antenna application","authors":"Xingyu Huo , Zelai Cheng , Yuanxun Li , Yulan Jing , Xiuling Yang , Mingshan Qu , Hua Su","doi":"10.1016/j.jeurceramsoc.2025.117468","DOIUrl":"10.1016/j.jeurceramsoc.2025.117468","url":null,"abstract":"<div><div>As a substrate material for microstrip patch antennas, enhancing the high-frequency magneto-dielectric properties of ferrite is a crucial research challenge. Herein, a series of Zn<sup>2+</sup>-Mn<sup>3+</sup> co-substituted Ba<sub>1.5</sub>Sr<sub>1.5</sub>Co<sub>2-<em>x</em></sub>Zn<sub><em>x</em></sub>Mn<sub><em>y</em></sub>Fe<sub>23-<em>y</em></sub>O<sub>41-δ</sub> hexaferrites is reported. The phase composition, crystal structure, microstructure, ion valence and magneto-dielectric properties of the samples are systematically investigated. The study reveals that the hexaferrite with <em>x</em> = <em>y</em> = 0.4 has superior magneto-dielectric properties due to its single phase, highly compact, enhanced permeability and dielectric constant, and low magnetic and dielectric losses. Meanwhile, its miniaturization factor (<em>n</em>) exceeds 17 while the normalization constant approaches 1, representing the excellent high-frequency magneto-dielectric properties. Finally, a rectangular microstrip patch antenna is designed and simulated using the optimized hexaferrite. It demonstrates an operational frequency of 0.8 GHz, small size, and excellent radiation performance with <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>11</mn></mrow></msub></math></span> = -19.43 dB, BW = 346 MHz, and VSWR = 1.86.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 12","pages":"Article 117468"},"PeriodicalIF":5.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868809","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 : 2025-04-15DOI: 10.1016/j.jeurceramsoc.2025.117464
Heloisa Ramlow , Hossein Ghasemi-Tabasi , Andreas Burn , Michael Harald Bayer , Gurdial Blugan
Technological advancements are expanding applications for alumina-to-metal components with higher performance demands, such as microelectronic packaging, wear-resistant components for aircraft, biomedical applications, and more. Manufacturing methods for reliable alumina-metal joints are reviewed. While diffusion bonding was initially significant, conventional brazing now leads in research and industrial use. Current efforts focus on developing active interlayers to improve alumina wetting and composite fillers to strengthen brazed joints. Diffusion bonding remains under study, but long joining times limit industrial adoption. Induction brazing, transient liquid phase bonding, and laser welding are emerging with enhanced efficiency, minimizing energy consumption, and a more sustainable process overall. Ultrasonic vibration-assisted brazing is also a promising joining technique, however, the joint temperature resistance is reduced. Future trends in the joining alumina-metal are directed to fast and flash joining techniques, hybrid joining processes, and the comprehension of the mechanisms underlying joint strength variations with differing processes under different joining conditions.
{"title":"Joining alumina to metals: Technologies, challenges, and future prospects for high-performance structures","authors":"Heloisa Ramlow , Hossein Ghasemi-Tabasi , Andreas Burn , Michael Harald Bayer , Gurdial Blugan","doi":"10.1016/j.jeurceramsoc.2025.117464","DOIUrl":"10.1016/j.jeurceramsoc.2025.117464","url":null,"abstract":"<div><div>Technological advancements are expanding applications for alumina-to-metal components with higher performance demands, such as microelectronic packaging, wear-resistant components for aircraft, biomedical applications, and more. Manufacturing methods for reliable alumina-metal joints are reviewed. While diffusion bonding was initially significant, conventional brazing now leads in research and industrial use. Current efforts focus on developing active interlayers to improve alumina wetting and composite fillers to strengthen brazed joints. Diffusion bonding remains under study, but long joining times limit industrial adoption. Induction brazing, transient liquid phase bonding, and laser welding are emerging with enhanced efficiency, minimizing energy consumption, and a more sustainable process overall. Ultrasonic vibration-assisted brazing is also a promising joining technique, however, the joint temperature resistance is reduced. Future trends in the joining alumina-metal are directed to fast and flash joining techniques, hybrid joining processes, and the comprehension of the mechanisms underlying joint strength variations with differing processes under different joining conditions.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 12","pages":"Article 117464"},"PeriodicalIF":5.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838974","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 : 2025-04-15DOI: 10.1016/j.jeurceramsoc.2025.117460
Mengfan Song , Tianran Zhang , Siyu Zhang , Siyuan Li , Ruirui Kang , Fang Kang , Lixue Zhang , Jiping Wang
Antiferroelectric materials have garnered considerable interest for pulsed power applications because of their reversible antiferroelectric-ferroelectric (AFE-FE) phase transition under an electric field. However, pure NaNbO3 exhibits ferroelectric phase characteristics at room temperature under an electric field, resulting in low energy storage performance. We prepared lead-free (Na1–1.5xBixLa0.5x)(Nb1-xMgx)O3 ceramics via inducing local antiferroelectric phases coexistence by ion co-doping. The P-R phase transition temperature was shifted below room temperature, which promotes the formation of polar nanoregions and achieves a favorable ΔP value (52 μC·cm−2) when x = 0.06. Consequently, the sample with x = 0.06 achieved a high energy storage density (8.24 J·cm−3), energy storage efficiency (93.7 %), and energy storage potential (23.54 J·cm−2·MV−1) at 350 kV·cm−1, while exhibiting excellent frequency (1–1000 Hz) and temperature (25–150 °C) stability. This work presents a practical approach to develop capacitors with high energy storage performance for other systems under the same electric field range.
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