Pub Date : 2025-02-25DOI: 10.1016/j.jeurceramsoc.2025.117326
Kyung Joo Lee , Jae Won Lee , Changgeon Lee , Minju Kim , Ohhun Gwon , Seungwoo Son , Byung Sung Kang , Woo-Jin Choi , Wook Jo , Seok-Hyun Yoon , Yunjung Park , Jinsung Chun
This study demonstrates that the low shell-forming temperatures of Mg in powdered form can effectively control Dy diffusion into BaTiO3. For Dy pre-coated BaTiO3, the insulation resistance is higher due to an increased shell thickness compared to Mg pre-coated BaTiO3. However, the thermal activation energy and ohmic conduction slope exhibit comparable values for both Dy and Mg pre-coated BaTiO3. Moreover, the high resistance and low dielectric permittivity observed in Dy pre-coated BaTiO3 are attributed to B-site substitution of BaTiO3 by the significant Dy dopant content. In contrast, the high coercive field and low resistance for Mg pre-coated BaTiO3 result from Dy aggregation caused by inhibited Dy diffusion. This study offers valuable insights into optimizing rare-earth element diffusion strategies to satisfy diverse application requirements in multilayer ceramic capacitors.
{"title":"Modulation of rare-earth diffusion for tailoring diverse MLCC application requirements","authors":"Kyung Joo Lee , Jae Won Lee , Changgeon Lee , Minju Kim , Ohhun Gwon , Seungwoo Son , Byung Sung Kang , Woo-Jin Choi , Wook Jo , Seok-Hyun Yoon , Yunjung Park , Jinsung Chun","doi":"10.1016/j.jeurceramsoc.2025.117326","DOIUrl":"10.1016/j.jeurceramsoc.2025.117326","url":null,"abstract":"<div><div>This study demonstrates that the low shell-forming temperatures of Mg in powdered form can effectively control Dy diffusion into BaTiO<sub>3</sub>. For Dy pre-coated BaTiO<sub>3</sub>, the insulation resistance is higher due to an increased shell thickness compared to Mg pre-coated BaTiO<sub>3</sub>. However, the thermal activation energy and ohmic conduction slope exhibit comparable values for both Dy and Mg pre-coated BaTiO<sub>3</sub>. Moreover, the high resistance and low dielectric permittivity observed in Dy pre-coated BaTiO<sub>3</sub> are attributed to B-site substitution of BaTiO<sub>3</sub> by the significant Dy dopant content. In contrast, the high coercive field and low resistance for Mg pre-coated BaTiO<sub>3</sub> result from Dy aggregation caused by inhibited Dy diffusion. This study offers valuable insights into optimizing rare-earth element diffusion strategies to satisfy diverse application requirements in multilayer ceramic capacitors.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117326"},"PeriodicalIF":5.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510647","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 : 2025-02-23DOI: 10.1016/j.jeurceramsoc.2025.117319
Aleksei A. Polkovnikov , Ilya O. Yurev , Maxim S. Molokeev , Aleksandr P. Tyutyunnik , Roza I. Gulyaeva , Nikita A. Shulaev , Maxim V. Kudomanov , Vitaly G. Bamburov , Oleg V. Andreev
Samarium monosulfide (SmS) is a unique tensometric material. For the first time, SmS ceramics for magnetron sputtering films were synthesized. A powder of up to 100 mol% SmS was produced via the reaction of γ-Sm2S2.98 with excess metallic samarium vapor. The conditions for target and side reactions were determined. SmS ceramic targets were fabricated by pressing under standard conditions and annealed at high temperatures. Ceramic properties—density, hardness, and compressive strength—improved with increasing pressing pressure. Conditions for stable magnetron discharge over the SmS target were established. The composition of films deposited on silicon substrates varies with the substrate-to-target angle, transitioning from SmS1.9 to SmS. During magnetron discharge, SmS dissociates into samarium and sulfur, with their distribution approximated by angular equations. High-mass Sm and SmS particles distribute radially, while sulfur concentration forms an ellipse elongated toward low angles. The deposition angle range for SmS was determined.
{"title":"Samarium monosulfide ceramics: Preparation and properties","authors":"Aleksei A. Polkovnikov , Ilya O. Yurev , Maxim S. Molokeev , Aleksandr P. Tyutyunnik , Roza I. Gulyaeva , Nikita A. Shulaev , Maxim V. Kudomanov , Vitaly G. Bamburov , Oleg V. Andreev","doi":"10.1016/j.jeurceramsoc.2025.117319","DOIUrl":"10.1016/j.jeurceramsoc.2025.117319","url":null,"abstract":"<div><div>Samarium monosulfide (SmS) is a unique tensometric material. For the first time, SmS ceramics for magnetron sputtering films were synthesized. A powder of up to 100 mol% SmS was produced via the reaction of γ-Sm<sub>2</sub>S<sub>2.98</sub> with excess metallic samarium vapor. The conditions for target and side reactions were determined. SmS ceramic targets were fabricated by pressing under standard conditions and annealed at high temperatures. Ceramic properties—density, hardness, and compressive strength—improved with increasing pressing pressure. Conditions for stable magnetron discharge over the SmS target were established. The composition of films deposited on silicon substrates varies with the substrate-to-target angle, transitioning from SmS<sub>1.9</sub> to SmS. During magnetron discharge, SmS dissociates into samarium and sulfur, with their distribution approximated by angular equations. High-mass Sm and SmS particles distribute radially, while sulfur concentration forms an ellipse elongated toward low angles. The deposition angle range for SmS was determined.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117319"},"PeriodicalIF":5.8,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512407","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 : 2025-02-23DOI: 10.1016/j.jeurceramsoc.2025.117324
Lallie Quemeras , Manon Fernandez , Guillaume Couégnat , Mattéo Gaget , Thomas Vandellos , Francis Rebillat
Environmental Barrier Coating (EBC) systems are currently applied on silicon carbides (SiC) ceramic matrix composites (CMC) to protect them from the harsh environmental conditions of aircraft engines. During the thermal cycles of engines, various physicochemical and thermomechanical mechanisms damage the coating. These damages lead to the loss of the protection efficiency of the EBC up to its spallation. This work is focused on two main types of damages: the bond coat oxidation, which causes local stresses induced by volume variations with the formation of oxide scale, and the thermomechanical stresses across this layered system: CMC/bond coat/oxide/EBC. Oxidation tests (moist air) were carried out on polished Si samples and coated samples to discuss the effect of interface roughness and the presence of the top coat on kinetics and the stress generation.
{"title":"Oxidation damage mechanisms of the CMC/Si/YDS system at high temperature: Kinetic, morphological and mechanical characterization","authors":"Lallie Quemeras , Manon Fernandez , Guillaume Couégnat , Mattéo Gaget , Thomas Vandellos , Francis Rebillat","doi":"10.1016/j.jeurceramsoc.2025.117324","DOIUrl":"10.1016/j.jeurceramsoc.2025.117324","url":null,"abstract":"<div><div>Environmental Barrier Coating (EBC) systems are currently applied on silicon carbides (SiC) ceramic matrix composites (CMC) to protect them from the harsh environmental conditions of aircraft engines. During the thermal cycles of engines, various physicochemical and thermomechanical mechanisms damage the coating. These damages lead to the loss of the protection efficiency of the EBC up to its spallation. This work is focused on two main types of damages: the bond coat oxidation, which causes local stresses induced by volume variations with the formation of oxide scale, and the thermomechanical stresses across this layered system: CMC/bond coat/oxide/EBC. Oxidation tests (moist air) were carried out on polished Si samples and coated samples to discuss the effect of interface roughness and the presence of the top coat on kinetics and the stress generation.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117324"},"PeriodicalIF":5.8,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510648","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 : 2025-02-22DOI: 10.1016/j.jeurceramsoc.2025.117317
Adam Berrais, Alicia Weibel, David Mesguich, Geoffroy Chevallier, Viviane Turq, Claude Estournès, Christophe Laurent
The Spark Plasma Sintering of few-layer-graphene (FLG)-Si3N4 powders, prepared by the chemical vapor deposition of carbon from methane, produces dense nanocomposites for samples with up to 24.9 vol% of carbon. The samples are characterized by several techniques including Raman spectroscopy, scanning and transmission electron microscopy. The reorganization of the FLG islands/films into FLG nanoplatelets is avoided if moderate amounts of sintering additives are used, therefore minimizing liquid phase formation. A novel microstructure with FLG films at the grain boundaries of Si3N4 is obtained for a sample with very high carbon content. This sample shows high electrical conductivity (15.7 S/cm), moderate fracture strength (320 MPa) and SENB toughness (3.8 MPa.m1/2), low microhardness (5.6 GPa) and low friction coefficient against a WC-Co ball due to the formation of a carbon tribofilm in the contact. Controlling the carbon content and the FLG microstructure (platelets and/or films) gives properties that may fit different applications.
{"title":"Few-layered graphene - Si3N4 nanocomposites prepared by Spark Plasma Sintering: Microstructure and properties","authors":"Adam Berrais, Alicia Weibel, David Mesguich, Geoffroy Chevallier, Viviane Turq, Claude Estournès, Christophe Laurent","doi":"10.1016/j.jeurceramsoc.2025.117317","DOIUrl":"10.1016/j.jeurceramsoc.2025.117317","url":null,"abstract":"<div><div>The Spark Plasma Sintering of few-layer-graphene (FLG)-Si<sub>3</sub>N<sub>4</sub> powders, prepared by the chemical vapor deposition of carbon from methane, produces dense nanocomposites for samples with up to 24.9 vol% of carbon. The samples are characterized by several techniques including Raman spectroscopy, scanning and transmission electron microscopy. The reorganization of the FLG islands/films into FLG nanoplatelets is avoided if moderate amounts of sintering additives are used, therefore minimizing liquid phase formation. A novel microstructure with FLG films at the grain boundaries of Si<sub>3</sub>N<sub>4</sub> is obtained for a sample with very high carbon content. This sample shows high electrical conductivity (15.7 S/cm), moderate fracture strength (320 MPa) and SENB toughness (3.8 MPa.m<sup>1/2</sup>), low microhardness (5.6 GPa) and low friction coefficient against a WC-Co ball due to the formation of a carbon tribofilm in the contact. Controlling the carbon content and the FLG microstructure (platelets and/or films) gives properties that may fit different applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117317"},"PeriodicalIF":5.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-21DOI: 10.1016/j.jeurceramsoc.2025.117318
Xinru Yang , Zhiyuan Zhao , Liping Tong , Zhongyang Wang , Xiao Zhou , Tongxiang Fan
Large variable emissivity materials play a key role in smart thermal control. However, conventional variable emissivity materials have limitations, including insufficient variability and unclear understanding of how phase-change temperature and emissivity variation relates. In this study, LaMnO3-based (ABO3) perovskite materials doped with ions of varying radii were prepared. Among them, La0.7Ba0.2Cd0.1MnO3 showed a variable emissivity of 0.467 and a Curie temperature of 290 K. Combining experimental studies with density functional theory calculation reveals that the mechanism for tuning the Curie temperature is linked to the displacement of A-site ions, resulting from the distortion of the MnO6 octahedron. Besides, the variable emissivity mechanism is explained by the densities of states, which decrease as Mn-O bond strength increases. This work explores the mechanism of phase transition temperature and emissivity changes from an intrinsic crystal structural perspective and will provide theoretical foundations for improving variable emissivity properties of smart thermal control systems.
{"title":"Effect of doping-induced MnO6 distortion on the phase transition temperature and emissivity of LaMnO3-based materials","authors":"Xinru Yang , Zhiyuan Zhao , Liping Tong , Zhongyang Wang , Xiao Zhou , Tongxiang Fan","doi":"10.1016/j.jeurceramsoc.2025.117318","DOIUrl":"10.1016/j.jeurceramsoc.2025.117318","url":null,"abstract":"<div><div>Large variable emissivity materials play a key role in smart thermal control. However, conventional variable emissivity materials have limitations, including insufficient variability and unclear understanding of how phase-change temperature and emissivity variation relates. In this study, LaMnO<sub>3</sub>-based (ABO<sub>3</sub>) perovskite materials doped with ions of varying radii were prepared. Among them, La<sub>0.7</sub>Ba<sub>0.2</sub>Cd<sub>0.1</sub>MnO<sub>3</sub> showed a variable emissivity of 0.467 and a Curie temperature of 290 K. Combining experimental studies with density functional theory calculation reveals that the mechanism for tuning the Curie temperature is linked to the displacement of A-site ions, resulting from the distortion of the MnO<sub>6</sub> octahedron. Besides, the variable emissivity mechanism is explained by the densities of states, which decrease as Mn-O bond strength increases. This work explores the mechanism of phase transition temperature and emissivity changes from an intrinsic crystal structural perspective and will provide theoretical foundations for improving variable emissivity properties of smart thermal control systems.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117318"},"PeriodicalIF":5.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487566","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}
The study presents the synthesis and characterization of high-entropy optical nanoceramics with the composition (Y₀.₂La₀.₂Gd₀.₂Eu₀.₂Er₀.₂)₂O₃, prepared via thermobaric pressing of nanopowders. A comprehensive analysis of the structural and morphological properties, as well as the chemical composition, was performed. Photoluminescence (PL) studies revealed a significant enhancement in the emission intensity of the red spectral range compared to the nanopowder. This enhancement is associated with reduced symmetry around the Eu³ ⁺ ions caused by lattice distortions due to the formation of impurity phases, as well as anionic defects. Optical transmission measurements show that the nanoceramics exhibit transparency of up to 70 % in the visible range, with an optical band gap of 5.77 eV. The increased PL quantum yield, calculated at over 50 % on the basis of measured optical properties, suggests the potential of these nanoceramics as red-emitting materials for optoelectronic applications. The study highlights the influence of configurational entropy and defect engineering on the optical performance of high-entropy oxides, providing a foundation for further exploration in photonic applications.
{"title":"High-entropy oxide optical nanoceramics prepared by thermobaric synthesis","authors":"A.N. Kiryakov , Yu.A. Kuznetsova , E.A. Buntov , T.V. Dyachkova , J. Murugan , A.Yu. Chufarov , A.P. Tyutyunnik","doi":"10.1016/j.jeurceramsoc.2025.117316","DOIUrl":"10.1016/j.jeurceramsoc.2025.117316","url":null,"abstract":"<div><div>The study presents the synthesis and characterization of high-entropy optical nanoceramics with the composition (Y₀.₂La₀.₂Gd₀.₂Eu₀.₂Er₀.₂)₂O₃, prepared via thermobaric pressing of nanopowders. A comprehensive analysis of the structural and morphological properties, as well as the chemical composition, was performed. Photoluminescence (PL) studies revealed a significant enhancement in the emission intensity of the red spectral range compared to the nanopowder. This enhancement is associated with reduced symmetry around the Eu³ ⁺ ions caused by lattice distortions due to the formation of impurity phases, as well as anionic defects. Optical transmission measurements show that the nanoceramics exhibit transparency of up to 70 % in the visible range, with an optical band gap of 5.77 eV. The increased PL quantum yield, calculated at over 50 % on the basis of measured optical properties, suggests the potential of these nanoceramics as red-emitting materials for optoelectronic applications. The study highlights the influence of configurational entropy and defect engineering on the optical performance of high-entropy oxides, providing a foundation for further exploration in photonic applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 9","pages":"Article 117316"},"PeriodicalIF":5.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463915","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}
Transparent ceramics with ultra-wide emission spectra are widely considered as the next-generation color converters for high color rendering white light emitting diodes (LEDs) and laser diodes (LDs). Herein, a novel Ce3+:Lu3Al5O12-Mn4+:K2SiF6-Y3+:CaF2 transparent ceramic phosphor was prepared by the cold sintering method. The samples sintered at 250 °C and 175 MPa exhibit considerable visible transmittance (about 43%) and uniform grain distribution with no interfacial reaction. When excited at 460 nm, the samples exhibit both broad green emission bands (Ce3+: 5d → 4 f) and sharp red peaks (Mn4+: 2Eg → 4A2g), possessing over 90% internal quantum efficiencies and quite small thermal quenching. The assembled white LED exhibits luminous efficiency (LE) of 96.4 lm/W and color rendering index (CRI) of 94.5, while the reflection-type white LD shows LE of 207.4 lm/W and CRI of 85.0. It demonstrates that the Ce3+:Lu3Al5O12-Mn4+:K2SiF6-Y3+:CaF2 transparent ceramics exhibit great potential in the high-power LED/LD lighting.
{"title":"Cold sintered Ce3+:Lu3Al5O12-Mn4+:K2SiF6-Y3+:CaF2 transparent ceramic phosphors for high color rendering white LEDs/LDs","authors":"Xiaotong Li, Rui Zhang, Xuejun Wei, Zusheng Xu, Xianzhuang Qin","doi":"10.1016/j.jeurceramsoc.2025.117315","DOIUrl":"10.1016/j.jeurceramsoc.2025.117315","url":null,"abstract":"<div><div>Transparent ceramics with ultra-wide emission spectra are widely considered as the next-generation color converters for high color rendering white light emitting diodes (LEDs) and laser diodes (LDs). Herein, a novel Ce<sup>3+</sup>:Lu<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>-Mn<sup>4+</sup>:K<sub>2</sub>SiF<sub>6</sub>-Y<sup>3+</sup>:CaF<sub>2</sub> transparent ceramic phosphor was prepared by the cold sintering method. The samples sintered at 250 °C and 175 MPa exhibit considerable visible transmittance (about 43%) and uniform grain distribution with no interfacial reaction. When excited at 460 nm, the samples exhibit both broad green emission bands (Ce<sup>3+</sup>: 5d → 4 f) and sharp red peaks (Mn<sup>4+</sup>: <sup>2</sup>E<sub>g</sub> → <sup>4</sup>A<sub>2g</sub>), possessing over 90% internal quantum efficiencies and quite small thermal quenching. The assembled white LED exhibits luminous efficiency (LE) of 96.4 lm/W and color rendering index (CRI) of 94.5, while the reflection-type white LD shows LE of 207.4 lm/W and CRI of 85.0. It demonstrates that the Ce<sup>3+</sup>:Lu<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>-Mn<sup>4+</sup>:K<sub>2</sub>SiF<sub>6</sub>-Y<sup>3+</sup>:CaF<sub>2</sub> transparent ceramics exhibit great potential in the high-power LED/LD lighting.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117315"},"PeriodicalIF":5.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480363","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 : 2025-02-19DOI: 10.1016/j.jeurceramsoc.2025.117302
Ning Liu , Xiaofan Sun , Haodong Gu , Yu Cai , Bin Zeng , Xiao You , Zhen Wang , Yanmei Kan , Jiangang Zhuang , Shaoming Dong
Heterogeneous interfaces greatly impact material electromagnetics, but combining structural design, interface regulation, and magnetic enhancement remains challenging. This study synthesizes a carbon fiber-reinforced metal-containing silicon carbonitride (Cf/PyC/SiC-SiCN(Fe)) composite by incorporating multilayer interfaces and magnetic particles. The research reveals that the existence of multiphase heterogeneous interfaces produces a plethora of lattice defects and amplifies polarization effects, thereby enhancing electromagnetic shielding performance. The addition of carbon fibers augments conductive loss, while magnetic particles contribute to magnetic loss. Their combined effect results in an impressive shielding effectiveness of 62.1 dB in the 8–12 GHz band and 38.6 dB in the 12–18 GHz band. Furthermore, the carbon fiber and double-layer interface structure provide robust mechanical support for the composite, with a strength reaching 444.8 ± 20.9 MPa. These findings illustrate that through meticulous interface design and structural optimization, the composite achieves excellent electromagnetic shielding and mechanical properties at low density, indicating wide potential applications.
{"title":"Multi-mechanism cooperative optimization of electromagnetic shielding and mechanical properties in Cf/PyC/SiC-SiCN(Fe) ceramic-based composites","authors":"Ning Liu , Xiaofan Sun , Haodong Gu , Yu Cai , Bin Zeng , Xiao You , Zhen Wang , Yanmei Kan , Jiangang Zhuang , Shaoming Dong","doi":"10.1016/j.jeurceramsoc.2025.117302","DOIUrl":"10.1016/j.jeurceramsoc.2025.117302","url":null,"abstract":"<div><div>Heterogeneous interfaces greatly impact material electromagnetics, but combining structural design, interface regulation, and magnetic enhancement remains challenging. This study synthesizes a carbon fiber-reinforced metal-containing silicon carbonitride (Cf/PyC/SiC-SiCN(Fe)) composite by incorporating multilayer interfaces and magnetic particles. The research reveals that the existence of multiphase heterogeneous interfaces produces a plethora of lattice defects and amplifies polarization effects, thereby enhancing electromagnetic shielding performance. The addition of carbon fibers augments conductive loss, while magnetic particles contribute to magnetic loss. Their combined effect results in an impressive shielding effectiveness of 62.1 dB in the 8–12 GHz band and 38.6 dB in the 12–18 GHz band. Furthermore, the carbon fiber and double-layer interface structure provide robust mechanical support for the composite, with a strength reaching 444.8 ± 20.9 MPa. These findings illustrate that through meticulous interface design and structural optimization, the composite achieves excellent electromagnetic shielding and mechanical properties at low density, indicating wide potential applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 9","pages":"Article 117302"},"PeriodicalIF":5.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445570","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 : 2025-02-18DOI: 10.1016/j.jeurceramsoc.2025.117295
Thomas Lam , Sarah Barack , Grace Dunham , Jessica Walthew , William M. Carty
This paper presents a proof-of-concept study using chemical quantification from scanning electron microscopy and electron dispersive spectroscopy (SEM-EDS) mapping of cross sections of sub-millimeter (mm) samples of two porcelain objects from the Cooper Hewitt Smithsonian Design Museum (CHSDM) to replicate European porcelain recipes for microstructural evolution experiments. Meissen and Royal Copenhagen replica porcelain bodies were fired in a custom-designed gradient furnace, allowing eight samples of each ware to be fired across a temperature range from 1089°C to 1317°C. Measurements such as bulk density and water absorption, in combination with a microanalytical methodology allowed porosity and quartz dissolution to be tracked as functions of firing temperature. Microstructural assessment including pore size comparison between the historic sample set and the newly made replica pieces suggests that both the Meissen and Royal Copenhagen objects were fired under similar conditions with the latter being over-fired.
{"title":"Microanalytical methods analyzing early European porcelains to study hard paste microstructural evolution","authors":"Thomas Lam , Sarah Barack , Grace Dunham , Jessica Walthew , William M. Carty","doi":"10.1016/j.jeurceramsoc.2025.117295","DOIUrl":"10.1016/j.jeurceramsoc.2025.117295","url":null,"abstract":"<div><div>This paper presents a proof-of-concept study using chemical quantification from scanning electron microscopy and electron dispersive spectroscopy (SEM-EDS) mapping of cross sections of sub-millimeter (mm) samples of two porcelain objects from the Cooper Hewitt Smithsonian Design Museum (CHSDM) to replicate European porcelain recipes for microstructural evolution experiments. Meissen and Royal Copenhagen replica porcelain bodies were fired in a custom-designed gradient furnace, allowing eight samples of each ware to be fired across a temperature range from 1089°C to 1317°C. Measurements such as bulk density and water absorption, in combination with a microanalytical methodology allowed porosity and quartz dissolution to be tracked as functions of firing temperature. Microstructural assessment including pore size comparison between the historic sample set and the newly made replica pieces suggests that both the Meissen and Royal Copenhagen objects were fired under similar conditions with the latter being over-fired.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 10","pages":"Article 117295"},"PeriodicalIF":5.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512409","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 : 2025-02-18DOI: 10.1016/j.jeurceramsoc.2025.117300
Qian Sun , Hao Zhang , Min Ge , Shouquan Yu , Huifeng Zhang , Weigang Zhang
In this study, near-stoichiometric SiC-ZrB2 fibers (C/Si atomic ratio = 1.05, oxygen content <0.2 wt%) were derived from amorphous Si-C-O-Zr-B fibers (C/Si atomic ratio = 1.25, oxygen content = 9.3 wt%) through following high-temperature evolution: deoxidation and removal of excess carbon (1280–1400 °C), crystallization and rapid grain growth of β-SiC (1400–1750 °C), and sintering densification (1600–1850 °C). The tensile strength and elastic modulus of SiC-ZrB2 fibers with an average diameter of 8.5 μm reached 2.1 GPa and 385 GPa, respectively. The fibers possessed a carbon-rich outer surface (∼ 110 nm), a dense surface layer (∼ 3.0 μm), and highly-crystallized microstructure with a SiC grain size of ∼ 250 nm. ZrB2 crystals and minor free carbon were distributed along SiC grain boundaries. Compared to commercial Hi-Nicalon S, Tyranno SA, and Sylramic fibers, SiC-ZrB2 fibers exhibited significantly enhanced creep resistance between 1200–1500 °C. Furthermore, the fibers exhibited excellent thermal stability, with tensile strength retention exceeding 95 % after exposure at 1800 °C for 3 h in argon.
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