Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.10.147
Ruinan Zhang , Zhaoyang Liu , Lei Yuan , Tianpeng Wen , Jingkun Yu
This study investigates Y2O3-doped MgO ceramics prepared via a novel precursor process combined with sintering. Doping with 5 wt% Y2O3 forms a limited Y2O3-MgO solid solution, with yttrium silicate phases embedded within grains and at triple junctions. This significantly enhances densification, achieving a bulk density of 3.57 g cm−3, porosity of 5.56 %, and an average pore size reduction of 66.53 %. Compressive and bending strengths reach 69.37 MPa and 104.6 MPa, respectively. Analyses reveal that the ionic radius difference between Y3+ and Mg2+ induces lattice distortion, while synergistic grain boundary migration reduces dislocation density and increases lattice energy. These mechanisms collectively enhance densification and mechanical properties, providing a theoretical foundation for the low-cost preparation of stable MgO ceramics.
研究了采用新型前驱体与烧结相结合的方法制备y2o3掺杂MgO陶瓷。掺杂5 wt%的Y2O3形成了有限的Y2O3- mgo固溶体，在晶粒和三结处嵌入了硅酸钇相。这大大提高了致密性，实现了3.57 g cm−3的堆积密度，5.56%的孔隙率，平均孔径缩小66.53%。抗压和抗弯强度分别达到69.37 MPa和104.6 MPa。分析表明，Y3+和Mg2+离子半径的差异导致了晶格畸变，而协同晶界迁移降低了位错密度，提高了晶格能。这些机制共同增强了致密性和力学性能，为低成本制备稳定的MgO陶瓷提供了理论基础。
{"title":"Synergistic effects of lattice distortion and grain boundary migration on densification and mechanical properties in Y2O3-doped MgO-based ceramics","authors":"Ruinan Zhang , Zhaoyang Liu , Lei Yuan , Tianpeng Wen , Jingkun Yu","doi":"10.1016/j.ceramint.2025.10.147","DOIUrl":"10.1016/j.ceramint.2025.10.147","url":null,"abstract":"<div><div>This study investigates Y<sub>2</sub>O<sub>3</sub>-doped MgO ceramics prepared via a novel precursor process combined with sintering. Doping with 5 wt% Y<sub>2</sub>O<sub>3</sub> forms a limited Y<sub>2</sub>O<sub>3</sub>-MgO solid solution, with yttrium silicate phases embedded within grains and at triple junctions. This significantly enhances densification, achieving a bulk density of 3.57 g cm<sup>−3</sup>, porosity of 5.56 %, and an average pore size reduction of 66.53 %. Compressive and bending strengths reach 69.37 MPa and 104.6 MPa, respectively. Analyses reveal that the ionic radius difference between Y<sup>3+</sup> and Mg<sup>2+</sup> induces lattice distortion, while synergistic grain boundary migration reduces dislocation density and increases lattice energy. These mechanisms collectively enhance densification and mechanical properties, providing a theoretical foundation for the low-cost preparation of stable MgO ceramics.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 2","pages":"Pages 1392-1403"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145950391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.12.014
Wen-Zhong Lu , Burhan Ullah , Wen Lei , Tauqeer Ahmad
SrTiO3 is a quantum paraelectric with cubic symmetry that resists long-range ferroelectricity, but targeted substitution and defect ordering can unlock polar states. Here, we report novel ferroelectricity and high microwave permittivity in a novel Sr(1-1.5x)CexTiO3 (SCTO@x for x = 0.5) (SCTO) solid solution. XRD and Rietveld refinement reveal stabilization of an orthorhombic Pmmm phase, supported by TEM superlattice reflections linked to TiO6 tilts and antiparallel A-site displacements, while energy landscape analysis confirms this orthorhombic configuration as the strain-relieved ground state. Raman spectra show defect-activated Eg and A1g modes from oxygen-vacancy ordering, and XPS identifies a Ce3+/Ce4+ ↔ Ti3+/Ti4+ redox equilibrium with abundant vacancies. SEM/AFM reveal dense twin-striped grains that grow in size coarsen with sintering, reducing disorder. Dielectric spectra show a low-temperature relaxor response and a high-temperature transition: at 1270 °C both are diffuse and frequency-dependent, whereas at 1300 °C the high-temperature anomaly sharpens into a frequency-independent displacive ferroelectric transition (TC∼ 449 °C, TCW∼486 °C), supported by slim P–E loops, higher remanence, and TEM-confirmed domains. The coexistence of relaxor fluctuations with long-range ferroelectric order highlights a crossover from defect-induced short-range polarization to domain-driven coherence, which directly enhances microwave permittivity (εr∼82, Q × f∼12800 GHz, and τf ∼ 205 ppm/°C) by combining soft-mode contributions with reduced extrinsic losses. These findings establish that reduction-controlled defect ordering stabilizes orthorhombic ferroelectricity absent in pristine SrTiO3, providing a clear design pathway for functional dielectrics through defect-engineered lattice symmetry.
SrTiO3是一种具有立方对称的量子准电性物质，可以抵抗远距离铁电性，但靶向取代和缺陷排序可以解锁极性态。在这里，我们报道了一种新型Sr(1-1.5x)CexTiO3 (SCTO@x for x = 0.5) （SCTO）固溶体中的新型铁电性和高微波介电常数。XRD和Rietveld精化分析显示了正交相Pmmm的稳定性，TEM超晶格反射与TiO6倾斜和反平行a位位移有关，而能量景观分析证实了这种正交构型是应变缓解的基态。拉曼光谱显示缺陷激活的Eg和A1g模式，XPS发现Ce3+/Ce4+有丰富空位的Ce3+/ Ti4+氧化还原平衡。SEM/AFM分析表明，随着烧结的进行，晶粒尺寸逐渐变粗，无序性降低。介电光谱显示低温弛豫响应和高温转变：在1270°C时，两者都是漫射和频率相关的，而在1300°C时，高温异常加剧为频率无关的位移铁电转变（TC ~ 449°C, TCW ~ 486°C），由纤细的P-E环，高剩余物和tem确认的域支持。弛豫波动与长程铁电序的共存突出了从缺陷引起的短程极化到域驱动相干的交叉，这直接提高了微波介电常数（εr ~ 82， Q × f ~ 12800 GHz和τf ~ 205 ppm/°C），结合了软模式贡献和减少的外在损耗。这些发现表明，还原控制的缺陷有序稳定了原始SrTiO3中缺乏的正交铁电性，为通过缺陷工程晶格对称设计功能电介质提供了一条明确的途径。
{"title":"Novel ferroelectricity and high microwave dielectric permittivity in (Sr,Ce)TiO3 solid solution via reduction-controlled defect ordering","authors":"Wen-Zhong Lu , Burhan Ullah , Wen Lei , Tauqeer Ahmad","doi":"10.1016/j.ceramint.2025.12.014","DOIUrl":"10.1016/j.ceramint.2025.12.014","url":null,"abstract":"<div><div>SrTiO<sub>3</sub> is a quantum paraelectric with cubic symmetry that resists long-range ferroelectricity, but targeted substitution and defect ordering can unlock polar states. Here, we report novel ferroelectricity and high microwave permittivity in a novel Sr<sub>(1-1.5<em>x</em>)</sub>Ce<sub>x</sub>TiO<sub>3</sub> (SCTO@<sub>x</sub> for <em>x</em> = 0.5) (SCTO) solid solution. XRD and Rietveld refinement reveal stabilization of an orthorhombic <em>Pmmm</em> phase, supported by TEM superlattice reflections linked to TiO<sub>6</sub> tilts and antiparallel A-site displacements, while energy landscape analysis confirms this orthorhombic configuration as the strain-relieved ground state. Raman spectra show defect-activated E<sub>g</sub> and A<sub>1g</sub> modes from oxygen-vacancy ordering, and XPS identifies a Ce<sup>3+</sup>/Ce<sup>4+</sup> ↔ Ti<sup>3+</sup>/Ti<sup>4+</sup> redox equilibrium with abundant vacancies. SEM/AFM reveal dense twin-striped grains that grow in size coarsen with sintering, reducing disorder. Dielectric spectra show a low-temperature relaxor response and a high-temperature transition: at 1270 °C both are diffuse and frequency-dependent, whereas at 1300 °C the high-temperature anomaly sharpens into a frequency-independent displacive ferroelectric transition (T<sub>C</sub>∼ 449 °C, T<sub>CW</sub>∼486 °C), supported by slim P–E loops, higher remanence, and TEM-confirmed domains. The coexistence of relaxor fluctuations with long-range ferroelectric order highlights a crossover from defect-induced short-range polarization to domain-driven coherence, which directly enhances microwave permittivity (ε<sub>r</sub>∼82, Q × f∼12800 GHz, and τ<sub>f</sub> ∼ 205 ppm/°C) by combining soft-mode contributions with reduced extrinsic losses. These findings establish that reduction-controlled defect ordering stabilizes orthorhombic ferroelectricity absent in pristine SrTiO<sub>3</sub>, providing a clear design pathway for functional dielectrics through defect-engineered lattice symmetry.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 2","pages":"Pages 1948-1957"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145950149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.12.111
Rosiane M.C. Farias , Heryka R.A. Costa , Tainá L. Freire , Edvania T. Teófilo , Cleanio da Luz-Lima , Pedro de Lima-Neto , Adriana N. Correia , Romualdo R. Menezes , Thiago M.B.F. Oliveira
This study reports the development of Co-doped TiO2 nanofibers as efficient photoelectrocatalysts for the hydrogen evolution reaction (HER) under visible light incidence. Nanofibers were synthesized using air-heated solution blow spinning (A-HSBS) followed by calcination at 500 °C, and their structural, morphological, vibrational, and optical features were systematically investigated. The results confirmed the coexistence of Co2+ and Co3+ species, indicating successful dopant incorporation into the TiO2 lattice and suggesting suppression of oxygen vacancy formation, which correlates with the observed lattice contraction and the modified optical properties. Co-doped TiO2 displayed a heterophase composition of ∼60 % anatase and ∼40 % rutile, whereas the undoped TiO2 sample, prepared as a reference, contained only a minor fraction of rutile (∼3 %). These results suggest that cobalt doping markedly promotes rutile phase formation, enhancing its crystallization even at relatively low temperatures. Nanofibers were deposited on fluorine-doped tin oxide (FTO) substrates using Nafion® (NF) as a binding to engineer the working photocathode. Using a white light-emitting diode, the FTO/NF/TiO2-Co exhibited superior HER performance, with overpotentials ranging from 230 mV to 432 mV (10–100 mA cm−2), reflecting accelerated electron transfer and superior catalytic activity. The Faradaic efficiency reached ∼79 % at 1.67 mA h−1 cm−2, confirming the potential of FTO/NF/TiO2-Co for high-yield photoelectrochemical hydrogen production.
本研究报道了共掺杂TiO2纳米纤维作为可见光下析氢反应（HER）的高效光电催化剂的开发。采用空气加热溶液吹丝法（A-HSBS）在500℃下煅烧合成了纳米纤维，并对其结构、形态、振动和光学特性进行了系统的研究。结果证实Co2+和Co3+共存，表明掺杂剂成功掺入到TiO2晶格中，抑制了氧空位的形成，这与观察到的晶格收缩和光学性质的改变有关。共掺杂TiO2的异相组成为~ 60%锐钛矿和~ 40%金红石，而制备的未掺杂TiO2样品仅含有少量金红石（~ 3%）。这些结果表明，钴的掺杂显著促进金红石相的形成，即使在相对较低的温度下也能促进金红石相的结晶。纳米纤维沉积在氟掺杂氧化锡（FTO）衬底上，使用Nafion®（NF）作为结合物来设计工作光电阴极。使用白光二极管，FTO/NF/TiO2-Co表现出优异的HER性能，过电位范围为230 mV至432 mV (10-100 mA cm−2)，反映了加速的电子转移和优异的催化活性。在1.67 mA h−1 cm−2条件下，法拉第效率达到了79%，证实了FTO/NF/TiO2-Co在高收率光电化学制氢方面的潜力。
{"title":"Tailoring Co-doped anatase/rutile TiO2 nanofibers by air-heated solution blow spinning for photoelectrocatalytic hydrogen production","authors":"Rosiane M.C. Farias , Heryka R.A. Costa , Tainá L. Freire , Edvania T. Teófilo , Cleanio da Luz-Lima , Pedro de Lima-Neto , Adriana N. Correia , Romualdo R. Menezes , Thiago M.B.F. Oliveira","doi":"10.1016/j.ceramint.2025.12.111","DOIUrl":"10.1016/j.ceramint.2025.12.111","url":null,"abstract":"<div><div>This study reports the development of Co-doped TiO<sub>2</sub> nanofibers as efficient photoelectrocatalysts for the hydrogen evolution reaction (HER) under visible light incidence. Nanofibers were synthesized using air-heated solution blow spinning (A-HSBS) followed by calcination at 500 °C, and their structural, morphological, vibrational, and optical features were systematically investigated. The results confirmed the coexistence of Co<sup>2+</sup> and Co<sup>3+</sup> species, indicating successful dopant incorporation into the TiO<sub>2</sub> lattice and suggesting suppression of oxygen vacancy formation, which correlates with the observed lattice contraction and the modified optical properties. Co-doped TiO<sub>2</sub> displayed a heterophase composition of ∼60 % anatase and ∼40 % rutile, whereas the undoped TiO<sub>2</sub> sample, prepared as a reference, contained only a minor fraction of rutile (∼3 %). These results suggest that cobalt doping markedly promotes rutile phase formation, enhancing its crystallization even at relatively low temperatures. Nanofibers were deposited on fluorine-doped tin oxide (FTO) substrates using Nafion® (NF) as a binding to engineer the working photocathode. Using a white light-emitting diode, the FTO/NF/TiO<sub>2</sub>-Co exhibited superior HER performance, with overpotentials ranging from 230 mV to 432 mV (10–100 mA cm<sup>−2</sup>), reflecting accelerated electron transfer and superior catalytic activity. The Faradaic efficiency reached ∼79 % at 1.67 mA h<sup>−1</sup> cm<sup>−2</sup>, confirming the potential of FTO/NF/TiO<sub>2</sub>-Co for high-yield photoelectrochemical hydrogen production.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 3186-3197"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.12.166
John W. Makokha , Imre Szenti , Tamás Boldizsár , Zsolt Bán , Imre Sebők-Papp , László Nagy , Gábor Kozma , András Sápi , Ákos Kukovecz , Zoltán Kónya
Cordierite–mullite composites were synthesized via solid-state reactions using talc, kaolinite, alumina, and mullite precursors at 1360–1400 °C. XRD analysis confirmed α-cordierite (∼49.1 wt%) and mullite (∼38 wt%) as the main phases, along with ∼12.9 % amorphous content in the sintering window. At 1380–1400 °C, sintering induced a hexagonal-pseudohexagonal symmetry transition in cordierite and anisotropic mullite crystal growth. Composites with mullite milled at 200 rpm for 0.5–1 h developed a high aspect ratio (∼15.1), improving flexural strength by ∼37 %, while milling mullite at 200 rpm for 2–3 h reduced aspect ratio (<10), resulting in similar flexural strength compared to composites with initial mullite. This trend was attributed to varying crystal growth kinetics as a result of MPSD. The reduced thermal expansion (α∼3.17 × 10−6 K−1) along with moderate thermal conductivity (∼1.32 W m−1 K−1) reflects the influence of the cordierite-rich structure. Thermal shock evaluations revealed that the CBM200rpm0.5h formulation retained strength more effectively, a result linked to microstructural toughening associated with mullite morphology. The findings show that tailoring mullite aspect ratio via PSD is key to enhancing the high-temperature thermo-mechanical response of cordierite–mullite composites.
{"title":"Effect of mullite particle size distribution on crystal morphology and thermo-mechanical performance of Cordierite–Mullite composites","authors":"John W. Makokha , Imre Szenti , Tamás Boldizsár , Zsolt Bán , Imre Sebők-Papp , László Nagy , Gábor Kozma , András Sápi , Ákos Kukovecz , Zoltán Kónya","doi":"10.1016/j.ceramint.2025.12.166","DOIUrl":"10.1016/j.ceramint.2025.12.166","url":null,"abstract":"<div><div>Cordierite–mullite composites were synthesized via solid-state reactions using talc, kaolinite, alumina, and mullite precursors at 1360–1400 °C. XRD analysis confirmed α-cordierite (∼49.1 wt%) and mullite (∼38 wt%) as the main phases, along with ∼12.9 % amorphous content in the sintering window. At 1380–1400 °C, sintering induced a hexagonal-pseudohexagonal symmetry transition in cordierite and anisotropic mullite crystal growth. Composites with mullite milled at 200 rpm for 0.5–1 h developed a high aspect ratio (∼15.1), improving flexural strength by ∼37 %, while milling mullite at 200 rpm for 2–3 h reduced aspect ratio (<10), resulting in similar flexural strength compared to composites with initial mullite. This trend was attributed to varying crystal growth kinetics as a result of MPSD. The reduced thermal expansion (α∼3.17 × 10<sup>−6</sup> K<sup>−1</sup>) along with moderate thermal conductivity (∼1.32 W m<sup>−1</sup> K<sup>−1</sup>) reflects the influence of the cordierite-rich structure. Thermal shock evaluations revealed that the CBM200rpm0.5h formulation retained strength more effectively, a result linked to microstructural toughening associated with mullite morphology. The findings show that tailoring mullite aspect ratio via PSD is key to enhancing the high-temperature thermo-mechanical response of cordierite–mullite composites.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 3734-3743"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.12.175
Zhengwei Li , Shu Chen , Zhiwu Xu , Xueye Du , He Zhang , Jiuchun Yan
Pure filler metals provide predictable performance such as better thermal conductivity, electrical conductivity and corrosion resistance. But pure metals always exhibit relatively weak wetting capability to the substrate, especially ceramic materials. In this work, the wetting possibility of pure Sn to AlN ceramic with ultrasonic assistance was studied. Results show that the wetting of pure Sn to AlN is realized with the help of ultrasonic at a low temperature of 250 °C. The bonding presents two forms at the Sn/AlN interface. The first shows direct contact of Sn and AlN atoms without transition layer. The other features an amorphous transition layer with uneven thicknesses. Both forms show the concentration of Sn and O at the wetting interface. The wetting mechanism was also discussed: when the mole fraction of Sn approaches 50 %, the formation enthalpy ΔHSn-O reaches its minimum. The bonding layer shows high amorphous formation potential. However, the bonding layer shows crystalline structure in most regions with the content fluctuation of Sn and O. Defect-free joint with shear strength of 29.4 MPa is obtained at ultrasonic power of 1000 W. Such strength equals to those ultrasonically soldered joints using active Sn-based solder.
{"title":"Ultrasonic activation wetting and bonding of pure Sn metal to AlN ceramic at low temperature","authors":"Zhengwei Li , Shu Chen , Zhiwu Xu , Xueye Du , He Zhang , Jiuchun Yan","doi":"10.1016/j.ceramint.2025.12.175","DOIUrl":"10.1016/j.ceramint.2025.12.175","url":null,"abstract":"<div><div>Pure filler metals provide predictable performance such as better thermal conductivity, electrical conductivity and corrosion resistance. But pure metals always exhibit relatively weak wetting capability to the substrate, especially ceramic materials. In this work, the wetting possibility of pure Sn to AlN ceramic with ultrasonic assistance was studied. Results show that the wetting of pure Sn to AlN is realized with the help of ultrasonic at a low temperature of 250 °C. The bonding presents two forms at the Sn/AlN interface. The first shows direct contact of Sn and AlN atoms without transition layer. The other features an amorphous transition layer with uneven thicknesses. Both forms show the concentration of Sn and O at the wetting interface. The wetting mechanism was also discussed: when the mole fraction of Sn approaches 50 %, the formation enthalpy ΔH<sub>Sn-O</sub> reaches its minimum. The bonding layer shows high amorphous formation potential. However, the bonding layer shows crystalline structure in most regions with the content fluctuation of Sn and O. Defect-free joint with shear strength of 29.4 MPa is obtained at ultrasonic power of 1000 W. Such strength equals to those ultrasonically soldered joints using active Sn-based solder.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 3826-3836"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.12.172
Jing-Tong Lu , Ze Xu , Weiru Wen , Wanting Cao , Yanqi Wu , Fanda Zeng , Chaofeng Wu , Fangzhou Yao , Weiwei Gao , Yan Wei , Ke Wang , Ke Bi
Vibrating mesh nebulizers (VMNs) have been extensively used as household medical devices. However, lead-free VMNs have rarely been reported since their invention. Herein, we present a (K,Na)NbO3-based (KNN) lead-free piezoceramic with comparable electrical properties to those of conventional lead-containing counterparts, and for the first time, develop an environmentally benign VMN. The KNN-based piezoceramic demonstrates better electric-field-induced strain (ΔS = 0.23 %) and normalized strain (d33∗ = 437 p.m./V) compared to lead zirconate titanate (PZT), which is commercially employed in VMNs. Both theoretical finite element analysis (FEA) and experimental 3D laser Doppler vibrometry confirm that the KNN-based piezoceramic component exhibits larger center displacement than PZT. Furthermore, the KNN-based nebulizer generates finer aerosol droplets 3.33 ± 0.04 μm when using water as a substitute for medical fluids. This breakthrough not only highlights the potential of KNN-based materials as a sustainable alternative to lead-based piezoelectric but also paves the way for the development of eco-friendly medical devices.
{"title":"Lead-free (K, Na)NbO3-based piezoceramics for sustainable application in vibrating mesh nebulizers","authors":"Jing-Tong Lu , Ze Xu , Weiru Wen , Wanting Cao , Yanqi Wu , Fanda Zeng , Chaofeng Wu , Fangzhou Yao , Weiwei Gao , Yan Wei , Ke Wang , Ke Bi","doi":"10.1016/j.ceramint.2025.12.172","DOIUrl":"10.1016/j.ceramint.2025.12.172","url":null,"abstract":"<div><div>Vibrating mesh nebulizers (VMNs) have been extensively used as household medical devices. However, lead-free VMNs have rarely been reported since their invention. Herein, we present a (K,Na)NbO<sub>3</sub>-based (KNN) lead-free piezoceramic with comparable electrical properties to those of conventional lead-containing counterparts, and for the first time, develop an environmentally benign VMN. The KNN-based piezoceramic demonstrates better electric-field-induced strain (Δ<em>S</em> = 0.23 %) and normalized strain (<em>d</em><sub>33</sub>∗ = 437 p.m./V) compared to lead zirconate titanate (PZT), which is commercially employed in VMNs. Both theoretical finite element analysis (FEA) and experimental 3D laser Doppler vibrometry confirm that the KNN-based piezoceramic component exhibits larger center displacement than PZT. Furthermore, the KNN-based nebulizer generates finer aerosol droplets 3.33 ± 0.04 μm when using water as a substitute for medical fluids. This breakthrough not only highlights the potential of KNN-based materials as a sustainable alternative to lead-based piezoelectric but also paves the way for the development of eco-friendly medical devices.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 3807-3815"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.11.404
Kubilay Ozdemir , Hakan Ates , Mete Bakir
This study was conducted to survey a comprehensive comparison of different mixing techniques on BaTiO3-graphene nanoplatelet (GNP) composites, focusing on powder homogeneity, microstructural, chemical, thermal, morphological, electrical and mechanical properties. For this purpose, we have employed scanning electron microscopy (SEM) to analyse the manual sample mixing, which led to poor dispersion and prominent graphene clusters, confirming the significant limitations of this technique in achieving uniform distribution. It was found that dispersion relative to the manual specimen mixing was improved in the presence of magnetic stirring; however, it still exhibited localized GNP agglomerations and heterogeneity. In contrast, ball milling provided the most uniform graphene distribution within the BaTiO3 matrix while effectively preserving the crystal structure of BaTiO3, as illustrated by X-ray diffraction (XRD) and Fourier-transform Infrared (FTIR) spectroscopy analyses, respectively. Additionally, differential thermal analysis (DTA) measurements indicated stable thermal behaviour in the samples, with only minor phase changes observed during heating and cooling cycles. In addition, mechanical testing evaluations further demonstrated that ball milling resulted in significantly higher values of hardness, flexural strength and reliability than the other procedures. At the same time, electrical calculations proved the formation of well-connected graphene networks which enhanced conductivity. The main objective of the study is to highlight how the mixing method can strongly affect the process-structure-property relationships in ceramic matrix composites. We believe that our newly developed techniques provide valuable information, insights, and knowledge for optimizing the BaTiO3-GNP composite fabrication in advanced technological applications.
{"title":"Effect of mixing methods on the fabrication and microstructural properties of BaTiO3-Based ceramic nanocomposites reinforced with graphene nanoplatelets","authors":"Kubilay Ozdemir , Hakan Ates , Mete Bakir","doi":"10.1016/j.ceramint.2025.11.404","DOIUrl":"10.1016/j.ceramint.2025.11.404","url":null,"abstract":"<div><div>This study was conducted to survey a comprehensive comparison of different mixing techniques on BaTiO<sub>3</sub>-graphene nanoplatelet (GNP) composites, focusing on powder homogeneity, microstructural, chemical, thermal, morphological, electrical and mechanical properties. For this purpose, we have employed scanning electron microscopy (SEM) to analyse the manual sample mixing, which led to poor dispersion and prominent graphene clusters, confirming the significant limitations of this technique in achieving uniform distribution. It was found that dispersion relative to the manual specimen mixing was improved in the presence of magnetic stirring; however, it still exhibited localized GNP agglomerations and heterogeneity. In contrast, ball milling provided the most uniform graphene distribution within the BaTiO<sub>3</sub> matrix while effectively preserving the crystal structure of BaTiO<sub>3</sub>, as illustrated by X-ray diffraction (XRD) and Fourier-transform Infrared (FTIR) spectroscopy analyses, respectively. Additionally, differential thermal analysis (DTA) measurements indicated stable thermal behaviour in the samples, with only minor phase changes observed during heating and cooling cycles. In addition, mechanical testing evaluations further demonstrated that ball milling resulted in significantly higher values of hardness, flexural strength and reliability than the other procedures. At the same time, electrical calculations proved the formation of well-connected graphene networks which enhanced conductivity. The main objective of the study is to highlight how the mixing method can strongly affect the process-structure-property relationships in ceramic matrix composites. We believe that our newly developed techniques provide valuable information, insights, and knowledge for optimizing the BaTiO<sub>3</sub>-GNP composite fabrication in advanced technological applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 2840-2857"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996235","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}
MXenes are two-dimensional transition metal carbides/nitrides known for their high electrical conductivity. However, this electrical property can deteriorate when surface-terminated groups such as chloride, fluorine, and hydroxide are attached, as these groups do not facilitate efficient electron transport. High electrical conductivity in MXenes is essential for achieving fast charging/discharging rates, as well as higher energy density, making them suitable as anode materials in energy storage applications. The versatility and tunability of MXene chemistry make them promising candidates for designing power-sourcing devices. This work focuses on enhancing the conductivity of Ti3C2Tx MXene through surface decoration with Ag, Ce, and La via chemical reduction, followed by sintering under a nitrogen atmosphere at 400 °C. The shifting of the (002) and (004) 2θ peaks, along with the formation of (006) planes in CeMXTx and LaMXTx, confirms an increase in the interlayer spacing of the decorated MXenes. This is further supported by Raman spectroscopy, which shows the emergence of prominent D-band and G-band peaks at 1390 cm−1, and 1585-1602 cm−1, respectively. Surface decoration also alters the electronic structure of MXene, as evidenced by the reduction in bandgap energy-for example, from 1.23 eV in MXTx to 0.95 eV in LaMXTx. HRTEM analysis confirms an increase in interlayer spacing from 0.28 nm (MXTx) to 0.41 nm (LaMXTx). Among the samples studied, lanthanum-decorated MXene exhibited the highest electrical conductivity, reaching 4198 ± 167 S cm−1.
{"title":"Modulation of the electronic properties of 2D-MXene (Ti3C2Tx) via surface-covalent functionalization with La/Ce/Ag","authors":"Sukanta Badaik , Suryakanta Nayak , Balram Ambade , Tapan Kumar Rout","doi":"10.1016/j.ceramint.2025.12.076","DOIUrl":"10.1016/j.ceramint.2025.12.076","url":null,"abstract":"<div><div>MXenes are two-dimensional transition metal carbides/nitrides known for their high electrical conductivity. However, this electrical property can deteriorate when surface-terminated groups such as chloride, fluorine, and hydroxide are attached, as these groups do not facilitate efficient electron transport. High electrical conductivity in MXenes is essential for achieving fast charging/discharging rates, as well as higher energy density, making them suitable as anode materials in energy storage applications. The versatility and tunability of MXene chemistry make them promising candidates for designing power-sourcing devices. This work focuses on enhancing the conductivity of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> MXene through surface decoration with Ag, Ce, and La <em>via</em> chemical reduction, followed by sintering under a nitrogen atmosphere at 400 <sup>°</sup>C. The shifting of the (002) and (004) 2θ peaks, along with the formation of (006) planes in CeMXTx and LaMXTx, confirms an increase in the interlayer spacing of the decorated MXenes. This is further supported by Raman spectroscopy, which shows the emergence of prominent D-band and G-band peaks at 1390 cm<sup>−1</sup>, and 1585-1602 cm<sup>−1</sup>, respectively. Surface decoration also alters the electronic structure of MXene, as evidenced by the reduction in bandgap energy-for example, from 1.23 eV in MXTx to 0.95 eV in LaMXTx. HRTEM analysis confirms an increase in interlayer spacing from 0.28 nm (MXTx) to 0.41 nm (LaMXTx). Among the samples studied, lanthanum-decorated MXene exhibited the highest electrical conductivity, reaching 4198 ± 167 S cm<sup>−1</sup>.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 2901-2912"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01DOI: 10.1016/j.ceramint.2025.12.112
Zhi-Lin Ji, Weijia Wang, Yuxin Jia, Lin Lei, Chun-Hai Wang, Ning Yang, Huiqing Fan
LnTaO4 and LnNbO4 compounds exhibit comparable crystal structures and chemical characteristics. However, their microwave dielectric behaviors differ markedly, which highlights the need to clarify the origin of these discrepancies. In this work, SmTaO4 was selected as a model system to investigate the effects of Bi3+ doping on its crystal structure and microwave dielectric properties. Sm1-xBixTaO4 (0 ≤ x ≤ 0.04) solid solutions were prepared by solid-state reaction and sintered to more than 98.5 % relative density at 1600 °C for x = 0 and 1550 °C for 0 < x ≤ 0.04. XRD, Rietveld refinement, and EDS mapping confirmed the successful incorporation of Bi3+. The microwave dielectric properties of samples exhibit high Q × f, which decreases from 2.03 × 105 to 9.12 × 104 GHz as x increases from 0 to 0.04. The reduction in Q × f with increasing Bi content is attributed to enhanced lattice anharmonicity, grain boundary loss, and conduction loss. The τf of Sm1-xBixTaO4 shifts slightly from −76.32 to −70.48 ppm °C−1 as x increases from 0 to 0.04. The fundamental difference in the effect of Bi3+ doping on τf between LnTaO4 and LnNbO4 originates from the higher lattice rigidity of the LnTaO4 crystal structure, which limits the solubility of Bi3+ and results in only minor modifications impact on the crystal structure and phonon behavior.
{"title":"Effect of Bi substitution on the structural, optical, electrical, and microwave dielectric properties of Sm1-xBixTaO4 ceramics","authors":"Zhi-Lin Ji, Weijia Wang, Yuxin Jia, Lin Lei, Chun-Hai Wang, Ning Yang, Huiqing Fan","doi":"10.1016/j.ceramint.2025.12.112","DOIUrl":"10.1016/j.ceramint.2025.12.112","url":null,"abstract":"<div><div>LnTaO<sub>4</sub> and LnNbO<sub>4</sub> compounds exhibit comparable crystal structures and chemical characteristics. However, their microwave dielectric behaviors differ markedly, which highlights the need to clarify the origin of these discrepancies. In this work, SmTaO<sub>4</sub> was selected as a model system to investigate the effects of Bi<sup>3+</sup> doping on its crystal structure and microwave dielectric properties. Sm<sub>1-<em>x</em></sub>Bi<sub><em>x</em></sub>TaO<sub>4</sub> (0 ≤ <em>x</em> ≤ 0.04) solid solutions were prepared by solid-state reaction and sintered to more than 98.5 % relative density at 1600 °C for <em>x</em> = 0 and 1550 °C for 0 < <em>x</em> ≤ 0.04. XRD, Rietveld refinement, and EDS mapping confirmed the successful incorporation of Bi<sup>3+</sup>. The microwave dielectric properties of samples exhibit high Q × <em>f</em>, which decreases from 2.03 × 10<sup>5</sup> to 9.12 × 10<sup>4</sup> GHz as <em>x</em> increases from 0 to 0.04. The reduction in Q × <em>f</em> with increasing Bi content is attributed to enhanced lattice anharmonicity, grain boundary loss, and conduction loss. The <em>τ</em><sub><em>f</em></sub> of Sm<sub>1-<em>x</em></sub>Bi<sub><em>x</em></sub>TaO<sub>4</sub> shifts slightly from −76.32 to −70.48 ppm °C<sup>−1</sup> as <em>x</em> increases from 0 to 0.04. The fundamental difference in the effect of Bi<sup>3+</sup> doping on <em>τ</em><sub><em>f</em></sub> between LnTaO<sub>4</sub> and LnNbO<sub>4</sub> originates from the higher lattice rigidity of the LnTaO<sub>4</sub> crystal structure, which limits the solubility of Bi<sup>3+</sup> and results in only minor modifications impact on the crystal structure and phonon behavior.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 3198-3207"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996420","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}
Compressive strength is vital for porous cordierite ceramics widely used in thermal storage, thermal insulation, refractory materials, and catalyst supports, but conventional reinforcement methods often come at the cost of sacrificing porosity. This work aimed to produce high-strength porous cordierite ceramics from emulsions stabilized by submicron-sized, plate-like cordierite particles. The strong adsorption of pentylamine-modified particles at the oil-water interface and the formation of an attractive particle network throughout the continuous phase stabilized the emulsions to withstand room-temperature drying without structural distortion. The high-aspect-ratio particle morphology facilitated their preferred orientation during emulsification and sintering processes, thereby imparting remarkable mechanical properties to the ceramic bodies. By adjusting sintering temperature and pentylamine concentration, compressive strengths ranging from 32.6 to 67.4 MPa were obtained from porous cordierites with a porosity of 54.8 %–69.0 %. Such high strength values were attributed to the strong pore walls endowed by high interfacial coverage and the dense struts formed by stacked plate-like particles in the continuous phase.
{"title":"High-strength porous cordierite ceramics from emulsions stabilized by plate-like cordierite particles","authors":"Zijing Hao , Jiaqing Zhao , Jinhong Li , Jianbo Gao","doi":"10.1016/j.ceramint.2025.12.135","DOIUrl":"10.1016/j.ceramint.2025.12.135","url":null,"abstract":"<div><div>Compressive strength is vital for porous cordierite ceramics widely used in thermal storage, thermal insulation, refractory materials, and catalyst supports, but conventional reinforcement methods often come at the cost of sacrificing porosity. This work aimed to produce high-strength porous cordierite ceramics from emulsions stabilized by submicron-sized, plate-like cordierite particles. The strong adsorption of pentylamine-modified particles at the oil-water interface and the formation of an attractive particle network throughout the continuous phase stabilized the emulsions to withstand room-temperature drying without structural distortion. The high-aspect-ratio particle morphology facilitated their preferred orientation during emulsification and sintering processes, thereby imparting remarkable mechanical properties to the ceramic bodies. By adjusting sintering temperature and pentylamine concentration, compressive strengths ranging from 32.6 to 67.4 MPa were obtained from porous cordierites with a porosity of 54.8 %–69.0 %. Such high strength values were attributed to the strong pore walls endowed by high interfacial coverage and the dense struts formed by stacked plate-like particles in the continuous phase.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 3","pages":"Pages 3439-3446"},"PeriodicalIF":5.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996507","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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