Pub Date : 2025-03-01DOI: 10.1016/j.ceramint.2024.12.320
Haiding Zhong , Zhiao Han , Jinde Ling , Genglu Li , Yinyu Chen , Zhen Wang , Changhong Wang , De Li , Xiaoyu Wang
The development of electrochromic materials with high optical modulation and good cycling stability is a key focus in dual-band electrochromism. Hydrated tungsten oxide exhibits dynamic and independent control over the near-infrared and visible transmittance within the solar spectrum, garnering widespread attention in electrochromic applications. However, its optical modulation and cycling stability need further enhancement due to limited ion diffusion kinetics. Herein, a simple photo-deposition method is developed for synthesizing mesoporous WO3·H2O films, characterized by high porosity and large surface area, which facilitates ion and electron transport within the films. Experimental results show that mesoporous WO3·H2O can achieve three functional modes under different voltages: “bright”, “cold”, and “dark”. Compared to WO3·H2O nanoplates, mesoporous WO3·H2O electrode enables a superior dual-band electrochromic performance, including high optical modulation (74.1 % at 700 nm and 65.9 % at 1150 nm), rapid response times (13.5 s for coloring and 11.5 s for bleaching), high coloring efficiencies (138.9 cm2/C), and excellent cycling stability (optical modulation retention rate of 88.2 % after 1000 cycles). This research provides a novel approach to enhancing dual-band electrochromic performance through the incorporation of mesoporosity in materials.
{"title":"Enhanced dual-band electrochromism in mesoporous WO3·H2O with high optical modulation and stability","authors":"Haiding Zhong , Zhiao Han , Jinde Ling , Genglu Li , Yinyu Chen , Zhen Wang , Changhong Wang , De Li , Xiaoyu Wang","doi":"10.1016/j.ceramint.2024.12.320","DOIUrl":"10.1016/j.ceramint.2024.12.320","url":null,"abstract":"<div><div>The development of electrochromic materials with high optical modulation and good cycling stability is a key focus in dual-band electrochromism. Hydrated tungsten oxide exhibits dynamic and independent control over the near-infrared and visible transmittance within the solar spectrum, garnering widespread attention in electrochromic applications. However, its optical modulation and cycling stability need further enhancement due to limited ion diffusion kinetics. Herein, a simple photo-deposition method is developed for synthesizing mesoporous WO<sub>3</sub>·H<sub>2</sub>O films, characterized by high porosity and large surface area, which facilitates ion and electron transport within the films. Experimental results show that mesoporous WO<sub>3</sub>·H<sub>2</sub>O can achieve three functional modes under different voltages: “bright”, “cold”, and “dark”. Compared to WO<sub>3</sub>·H<sub>2</sub>O nanoplates, mesoporous WO<sub>3</sub>·H<sub>2</sub>O electrode enables a superior dual-band electrochromic performance, including high optical modulation (74.1 % at 700 nm and 65.9 % at 1150 nm), rapid response times (13.5 s for coloring and 11.5 s for bleaching), high coloring efficiencies (138.9 cm<sup>2</sup>/C), and excellent cycling stability (optical modulation retention rate of 88.2 % after 1000 cycles). This research provides a novel approach to enhancing dual-band electrochromic performance through the incorporation of mesoporosity in materials.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 8897-8903"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512230","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 microstructures, leakage conduction and energy storage performances of Gadolinium (Gd3+) modified barium calcium zirconate titanate based thin films [Ba(0.85-x)Ca0.15Gdx][Zr0.2Ti0.8]O(3+0.5x) (x = 0, 0.005, 0.0075 and 0.01) prepared on the Pt/Ti/SiO2/Si substrates using sol-gel method were characterized and analyzed. The dense and uniform microstructure with fine nanocrystalline grains is obtained in low Gd3+ concentration (x ≤ 0.0075) doped BCGZT thin films with single phase perovskite structure. With the increase of Gd3+ content, the leakage current density of BCGZT films initially decreases to the minimum at x = 0.0075 due to the existing of defect dipoles VCa″-VO•• caused by the Gd3+ substitution for A site ions and then increases significantly due to the appearance of impurity phases. With the increase of electric field, the leakage mechanism for each BCGZT film transforms from ohmic conduction and/or SCL conduction to F-N tunneling. The remanent polarization keeps decreasing because of the weakened ferroelectricity of Gd3+ modified BCZT perovskites and the decreasing average grain size as the Gd3+ content increases. The BCGZT thin film with x = 0.0075 possesses an enhanced energy storage density of 55.1 J/cm3 and an acceptable energy storage efficiency of 67.1 % at the ultra-high breakdown field of 4300 kV/cm, which is promising for capacitor applications.
{"title":"Effects of gadolinium modification on leakage conduction and energy storage performance of sol-gel derived (Ba0.85Ca0.15)(Zr0.2Ti0.8)O3 thin films","authors":"Ke Zhang, Chen Zhang, Haoliang Li, Jingwang Lu, Zhipeng Ma, Xing Zhang","doi":"10.1016/j.ceramint.2024.12.360","DOIUrl":"10.1016/j.ceramint.2024.12.360","url":null,"abstract":"<div><div>The microstructures, leakage conduction and energy storage performances of Gadolinium (Gd<sup>3+</sup>) modified barium calcium zirconate titanate based thin films [Ba<sub>(0.85-x)</sub>Ca<sub>0.15</sub>Gd<sub>x</sub>][Zr<sub>0.2</sub>Ti<sub>0.8</sub>]O<sub>(3+0.5x)</sub> (<em>x</em> = 0, 0.005, 0.0075 and 0.01) prepared on the Pt/Ti/SiO<sub>2</sub>/Si substrates using sol-gel method were characterized and analyzed. The dense and uniform microstructure with fine nanocrystalline grains is obtained in low Gd<sup>3+</sup> concentration (<em>x</em> ≤ 0.0075) doped BCGZT thin films with single phase perovskite structure. With the increase of Gd<sup>3+</sup> content, the leakage current density of BCGZT films initially decreases to the minimum at <em>x</em> = 0.0075 due to the existing of defect dipoles V<sub>Ca</sub>″-V<sub>O</sub><sup>••</sup> caused by the Gd<sup>3+</sup> substitution for A site ions and then increases significantly due to the appearance of impurity phases. With the increase of electric field, the leakage mechanism for each BCGZT film transforms from ohmic conduction and/or SCL conduction to F-N tunneling. The remanent polarization keeps decreasing because of the weakened ferroelectricity of Gd<sup>3+</sup> modified BCZT perovskites and the decreasing average grain size as the Gd<sup>3+</sup> content increases. The BCGZT thin film with <em>x</em> = 0.0075 possesses an enhanced energy storage density of 55.1 J/cm<sup>3</sup> and an acceptable energy storage efficiency of 67.1 % at the ultra-high breakdown field of 4300 kV/cm, which is promising for capacitor applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 9248-9256"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512254","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 : 2025-03-01DOI: 10.1016/j.ceramint.2024.12.330
Chenxin Li , Yong Liu , Kan Wang , Yipeng Qin , Xiaotong Wu
3D printed reaction-bonded silicon carbide (RBSiC) is widely employed across various industries due to its complex geometries and exceptional properties. However, its precise machining remains a significant challenge. Electrochemical grinding (ECG) presents a promising solution for the precise machining of RBSiC. Still, further optimization of the process is still required. In this study, we investigate the electrochemical oxidation and corrosion behavior of 3D printed RBSiC in an eco-friendly KH2PO4 electrolyte, characterize its microstructure and phases composition, and developed a predictive model for the thickness of the oxidation layer. Experimental results show that the oxidation process of RBSiC, influenced by free silicon, is intricate and segmented, involving the oxidation of Si and SiC as well as Si over-passivation under high voltage. SEM reveals that the oxide film thickness ranges from 1.57 μm to 15.5 μm. EIS and microstructural analysis identify micro defects filled with electrolyte in the oxide layer at high voltage, causing the dielectric constant to surge to 19.65—a nearly 500 % increase. Thus, this study calibrates oxidation current efficiency (η) and the real dielectric constant () of RBSiC in KH2PO4 electrolyte, leading to the development of a three-stage predictive model that matching with the observed oxide film growth trends. These findings provide a theoretical framework and empirical data for optimizing ECG processing of RBSiC.
{"title":"Electrochemical oxidation and corrosion behavior of 3D printed reaction-bonded silicon carbide ceramics in eco-friendly electrolyte","authors":"Chenxin Li , Yong Liu , Kan Wang , Yipeng Qin , Xiaotong Wu","doi":"10.1016/j.ceramint.2024.12.330","DOIUrl":"10.1016/j.ceramint.2024.12.330","url":null,"abstract":"<div><div>3D printed reaction-bonded silicon carbide (RBSiC) is widely employed across various industries due to its complex geometries and exceptional properties. However, its precise machining remains a significant challenge. Electrochemical grinding (ECG) presents a promising solution for the precise machining of RBSiC. Still, further optimization of the process is still required. In this study, we investigate the electrochemical oxidation and corrosion behavior of 3D printed RBSiC in an eco-friendly KH<sub>2</sub>PO<sub>4</sub> electrolyte, characterize its microstructure and phases composition, and developed a predictive model for the thickness of the oxidation layer. Experimental results show that the oxidation process of RBSiC, influenced by free silicon, is intricate and segmented, involving the oxidation of Si and SiC as well as Si over-passivation under high voltage. SEM reveals that the oxide film thickness ranges from 1.57 μm to 15.5 μm. EIS and microstructural analysis identify micro defects filled with electrolyte in the oxide layer at high voltage, causing the dielectric constant to surge to 19.65—a nearly 500 % increase. Thus, this study calibrates oxidation current efficiency (η) and the real dielectric constant (<span><math><mrow><msub><mi>ε</mi><mrow><mi>r</mi><mi>a</mi></mrow></msub></mrow></math></span>) of RBSiC in KH<sub>2</sub>PO<sub>4</sub> electrolyte, leading to the development of a three-stage predictive model that matching with the observed oxide film growth trends. These findings provide a theoretical framework and empirical data for optimizing ECG processing of RBSiC.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 8997-9011"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512107","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 : 2025-03-01DOI: 10.1016/j.ceramint.2024.12.353
Y.Q. Guo , Aditya Jain , H.Z. Zhou , Y.G. Wang
High entropy dielectric ceramics with excellent relaxation characteristics are ideal materials for pulse capacitors. In this study, a high entropy dielectric ceramic based on NaNbO3 was engineered to enhance relaxation properties through non-equivalent ion substitution and increased entropy. The composition studied was (1-x)(Na0.5Li0.5NbO3) - x(Sr0.5Bi0.5)(Fe0.5Ti0.25Zr0.25)O3 (NLN-SBFTZ) with x = 0, 0.15, 0.20, and 0.25. The introduction of non-equivalent ions (Sr0.5Bi0.5)5/2+ and (Fe0.5Ti0.25Zr0.25)7/2+, significantly increases the configurational entropy (ΔSconfig). With a breakdown field strength of 500 kV/cm, the modified ceramics sample (x = 0.20) shows a recoverable energy density (Wrec) of 4.70 J/cm3 and an energy efficiency (η) of 83.5 %, surpassing the performance of undoped samples (Wrec = 0.15 J/cm3, η = 43.2 %). These results confirm that the high entropy design strategy via non-equivalent ion doping effectively enhances the energy storage capabilities of lead-free dielectric materials.
{"title":"Enhanced energy storage performance of high entropy (1-x)(Na0.5Li0.5NbO3)-x(Sr0.5Bi0.5)(Fe0.5Ti0.25Zr0.25)O3 dielectric ceramics through non-equivalent ion doping","authors":"Y.Q. Guo , Aditya Jain , H.Z. Zhou , Y.G. Wang","doi":"10.1016/j.ceramint.2024.12.353","DOIUrl":"10.1016/j.ceramint.2024.12.353","url":null,"abstract":"<div><div>High entropy dielectric ceramics with excellent relaxation characteristics are ideal materials for pulse capacitors. In this study, a high entropy dielectric ceramic based on NaNbO<sub>3</sub> was engineered to enhance relaxation properties through non-equivalent ion substitution and increased entropy. The composition studied was (1-<em>x</em>)(Na<sub>0.5</sub>Li<sub>0.5</sub>NbO<sub>3</sub>) - <em>x</em>(Sr<sub>0.5</sub>Bi<sub>0.5</sub>)(Fe<sub>0.5</sub>Ti<sub>0.25</sub>Zr<sub>0.25</sub>)O<sub>3</sub> (NLN-SBFTZ) with <em>x</em> = 0, 0.15, 0.20, and 0.25. The introduction of non-equivalent ions (Sr<sub>0.5</sub>Bi<sub>0.5</sub>)<sup>5/2+</sup> and (Fe<sub>0.5</sub>Ti<sub>0.25</sub>Zr<sub>0.25</sub>)<sup>7/2+</sup>, significantly increases the configurational entropy (Δ<em>S</em><sub>config</sub>). With a breakdown field strength of 500 kV/cm, the modified ceramics sample (<em>x</em> = 0.20) shows a recoverable energy density (<em>W</em><sub><em>rec</em></sub>) of 4.70 J/cm<sup>3</sup> and an energy efficiency (<em>η</em>) of 83.5 %, surpassing the performance of undoped samples (<em>W</em><sub><em>rec</em></sub> = 0.15 J/cm<sup>3</sup>, <em>η</em> = 43.2 %). These results confirm that the high entropy design strategy via non-equivalent ion doping effectively enhances the energy storage capabilities of lead-free dielectric materials.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 9199-9208"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510847","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 present experimental report articulates a comprehensive investigation on the synthesis, structural, and photoluminescence characteristics of M0.05,Eu0.05:Y0.90VO4 (M = Li+, Na+, K+) nanophosphors synthesised by auto-combustion approach, for optical display and anticounterfeiting technologies. Various characterization tools such as X-ray diffractometer (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Fourier transform infra-red (FTIR) Spectroscope, and Raman spectroscope have been employed to understand the morphology and crystal structure of M0.05,Eu0.05:Y0.90VO4 (M = Li+, Na+, K+) nanophosphor, which reveals the formation of a pure tetragonal structure and well crystalline phase. Moreover, the UV–Vis spectra, suggests that the as-synthesised material substantiated to possess an energy band gap of ∼3.6 eV conjecturing it as a wide-band material, and the refractive index (n) of the prepared samples has been deduced as ∼ 2.1. Among all alkali ions, Li+-codoped sample exhibits the most intense PL spectra. The enhancement in PL intensity has been observed due to the energy transfer of VO43−→Eu3+ and the codoping of lithium ions acts as a good charge compensator. For the optimized sample CIE coordinates has been found as (0.59, 0.39) and CCT value as 1712 K, which suggest it as a prospective candidate for the warm LEDs. The optimized sample has further been investigated for the visualization of Latent fingerprint on glass slide and as security ink. It displays efficient applicability as a well-defined ridge features up to level III. Henceforth, the as-synthesised Li0.05,Eu0.05:Y0.90VO4 nanophosphor may potentially be applied for multipurpose applications.
{"title":"Alkali metal ion codoped Eu3+ activated yttrium orthovanadate with tunable photoluminescence properties for LEDs and anti-counterfeiting applications","authors":"Anuradha , Arpita Dwivedi , Satyam Upadhyay , Amit Srivastava , Monika Srivastava , Rajneesh Kumar , S.K. Srivastava","doi":"10.1016/j.ceramint.2024.12.310","DOIUrl":"10.1016/j.ceramint.2024.12.310","url":null,"abstract":"<div><div>The present experimental report articulates a comprehensive investigation on the synthesis, structural, and photoluminescence characteristics of M<sub>0.05</sub>,Eu<sub>0.05</sub>:Y<sub>0.90</sub>VO<sub>4</sub> (M = Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>) nanophosphors synthesised by auto-combustion approach, for optical display and anticounterfeiting technologies. Various characterization tools such as X-ray diffractometer (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Fourier transform infra-red (FTIR) Spectroscope, and Raman spectroscope have been employed to understand the morphology and crystal structure of M<sub>0.05</sub>,Eu<sub>0.05</sub>:Y<sub>0.90</sub>VO<sub>4</sub> (M = Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>) nanophosphor, which reveals the formation of a pure tetragonal structure and well crystalline phase. Moreover, the UV–Vis spectra, suggests that the as-synthesised material substantiated to possess an energy band gap of ∼3.6 eV conjecturing it as a wide-band material, and the refractive index (n) of the prepared samples has been deduced as ∼ 2.1. Among all alkali ions, Li<sup>+</sup>-codoped sample exhibits the most intense PL spectra. The enhancement in PL intensity has been observed due to the energy transfer of VO<sub>4</sub><sup>3−</sup>→Eu<sup>3+</sup> and the codoping of lithium ions acts as a good charge compensator. For the optimized sample CIE coordinates has been found as (0.59, 0.39) and CCT value as 1712 K, which suggest it as a prospective candidate for the warm LEDs. The optimized sample has further been investigated for the visualization of Latent fingerprint on glass slide and as security ink. It displays efficient applicability as a well-defined ridge features up to level III. Henceforth, the as-synthesised Li<sub>0.05</sub>,Eu<sub>0.05</sub>:Y<sub>0.90</sub>VO<sub>4</sub> nanophosphor may potentially be applied for multipurpose applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 8802-8815"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510903","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 : 2025-03-01DOI: 10.1016/j.ceramint.2024.12.274
Xiaomei Zeng , Xiangyu Zhang , Chang Xu , Zhong Zeng , Yangyang Yu , Alexander Tolstoguzov , Xiangdong Ma , Huayong Hu , Jun Zhang , Bing Yang , Sheng Liu , Vasiliy O. Pelenovich
In this study, we deposited LiNbO3 film ultrasonic transducers using RF magnetron sputtering technique. The effects of bias voltage applied to the samples, heat treatment, and deposition geometry on the structure, morphology, element distribution, phase composition, and piezoelectric properties of transducers were studied. The bias voltage significantly improves the uniformity of element distribution and partially suppresses the formation of secondary phases (LiNb3O8, NbO, and Nb2O5). The optimal bias value was within the range of 4–25 V, and higher bias voltages resulted in degradation of the transducer structure and piezoelectric performance. Short term heat treatment in air at 700 °C for 5 h significantly improved ultrasonic response. The influence of transducer thickness and tilt angle of columnar structure on piezoelectric response was also discussed. The maximum longitudinal and shear wave amplitudes were observed at tilt angles of 0 and ∼15 deg, respectively.
{"title":"Effects of bias voltage on the structure and ultrasonic response of LiNbO3 film transducers deposited by magnetron sputtering","authors":"Xiaomei Zeng , Xiangyu Zhang , Chang Xu , Zhong Zeng , Yangyang Yu , Alexander Tolstoguzov , Xiangdong Ma , Huayong Hu , Jun Zhang , Bing Yang , Sheng Liu , Vasiliy O. Pelenovich","doi":"10.1016/j.ceramint.2024.12.274","DOIUrl":"10.1016/j.ceramint.2024.12.274","url":null,"abstract":"<div><div>In this study, we deposited LiNbO<sub>3</sub> film ultrasonic transducers using RF magnetron sputtering technique. The effects of bias voltage applied to the samples, heat treatment, and deposition geometry on the structure, morphology, element distribution, phase composition, and piezoelectric properties of transducers were studied. The bias voltage significantly improves the uniformity of element distribution and partially suppresses the formation of secondary phases (LiNb<sub>3</sub>O<sub>8</sub>, NbO, and Nb<sub>2</sub>O<sub>5</sub>). The optimal bias value was within the range of 4–25 V, and higher bias voltages resulted in degradation of the transducer structure and piezoelectric performance. Short term heat treatment in air at 700 °C for 5 h significantly improved ultrasonic response. The influence of transducer thickness and tilt angle of columnar structure on piezoelectric response was also discussed. The maximum longitudinal and shear wave amplitudes were observed at tilt angles of 0 and ∼15 deg, respectively.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 8439-8445"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511860","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}
Vat photopolymerization of ceramic suspensions has received considerable attention due to its high precision and exceptional resolution, enabling the fabrication of intricate ceramic components. However, the polymer-based network formed during the printing process must be heated gradually to ensure the efficient release of gases generated from the decomposition of organic compounds, thereby preventing the formation of cracks in the ceramic structure. An alternative strategy to achieve ceramics with optimal properties is the incorporation of sintering additives into the compositions, which reduces the sintering temperature while enhancing densification of the parts during thermal treatments. This study examines the influence of debinding atmosphere (air or N₂) and sintering additives (TiO₂ and Nb₂O₅) on the fabrication of alumina ceramics using digital light processing, employing a commercially available, cost-effective, bottom-up LCD printer. Optimized debinding in an inert (N2) atmosphere produced crack-free components with improved densification after sintering at 1400 °C and 1600 °C. Both additives were effective in altering the sintering behavior of alumina, increasing diffusion rates and promoting the formation of intergranular phases. As a result, specimens with a relative density of approximately 97.5 % were achieved.
{"title":"Impact of debinding atmosphere and sintering additives on the fabrication of alumina ceramics via vat photopolymerization","authors":"P.L.A. Alves , I.L. Camargo , J.R. Verza , A.P. Luz","doi":"10.1016/j.ceramint.2024.12.336","DOIUrl":"10.1016/j.ceramint.2024.12.336","url":null,"abstract":"<div><div>Vat photopolymerization of ceramic suspensions has received considerable attention due to its high precision and exceptional resolution, enabling the fabrication of intricate ceramic components. However, the polymer-based network formed during the printing process must be heated gradually to ensure the efficient release of gases generated from the decomposition of organic compounds, thereby preventing the formation of cracks in the ceramic structure. An alternative strategy to achieve ceramics with optimal properties is the incorporation of sintering additives into the compositions, which reduces the sintering temperature while enhancing densification of the parts during thermal treatments. This study examines the influence of debinding atmosphere (air or N₂) and sintering additives (TiO₂ and Nb₂O₅) on the fabrication of alumina ceramics using digital light processing, employing a commercially available, cost-effective, bottom-up LCD printer. Optimized debinding in an inert (N<sub>2</sub>) atmosphere produced crack-free components with improved densification after sintering at 1400 °C and 1600 °C. Both additives were effective in altering the sintering behavior of alumina, increasing diffusion rates and promoting the formation of intergranular phases. As a result, specimens with a relative density of approximately 97.5 % were achieved.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 9063-9072"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512113","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 : 2025-03-01DOI: 10.1016/j.ceramint.2024.12.319
Siyu Gong , Ting Zhang , Bingguo Liu , Peng Liu , Yifan Niu , Zhenxing Yang , Yuhao Jin , Wang Chen , Guangxiong Ji , Shenghui Guo , Libo Zhang
The study introduces a microwave-assisted rutile seed crystal (RS) method to synthesise mixed-phase TiO2 nanoparticles, controlling the rutile TiO2 (TiO2-R) phase content () from 33.0 % to 99.3 % by adjusting the doping level of RS to 20.0 wt% in the metatitanic acid (MA). The sample, designated as MA-20, with the highest oxygen vacancy (Ov) concentration of 38.56 %, demonstrated over 99 % microwave absorption (minimum reflection loss () −56.8 dB) and a heating rate of 0.836 °C/s under 2000 W and 20 g. RS enhanced the dielectric property of MA, facilitating phase transition from anatase TiO2 (TiO2-A) to TiO2-R above 600 °C, with critical temperatures between 800 and 1000 °C. MA-20, with a surface area of 1.9226 m2/g and pore size distribution of 9.0851 nm, showed that higher RS doping levels promoted phase transition and grain growth, thereby enhancing the crystallinity and charge transfer efficiency. More than 50 % of MA-20 particles were under 10 nm, and 94 % were below 100 nm, confirming the synthesis of TiO2 nanomaterials. MA-20 exhibited excellent electromagnetic wave storage and conversion properties. Adjusting microwave parameters and RS levels controls , offering an efficient approach for preparing mixed phase TiO2 catalysts, essential for semiconductor photocatalysis and overcoming TiO2-A limitations.
{"title":"Synthesizing mixed-phase TiO2 semiconductor catalysts via microwave-assisted rutile seed crystal: A new approach","authors":"Siyu Gong , Ting Zhang , Bingguo Liu , Peng Liu , Yifan Niu , Zhenxing Yang , Yuhao Jin , Wang Chen , Guangxiong Ji , Shenghui Guo , Libo Zhang","doi":"10.1016/j.ceramint.2024.12.319","DOIUrl":"10.1016/j.ceramint.2024.12.319","url":null,"abstract":"<div><div>The study introduces a microwave-assisted rutile seed crystal (RS) method to synthesise mixed-phase TiO<sub>2</sub> nanoparticles, controlling the rutile TiO<sub>2</sub> (TiO<sub>2</sub>-R) phase content (<span><math><mrow><msub><mi>γ</mi><mi>R</mi></msub></mrow></math></span>) from 33.0 % to 99.3 % by adjusting the doping level of RS to 20.0 wt% in the metatitanic acid (MA). The sample, designated as MA-20, with the highest oxygen vacancy (O<sub>v</sub>) concentration of 38.56 %, demonstrated over 99 % microwave absorption (minimum reflection loss (<span><math><mrow><mi>R</mi><mi>L</mi></mrow></math></span>) −56.8 dB) and a heating rate of 0.836 °C/s under 2000 W and 20 g. RS enhanced the dielectric property of MA, facilitating phase transition from anatase TiO<sub>2</sub> (TiO<sub>2</sub>-A) to TiO<sub>2</sub>-R above 600 °C, with critical temperatures between 800 and 1000 °C. MA-20, with a surface area of 1.9226 m<sup>2</sup>/g and pore size distribution of 9.0851 nm, showed that higher RS doping levels promoted phase transition and grain growth, thereby enhancing the crystallinity and charge transfer efficiency. More than 50 % of MA-20 particles were under 10 nm, and 94 % were below 100 nm, confirming the synthesis of TiO<sub>2</sub> nanomaterials. MA-20 exhibited excellent electromagnetic wave storage and conversion properties. Adjusting microwave parameters and RS levels controls <span><math><mrow><msub><mi>γ</mi><mi>R</mi></msub></mrow></math></span>, offering an efficient approach for preparing mixed phase TiO<sub>2</sub> catalysts, essential for semiconductor photocatalysis and overcoming TiO<sub>2</sub>-A limitations.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 8880-8896"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512229","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}
High-temperature thin-film sensors on nickel-based alloy high-temperature components are important for design validation and health monitoring of such high-temperature components, however, maintaining good electrical insulation at high temperatures remains a challenge for the stability and reliability of thin-film sensors. In this study, an insulating coating on nickel-based alloy substrate is proposed to solve the electrical insulation problem of thin-film sensors. A layer of precursor ceramic slurry is prepared on a nickel-based alloy substrate by direct-write printing method, and then a layer of pure precursor liquid is spin-coated on it after vacuum pyrolysis, and then a four-layered structural insulating coating is formed by the vacuum pyrolysis at last. The coatings were characterized by SEM, EDS, FTIR, XRD and XPS for surface morphology, elemental content, functional groups, and physical phase composition. The electrical resistance of the coatings was tested at high temperatures and their adhesion at room temperature was tested. Finally, the temperature and thermal shock resistance of the coatings were verified by preparing thin-film thermistors and heat flux sensors on the coating. A high-temperature resistant electrically insulating coating is provided for the preparation of thin-film sensors on high-temperature nickel-based alloys.
{"title":"A ceramic coating from polymer-derived SiCNO for high-temperature electrical insulation on Ni-based alloy substrates","authors":"Zaifu Cui, Zhenguo Lu, Liwen Huang, Zitong Xu, Zhonghai Wang, Wenjin Duan, Huayu Che, Bohuai Gou, Qiyu Liang, Jiahong Huang, Xiaojun Chen","doi":"10.1016/j.ceramint.2024.12.347","DOIUrl":"10.1016/j.ceramint.2024.12.347","url":null,"abstract":"<div><div>High-temperature thin-film sensors on nickel-based alloy high-temperature components are important for design validation and health monitoring of such high-temperature components, however, maintaining good electrical insulation at high temperatures remains a challenge for the stability and reliability of thin-film sensors. In this study, an insulating coating on nickel-based alloy substrate is proposed to solve the electrical insulation problem of thin-film sensors. A layer of precursor ceramic slurry is prepared on a nickel-based alloy substrate by direct-write printing method, and then a layer of pure precursor liquid is spin-coated on it after vacuum pyrolysis, and then a four-layered structural insulating coating is formed by the vacuum pyrolysis at last. The coatings were characterized by SEM, EDS, FTIR, XRD and XPS for surface morphology, elemental content, functional groups, and physical phase composition. The electrical resistance of the coatings was tested at high temperatures and their adhesion at room temperature was tested. Finally, the temperature and thermal shock resistance of the coatings were verified by preparing thin-film thermistors and heat flux sensors on the coating. A high-temperature resistant electrically insulating coating is provided for the preparation of thin-film sensors on high-temperature nickel-based alloys.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 9142-9150"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510851","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 : 2025-03-01DOI: 10.1016/j.ceramint.2024.12.266
Yang Tong , Jinguang Lai , Yaxin Tian , Jiachen Liu , Wenle Pei , Hui Yong , Yuting Li , Jungang Li , Jifan Hu
Spin coating was used to fabricate 0–3 type BST/PVDF nanocomposite dielectric films using high-concentration suspensions. Polyvinylidene fluoride (PVDF) served as the matrix material, incorporating Ba0.8Sr0.2TiO3 (BST82) and Ba0.6Sr0.4TiO3 (BST64) nanoparticles, each with a particle size of 200 nm. This study investigates the microstructure, dielectric properties, dielectric temperature spectra, and energy storage performance of the BST/PVDF nanocomposite films with varying volume fractions of BST nanoparticles. The results reveal that as the volume fraction of BST82 and BST64 increases, the dielectric constant, maximum polarization, and remanent polarization increase, while the breakdown field strength decreases. The dielectric constant of the 0–3 type nanocomposite films incorporating BST fits best with the Jayasunder-Smith model across a range of 0 vol% to 20 vol%. Moreover, the maximum discharge energy storage densities of the BST82/PVDF and BST64/PVDF nanocomposite films, at a BST volume fraction of 7 vol%, are 5.74 J/cm³ and 4.21 J/cm³, respectively, under field strengths of 310 MV/m and 270 MV/m. Notably, analysis of the dielectric temperature spectrum reveals that high-temperature dielectric relaxation is primarily governed by the PVDF matrix, with the nanoparticle fillers having no significant impact on this phenomenon. In conclusion, both BST82 and BST64 nanoparticles influence the performance of the polymer films, with BST82-based nanocomposites showing higher breakdown field strength. This study provides valuable insights into the fabrication of high-performance 0–3 type nanoparticle/polymer dielectric nanocomposite films using concentrated BST/PVDF nanosuspensions and the spin coating method.
{"title":"Dielectric energy storage properties of 0–3 type BST/PVDF composite films","authors":"Yang Tong , Jinguang Lai , Yaxin Tian , Jiachen Liu , Wenle Pei , Hui Yong , Yuting Li , Jungang Li , Jifan Hu","doi":"10.1016/j.ceramint.2024.12.266","DOIUrl":"10.1016/j.ceramint.2024.12.266","url":null,"abstract":"<div><div>Spin coating was used to fabricate 0–3 type BST/PVDF nanocomposite dielectric films using high-concentration suspensions. Polyvinylidene fluoride (PVDF) served as the matrix material, incorporating Ba<sub>0.8</sub>Sr<sub>0.2</sub>TiO<sub>3</sub> (BST82) and Ba<sub>0.6</sub>Sr<sub>0.4</sub>TiO<sub>3</sub> (BST64) nanoparticles, each with a particle size of 200 nm. This study investigates the microstructure, dielectric properties, dielectric temperature spectra, and energy storage performance of the BST/PVDF nanocomposite films with varying volume fractions of BST nanoparticles. The results reveal that as the volume fraction of BST82 and BST64 increases, the dielectric constant, maximum polarization, and remanent polarization increase, while the breakdown field strength decreases. The dielectric constant of the 0–3 type nanocomposite films incorporating BST fits best with the Jayasunder-Smith model across a range of 0 vol% to 20 vol%. Moreover, the maximum discharge energy storage densities of the BST82/PVDF and BST64/PVDF nanocomposite films, at a BST volume fraction of 7 vol%, are 5.74 J/cm³ and 4.21 J/cm³, respectively, under field strengths of 310 MV/m and 270 MV/m. Notably, analysis of the dielectric temperature spectrum reveals that high-temperature dielectric relaxation is primarily governed by the PVDF matrix, with the nanoparticle fillers having no significant impact on this phenomenon. In conclusion, both BST82 and BST64 nanoparticles influence the performance of the polymer films, with BST82-based nanocomposites showing higher breakdown field strength. This study provides valuable insights into the fabrication of high-performance 0–3 type nanoparticle/polymer dielectric nanocomposite films using concentrated BST/PVDF nanosuspensions and the spin coating method.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 7","pages":"Pages 8362-8375"},"PeriodicalIF":5.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511748","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号