Pub Date : 2025-04-01DOI: 10.1016/j.ceramint.2025.01.143
Yongqiang Yang , Yongping Pu , Lei Zhang , Bo Wang , Zhemin Chen , Min Chen , Xiang Lu , Chunhui Wu , Jinbo Zhang , Noureddine Blidi
Achieving high insulation resistivity and superior temperature stability of high permittivity simultaneously poses a significant challenge in the field of power electronics. This study employed a stepwise enhancement approach in Sr0.985Ho0.01TiO3-xwt%MgO (x = 0, 0.05, 0.15, 0.25, 0.35, 0.45) (SHT-xM) ceramics via the coordination of charge compensation (balancing Ho and Mg ions) and grain-boundary obstruction (clustering of MgO). The modified ceramics demonstrated a high permittivity (1800), excellent temperature stability (X8P, ΔC/C25°C ≤ 10 %, −50–150 °C; ΔC/C25°C ≤ 0.6 %, −40–70 °C) and exceptional insulation resistivity (1012 Ω • cm), meeting the demands of high insulation X8P capacitors. Furthermore, these outstanding properties can be attributed to charge compensation in the formation of [] and , reduction of grain size and grain-boundary pinning of MgO based on defect and structural analysis. Our study presents a novel and efficient strategy to overcoming the challenge of achieving both superior temperature stability of permittivity and high insulation resistivity.
{"title":"Stepwise optimization in MgO-modified Sr0.985Ho0.01TiO3-based ceramics for high-insulation capacitors","authors":"Yongqiang Yang , Yongping Pu , Lei Zhang , Bo Wang , Zhemin Chen , Min Chen , Xiang Lu , Chunhui Wu , Jinbo Zhang , Noureddine Blidi","doi":"10.1016/j.ceramint.2025.01.143","DOIUrl":"10.1016/j.ceramint.2025.01.143","url":null,"abstract":"<div><div>Achieving high insulation resistivity and superior temperature stability of high permittivity simultaneously poses a significant challenge in the field of power electronics. This study employed a stepwise enhancement approach in Sr<sub>0.985</sub>Ho<sub>0.01</sub>TiO<sub>3</sub>-<em>x</em><em>w</em>t%MgO (<em>x</em> = 0, 0.05, 0.15, 0.25, 0.35, 0.45) (SHT-<em>x</em>M) ceramics via the coordination of charge compensation (balancing Ho and Mg ions) and grain-boundary obstruction (clustering of MgO). The modified ceramics demonstrated a high permittivity (1800), excellent temperature stability (X8P, Δ<em>C/C</em><sub>25</sub> <sub>°C</sub> ≤ 10 %, −50–150 °C; Δ<em>C/C</em><sub>25</sub> <sub>°C</sub> ≤ 0.6 %, −40–70 °C) and exceptional insulation resistivity (10<sup>12</sup> Ω • cm), meeting the demands of high insulation X8P capacitors. Furthermore, these outstanding properties can be attributed to charge compensation in the formation of [<span><math><mrow><msubsup><mrow><mi>M</mi><mi>g</mi></mrow><mrow><mi>T</mi><mi>i</mi></mrow><mo>″</mo></msubsup><mo>−</mo><msubsup><mrow><mn>2</mn><mi>H</mi><mi>o</mi></mrow><mrow><mi>S</mi><mi>r</mi></mrow><mo>•</mo></msubsup></mrow></math></span>] and <span><math><mrow><mo>[</mo><mrow><msubsup><mrow><mi>M</mi><mi>g</mi></mrow><mrow><mi>T</mi><mi>i</mi></mrow><mo>″</mo></msubsup><mo>−</mo><msubsup><mi>V</mi><mi>O</mi><mrow><mo>•</mo><mo>•</mo></mrow></msubsup></mrow><mo>]</mo></mrow></math></span>, reduction of grain size and grain-boundary pinning of MgO based on defect and structural analysis. Our study presents a novel and efficient strategy to overcoming the challenge of achieving both superior temperature stability of permittivity and high insulation resistivity.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 12984-12991"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814791","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 : 2025-04-01DOI: 10.1016/j.ceramint.2024.09.251
Roman D. Mukhachev , Semyon T. Baidak , Alexey V. Lukoyanov
The electronic structure of the GdNiSb compound under pressure has been investigated in the course of first-principles calculations accounting for spin-orbit coupling. At ambient conditions this compound is found to be a narrow gap semiconductor with an indirect band gap of 0.38 eV. Decreasing in the cell volume leads to a gradual redistribution of the density of states caused by band broadening and partial delocalization of the electronic states, in particular the 3d Ni states are strongly modified. The band gap is closed when the volume of the lattice decreases by 35 % or more with a slight metallization at the Fermi energy with the appearance of the Fermi surfaces. For the smaller volumes, the metallic states with non-trivial topological features are calculated for GdNiSb.
在第一原理计算过程中，考虑到自旋轨道耦合，研究了钆镍锑化合物在压力下的电子结构。研究发现，在环境条件下，这种化合物是一种间接带隙为 0.38 eV 的窄间隙半导体。电池体积的减小会导致电子态的带宽扩大和部分失焦，从而导致态密度逐渐重新分布，尤其是 3d Ni 态发生了强烈变化。当晶格体积减少 35% 或更多时，带隙关闭，费米能处出现轻微的金属化，费米面也随之出现。对于较小体积的钆镍锑，我们计算出了具有非三维拓扑特征的金属态。
{"title":"Narrow gap semiconductor to metal transition in GdNiSb under pressure","authors":"Roman D. Mukhachev , Semyon T. Baidak , Alexey V. Lukoyanov","doi":"10.1016/j.ceramint.2024.09.251","DOIUrl":"10.1016/j.ceramint.2024.09.251","url":null,"abstract":"<div><div>The electronic structure of the GdNiSb compound under pressure has been investigated in the course of first-principles calculations accounting for spin-orbit coupling. At ambient conditions this compound is found to be a narrow gap semiconductor with an indirect band gap of 0.38 eV. Decreasing in the cell volume leads to a gradual redistribution of the density of states caused by band broadening and partial delocalization of the electronic states, in particular the 3d Ni states are strongly modified. The band gap is closed when the volume of the lattice decreases by 35 % or more with a slight metallization at the Fermi energy with the appearance of the Fermi surfaces. For the smaller volumes, the metallic states with non-trivial topological features are calculated for GdNiSb.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 12330-12336"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262611","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 : 2025-04-01DOI: 10.1016/j.ceramint.2025.01.122
Xianzhu Zhou , Wentao Zhang , Zhou Zhao , Peicong Zhang , Ning Sun , Xiangkui Cheng
Based on the green emission of NaLa0.82SiO4:0.18Tb3+ phosphor, the luminescence properties including intensity and stability of phosphor was effectively improved via the isomorphic substitution of crystal groups including [B3+-F-]→[Si4+-O2-] and [Ba2+-F-]→[La3+-O2-]. The luminescence intensities (λem = 544 nm) of NaLa0.82Si0.96B0.04O3.96F0.04:0.18Tb3+ and NaLa0.78Ba0.04SiO3.96F0.04:0.18Tb3+ increased to 4.22 times and 5.49 times that of NaLa0.82SiO4:0.18Tb3+, respectively. Moreover, even at an operating temperature of 423 K, these both phosphors retained 95 % of their initial luminescence intensity, demonstrating excellent thermal stability. Notably, the fabricated w-LEDs devices with the as-prepared green phosphors emitted a bright warm white light, which showing excellent colorimetric parameters of CCT = 4596 K and Ra = 89.2. The color gamut of fitted LCD reaches 75.16 % of the National Television System Committee (NTSC) standard. The results indicate that the NaLa0.82Si0.96B0.04O3.96F0.04:0.18Tb3+ and NaLa0.78Ba0.04SiO3.96F0.04:0.18Tb3+ green-emitting phosphors have great potential in the applications of LCD backlight and solid-state lighting.
{"title":"The luminescence enhancement of NaLaSiO4:Tb3+ green phosphor by co-substituting Si4+-O2-/La3+-O2- with B3+-F-/Ba2+-F- for white light-emitting diodes","authors":"Xianzhu Zhou , Wentao Zhang , Zhou Zhao , Peicong Zhang , Ning Sun , Xiangkui Cheng","doi":"10.1016/j.ceramint.2025.01.122","DOIUrl":"10.1016/j.ceramint.2025.01.122","url":null,"abstract":"<div><div>Based on the green emission of NaLa<sub>0.82</sub>SiO<sub>4</sub>:0.18Tb<sup>3+</sup> phosphor, the luminescence properties including intensity and stability of phosphor was effectively improved via the isomorphic substitution of crystal groups including [B<sup>3+</sup>-F<sup>-</sup>]→[Si<sup>4+</sup>-O<sup>2-</sup>] and [Ba<sup>2+</sup>-F<sup>-</sup>]→[La<sup>3+</sup>-O<sup>2-</sup>]. The luminescence intensities (λ<sub>em</sub> = 544 nm) of NaLa<sub>0.82</sub>Si<sub>0.96</sub>B<sub>0.04</sub>O<sub>3.96</sub>F<sub>0.04</sub>:0.18Tb<sup>3+</sup> and NaLa<sub>0.78</sub>Ba<sub>0.04</sub>SiO<sub>3.96</sub>F<sub>0.04</sub>:0.18Tb<sup>3+</sup> increased to 4.22 times and 5.49 times that of NaLa<sub>0.82</sub>SiO<sub>4</sub>:0.18Tb<sup>3+</sup>, respectively. Moreover, even at an operating temperature of 423 K, these both phosphors retained 95 % of their initial luminescence intensity, demonstrating excellent thermal stability. Notably, the fabricated <em>w</em>-LEDs devices with the as-prepared green phosphors emitted a bright warm white light, which showing excellent colorimetric parameters of CCT = 4596 K and Ra = 89.2. The color gamut of fitted LCD reaches 75.16 % of the National Television System Committee (NTSC) standard. The results indicate that the NaLa<sub>0.82</sub>Si<sub>0.96</sub>B<sub>0.04</sub>O<sub>3.96</sub>F<sub>0.04</sub>:0.18Tb<sup>3+</sup> and NaLa<sub>0.78</sub>Ba<sub>0.04</sub>SiO<sub>3.96</sub>F<sub>0.04</sub>:0.18Tb<sup>3+</sup> green-emitting phosphors have great potential in the applications of LCD backlight and solid-state lighting.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 12831-12841"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814936","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 : 2025-04-01DOI: 10.1016/j.ceramint.2025.01.097
Hao Sui , Jianshan Zhou , Jinye Niu , Ziheng Cui , Jingjing Gao , Yansong Zhao , Feibiao Liu , Yun Wu , Zhe Peng
The Cf/SiBCN-ZrB2 composites were prepared using an inorganic synthesis method - hot press reactive sintering. Three distinct composites were fabricated by combining reactive sintering with high-temperature melt infiltration, with the raw material ratios adjusted accordingly. A long-term ablation test lasting 400 s was performed using an oxy-acetylene flame, the surface temperatures of the samples exceeded 2100 °C. The absence of macroscopic cracks in all three samples indicates that the SiBCN composites, prepared via reactive sintering, exhibit excellent high-temperature stability. Among these, the composites with a higher silicon content, demonstrated the lowest ablation loss rate, with linear and mass ablation rates of 0.205 μm/s and 1.11 mg/s, respectively, significantly outperforming the composites with a reduced silicon content. The surface of the ablated samples, the continuous and dense ZrO2-SiO2 oxide layer, which serves as the main ablation barrier, effectively isolates the matrix from the oxy-acetylene flame.
{"title":"Preparation and long-term ablation resistance of reaction-sintered Cf/SiBCN (Zr) composites","authors":"Hao Sui , Jianshan Zhou , Jinye Niu , Ziheng Cui , Jingjing Gao , Yansong Zhao , Feibiao Liu , Yun Wu , Zhe Peng","doi":"10.1016/j.ceramint.2025.01.097","DOIUrl":"10.1016/j.ceramint.2025.01.097","url":null,"abstract":"<div><div>The C<sub>f</sub>/SiBCN-ZrB<sub>2</sub> composites were prepared using an inorganic synthesis method - hot press reactive sintering. Three distinct composites were fabricated by combining reactive sintering with high-temperature melt infiltration, with the raw material ratios adjusted accordingly. A long-term ablation test lasting 400 s was performed using an oxy-acetylene flame, the surface temperatures of the samples exceeded 2100 °C. The absence of macroscopic cracks in all three samples indicates that the SiBCN composites, prepared via reactive sintering, exhibit excellent high-temperature stability. Among these, the composites with a higher silicon content, demonstrated the lowest ablation loss rate, with linear and mass ablation rates of 0.205 μm/s and 1.11 mg/s, respectively, significantly outperforming the composites with a reduced silicon content. The surface of the ablated samples, the continuous and dense ZrO<sub>2</sub>-SiO<sub>2</sub> oxide layer, which serves as the main ablation barrier, effectively isolates the matrix from the oxy-acetylene flame.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 12563-12576"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814952","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 : 2025-04-01DOI: 10.1016/j.ceramint.2024.12.544
Wei Gao, Jinglei Zhang, Lin Shao, Jiaxi Li, Peng Ding, Qingyan Han, Xuewen Yan, Chenyun Zhang, Jun Dong
Enhancing upconversion luminescence in rare-earth materials through the plasmonic effects of precious metals has emerged as a highly effective strategy. In this study, we explore three distinct self-assembly techniques to fabricate alloy nano-film substrates using silver-coated gold (Au@Ag) core-shell nanoparticles, each with unique structural attributes. To enhance the upconversion luminescence of Er3+ ions, we combine these substrates with NaYF4:Yb3+/Er3+ nanoparticles, creating NaYF4:Yb3+/Er3+/Au@Ag composite nanostructures. The upconversion emission of Er3+ ions is observably boosted when directly combined with Au@Ag nano-films of various structures under a 980 nm laser excitation. Surprisingly, incorporating a NaYF4 inert shell as an isolating layer results in a remarkable 13.7-fold enhancement of upconversion luminescence in the NaYF4:Yb3+/Er3+@NaYF4/Au@Ag composite structure relative to isolated NaYF4: Yb3+/Er3+ nanoparticles. The enhancement mechanism was carefully discussed based on spectral characteristics and luminous lifetime. It was found that the enhanced upconversion emission of nanoparticles on differently structured substrates is primarily driven by excitation enhancement. The composite rare-earth and metal nanoparticle structures fabricated in this investigation not only effectively enhance material spectral properties effectively but also streamline the process by employing an inert NaYF4 shell as an isolation layer. This novel approach offers a promising avenue for developing efficient luminescent material systems.
{"title":"Enhancing upconversion luminescence of Er3+ ions In NaYF4:Yb3+/Er3+/Au@Ag composite nanostructures","authors":"Wei Gao, Jinglei Zhang, Lin Shao, Jiaxi Li, Peng Ding, Qingyan Han, Xuewen Yan, Chenyun Zhang, Jun Dong","doi":"10.1016/j.ceramint.2024.12.544","DOIUrl":"10.1016/j.ceramint.2024.12.544","url":null,"abstract":"<div><div>Enhancing upconversion luminescence in rare-earth materials through the plasmonic effects of precious metals has emerged as a highly effective strategy. In this study, we explore three distinct self-assembly techniques to fabricate alloy nano-film substrates using silver-coated gold (Au@Ag) core-shell nanoparticles, each with unique structural attributes. To enhance the upconversion luminescence of Er<sup>3+</sup> ions, we combine these substrates with NaYF<sub>4</sub>:Yb<sup>3+</sup>/Er<sup>3+</sup> nanoparticles, creating NaYF<sub>4</sub>:Yb<sup>3+</sup>/Er<sup>3+</sup>/Au@Ag composite nanostructures. The upconversion emission of Er<sup>3+</sup> ions is observably boosted when directly combined with Au@Ag nano-films of various structures under a 980 nm laser excitation. Surprisingly, incorporating a NaYF<sub>4</sub> inert shell as an isolating layer results in a remarkable 13.7-fold enhancement of upconversion luminescence in the NaYF<sub>4</sub>:Yb<sup>3+</sup>/Er<sup>3+</sup>@NaYF<sub>4</sub>/Au@Ag composite structure relative to isolated NaYF<sub>4</sub>: Yb<sup>3+</sup>/Er<sup>3+</sup> nanoparticles. The enhancement mechanism was carefully discussed based on spectral characteristics and luminous lifetime. It was found that the enhanced upconversion emission of nanoparticles on differently structured substrates is primarily driven by excitation enhancement. The composite rare-earth and metal nanoparticle structures fabricated in this investigation not only effectively enhance material spectral properties effectively but also streamline the process by employing an inert NaYF<sub>4</sub> shell as an isolation layer. This novel approach offers a promising avenue for developing efficient luminescent material systems.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11277-11285"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815059","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 : 2025-04-01DOI: 10.1016/j.ceramint.2025.01.048
Wenxia Li , Ruihan Liang , Jipeng Rao , Xiaoyun Mi , Xiuling Liu
Based on crystal field theory and inspired by advancements in photovoltaic catalysis, a series of luminescent materials, K2NaIn0.88-xF6: 0.1Cr3+, 0.02Mn4+, xAl3+ (x = 0.015–0.035), were synthesized via the hydrothermal method. Compared to the K2NaIn0.88F6: 0.1Cr3+, 0.02Mn4+ phosphor, the introduction of Al3+ led to a substantial enhancement in luminescence properties: the luminescence intensity increased by 1.73 times, and the quantum yield (QY) rose from 36.8 % to 59.2 %. To uncover the mechanism behind this improvement, first-principles calculations were performed to analyze changes in the band gap and density of states of the K2NaInF6 host upon Al3+ doping. These studies provided detailed insights into the root cause of the luminescence enhancement following the partial substitution of In3+ by Al3+. Additionally, the doped samples demonstrated improved resistance to thermal quenching. At 423 K (150 °C), the luminescence intensity retained 80.46 % of its value at room temperature, representing an approximate 5 % increase in thermal stability. This was further supported by calculations of the Debye temperature and activation energy. In conclusion, a device featuring NIR pc-LED was created utilizing the NIR phosphor that was synthesized. When operating at a current of 350 mA, the NIR output power attained 190.58 mW; while at a lower current of 50 mA, the device achieved an electrical conversion efficiency of 15.4 %. Additionally, the material was effectively utilized for biological imaging and night-vision purposes, producing promising results.
{"title":"A cationic substitution strategy was employed to synthesize phosphor K2NaIn1-xAlxF6: Cr3+, Mn4+ with enhanced optical properties and thermal stability","authors":"Wenxia Li , Ruihan Liang , Jipeng Rao , Xiaoyun Mi , Xiuling Liu","doi":"10.1016/j.ceramint.2025.01.048","DOIUrl":"10.1016/j.ceramint.2025.01.048","url":null,"abstract":"<div><div>Based on crystal field theory and inspired by advancements in photovoltaic catalysis, a series of luminescent materials, K<sub>2</sub>NaIn<sub>0.88-x</sub>F<sub>6</sub>: 0.1Cr<sup>3+</sup>, 0.02Mn<sup>4+</sup>, xAl<sup>3+</sup> (x = 0.015–0.035), were synthesized via the hydrothermal method. Compared to the K<sub>2</sub>NaIn<sub>0.88</sub>F<sub>6</sub>: 0.1Cr<sup>3+</sup>, 0.02Mn<sup>4+</sup> phosphor, the introduction of Al<sup>3+</sup> led to a substantial enhancement in luminescence properties: the luminescence intensity increased by 1.73 times, and the quantum yield (QY) rose from 36.8 % to 59.2 %. To uncover the mechanism behind this improvement, first-principles calculations were performed to analyze changes in the band gap and density of states of the K<sub>2</sub>NaInF<sub>6</sub> host upon Al<sup>3+</sup> doping. These studies provided detailed insights into the root cause of the luminescence enhancement following the partial substitution of In<sup>3+</sup> by Al<sup>3+</sup>. Additionally, the doped samples demonstrated improved resistance to thermal quenching. At 423 K (150 °C), the luminescence intensity retained 80.46 % of its value at room temperature, representing an approximate 5 % increase in thermal stability. This was further supported by calculations of the Debye temperature and activation energy. In conclusion, a device featuring NIR pc-LED was created utilizing the NIR phosphor that was synthesized. When operating at a current of 350 mA, the NIR output power attained 190.58 mW; while at a lower current of 50 mA, the device achieved an electrical conversion efficiency of 15.4 %. Additionally, the material was effectively utilized for biological imaging and night-vision purposes, producing promising results.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11961-11973"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815073","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 : 2025-04-01DOI: 10.1016/j.ceramint.2025.01.160
Guofu Lian , Jiangbin Chen , Hua Lu , Changrong Chen , Xu Huang
Laser cladding was used to fabricate in-situ synthesized xNbC, enhancing the Ni-20 W C coating on AISI1045 steel. The study examined the effects of NbC synthesis on the microstructure, microhardness, tribological properties, and corrosion resistance of metal-matrix composite (MMC) coatings. No significant changes were observed in phase composition with increasing NbC synthesis. As x increased, structural changes included NbC particle agglomeration, roughening, FCC phase density variations, and WCp nucleation. At x = 20 wt%, the structure was optimally refined with even distribution. The nucleation of WCp gradually changed from granular grain boundary segregation to heterogeneous nucleation close to NbC. Thermodynamic calculations revealed a gradient-layered structure at the WCp-NbC interface. The microhardness peaked at 57.63 HRC with 20 wt% NbC, approximately 3.6 times the matrix hardness. The coatings exhibited abrasive, adhesive, and oxidative wear. The coating exhibits the best corrosion resistance at x = 20 wt%. The results provide a theoretical basis for high-performance MMC coatings via laser cladding.
{"title":"The microstructure and properties of reinforced Ni-20WC coatings by the laser-cladding in-situ synthesis of xNbC","authors":"Guofu Lian , Jiangbin Chen , Hua Lu , Changrong Chen , Xu Huang","doi":"10.1016/j.ceramint.2025.01.160","DOIUrl":"10.1016/j.ceramint.2025.01.160","url":null,"abstract":"<div><div>Laser cladding was used to fabricate in-situ synthesized xNbC, enhancing the Ni-20 W C coating on AISI1045 steel. The study examined the effects of NbC synthesis on the microstructure, microhardness, tribological properties, and corrosion resistance of metal-matrix composite (MMC) coatings. No significant changes were observed in phase composition with increasing NbC synthesis. As x increased, structural changes included NbC particle agglomeration, roughening, FCC phase density variations, and WCp nucleation. At x = 20 wt%, the structure was optimally refined with even distribution. The nucleation of WCp gradually changed from granular grain boundary segregation to heterogeneous nucleation close to NbC. Thermodynamic calculations revealed a gradient-layered structure at the WCp-NbC interface. The microhardness peaked at 57.63 HRC with 20 wt% NbC, approximately 3.6 times the matrix hardness. The coatings exhibited abrasive, adhesive, and oxidative wear. The coating exhibits the best corrosion resistance at x = 20 wt%. The results provide a theoretical basis for high-performance MMC coatings via laser cladding.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 13135-13151"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815179","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 : 2025-04-01DOI: 10.1016/j.ceramint.2024.12.524
N.F. Dantas, F.W.S. Rodrigues, M.N. Queiroz, F. Pedrochi, A. Steimacher
In this work, a series of borate glasses with the composition (40-x)K2O-xSrO-60B2O3 (BKSr), with x = 10, 20 and 30 mol% were synthesized by melt-quenching technique, and their structural, thermal and spectroscopic properties, along with a molecular dynamics study, were discussed as a function of the replacement of K2O with SrO. The amorphous nature of all samples was confirmed by X-Ray Diffraction (XRD) and the physical properties such as density and molar volume indicated that the replacement promotes a greater packing and polymerization of the glass network. Fourier-Transform Infrared (FTIR) analysis revealed the structural changes in glass network as a function of SrO content, indicating BO3 conversion into BO4 units, which were confirmed by tetracoordinated boron fraction (N4). Based on the absorption coefficients, the glasses were found to exhibit broad transparency across the UV to NIR regions (350–2500 nm). Molecular dynamics simulations were employed to obtain information about the glass microstructure and to compare it with experimental data. The results indicate that all glasses presented good properties to be applied in optical devices.
{"title":"Experimental and molecular dynamics analyses of the replacement of K₂O by SrO on the structural, thermal, and spectroscopic properties of K₂O-SrO-B₂O₃ glasses","authors":"N.F. Dantas, F.W.S. Rodrigues, M.N. Queiroz, F. Pedrochi, A. Steimacher","doi":"10.1016/j.ceramint.2024.12.524","DOIUrl":"10.1016/j.ceramint.2024.12.524","url":null,"abstract":"<div><div>In this work, a series of borate glasses with the composition (40-x)K<sub>2</sub>O-xSrO-60B<sub>2</sub>O<sub>3</sub> (BKSr), with x = 10, 20 and 30 mol% were synthesized by melt-quenching technique, and their structural, thermal and spectroscopic properties, along with a molecular dynamics study, were discussed as a function of the replacement of K<sub>2</sub>O with SrO. The amorphous nature of all samples was confirmed by X-Ray Diffraction (XRD) and the physical properties such as density and molar volume indicated that the replacement promotes a greater packing and polymerization of the glass network. Fourier-Transform Infrared (FTIR) analysis revealed the structural changes in glass network as a function of SrO content, indicating BO<sub>3</sub> conversion into BO<sub>4</sub> units, which were confirmed by tetracoordinated boron fraction (N<sub>4</sub>). Based on the absorption coefficients, the glasses were found to exhibit broad transparency across the UV to NIR regions (350–2500 nm). Molecular dynamics simulations were employed to obtain information about the glass microstructure and to compare it with experimental data. The results indicate that all glasses presented good properties to be applied in optical devices.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11048-11058"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815235","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 : 2025-04-01DOI: 10.1016/j.ceramint.2024.12.327
Xiang Guo, Jinshuo Qiao, Zhenhua Wang, Wang Sun, Kening Sun
This study investigated the effects of patameters of phase inversion tape casting process on the skin-layer and finger-like layer structures of anode of solid oxide fuel cells (SOFCs). The skin-layer structure of anode was studied by controlling the slurry immersion approach during the phase inversion process. Consequently, the anode body with a smooth surface could be obtained when the slurry was immersed in deionized water with a constant speed, via tilted approach. Furthermore, the effects of solid content and polymer concentration on the anode structure were comprehensively studied. With the increase in solid content, the porosity and the size of channels gradually decreased. By contrast, the wall thickness of channel gradually increasesed. The anode with finger-like structure, prepared with a solid content of 65 wt% and polymer concentration of 25 wt%, exhibited the best suitable structure for gas diffusion, which is conducive to developing SOFCs based on finger-like structure.
{"title":"Regulation of parameters for phase inversion tape casting technology applied in solid oxide fuel cells","authors":"Xiang Guo, Jinshuo Qiao, Zhenhua Wang, Wang Sun, Kening Sun","doi":"10.1016/j.ceramint.2024.12.327","DOIUrl":"10.1016/j.ceramint.2024.12.327","url":null,"abstract":"<div><div>This study investigated the effects of patameters of phase inversion tape casting process on the skin-layer and finger-like layer structures of anode of solid oxide fuel cells (SOFCs). The skin-layer structure of anode was studied by controlling the slurry immersion approach during the phase inversion process. Consequently, the anode body with a smooth surface could be obtained when the slurry was immersed in deionized water with a constant speed, via tilted approach. Furthermore, the effects of solid content and polymer concentration on the anode structure were comprehensively studied. With the increase in solid content, the porosity and the size of channels gradually decreased. By contrast, the wall thickness of channel gradually increasesed. The anode with finger-like structure, prepared with a solid content of 65 wt% and polymer concentration of 25 wt%, exhibited the best suitable structure for gas diffusion, which is conducive to developing SOFCs based on finger-like structure.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 10998-11005"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815348","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 : 2025-04-01DOI: 10.1016/j.ceramint.2025.01.180
Paula M. Riosalido , Pablo Velásquez , Ángel Murciano , Piedad N. De Aza
In this investigation, three distinct multiphasic scaffolds, comprising primary crystalline phases of SiO₂, Ca₂P₂O₇, and Ca₃(PO₄)₂, were developed. These scaffolds feature surface coatings that have been functionalised with Na, K, and varying molar proportions of Mg (0–1%). The samples were extensively characterised to evaluate a number of key properties including microstructure, porosity, mechanical properties, biodegradation profile, biocompatibility and in vitro bioactivity. The scaffolds demonstrated a mechanical strength of 1.8 MPa, accompanied by a high macroporosity of over 85 % and micropores ranging from 200 to 6 μm. All scaffolds showed bioactivity. Notably, CS0.7 Mg exhibited a distinctive topography characterised by non-periodic, irregular lamellae at both the micro- and nanoscale. During the bioactivity assays, the lamellae were progressively covered by HA until they were completely obscured after 14 days in SBF. This bioactive behaviour was accompanied by gradual degradation in PBS, with a 15 % weight loss over 21 days, indicating suitability for bone regeneration. In addition, ICP-OES analysis demonstrated ionic exchange from the scaffolds into the culture medium at both concentrations of 15 mg/mL and 30 mg/mL, which promoted the proliferation of 3T3 fibroblasts. Cells seeded on the CS0.7 Mg scaffold also showed sustained cell proliferation over time. This proliferation was found to be influenced by the topography of the scaffold, with the greatest enhancement observed in the CS0.7 Mg-7D samples, which had HA-covered lamellae.
{"title":"Multilayer scaffolds designed with bioinspired topography for bone regeneration","authors":"Paula M. Riosalido , Pablo Velásquez , Ángel Murciano , Piedad N. De Aza","doi":"10.1016/j.ceramint.2025.01.180","DOIUrl":"10.1016/j.ceramint.2025.01.180","url":null,"abstract":"<div><div>In this investigation, three distinct multiphasic scaffolds, comprising primary crystalline phases of SiO₂, Ca₂P₂O₇, and Ca₃(PO₄)₂, were developed. These scaffolds feature surface coatings that have been functionalised with Na, K, and varying molar proportions of Mg (0–1%). The samples were extensively characterised to evaluate a number of key properties including microstructure, porosity, mechanical properties, biodegradation profile, biocompatibility and <em>in vitro</em> bioactivity. The scaffolds demonstrated a mechanical strength of 1.8 MPa, accompanied by a high macroporosity of over 85 % and micropores ranging from 200 to 6 μm. All scaffolds showed bioactivity. Notably, CS0.7 Mg exhibited a distinctive topography characterised by non-periodic, irregular lamellae at both the micro- and nanoscale. During the bioactivity assays, the lamellae were progressively covered by HA until they were completely obscured after 14 days in SBF. This bioactive behaviour was accompanied by gradual degradation in PBS, with a 15 % weight loss over 21 days, indicating suitability for bone regeneration. In addition, ICP-OES analysis demonstrated ionic exchange from the scaffolds into the culture medium at both concentrations of 15 mg/mL and 30 mg/mL, which promoted the proliferation of 3T3 fibroblasts. Cells seeded on the CS0.7 Mg scaffold also showed sustained cell proliferation over time. This proliferation was found to be influenced by the topography of the scaffold, with the greatest enhancement observed in the CS0.7 Mg-7D samples, which had HA-covered lamellae.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 13363-13373"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815559","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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