Ceramics International最新文献

{"title":"Design and thermophysical properties of disordered fluorite-structured high-entropy zirconate","authors":"Tianxiong ZhuYi ,&nbsp;Wei Zheng ,&nbsp;Yue Sun ,&nbsp;Yiling Huang ,&nbsp;Yi Zeng","doi":"10.1016/j.ceramint.2025.06.219","DOIUrl":"10.1016/j.ceramint.2025.06.219","url":null,"abstract":"<div><div><span>To address the challenges of poor phase stability and insufficient sintering resistance in conventional yttria-stabilized zirconia (YSZ) thermal barrier coatings<span> at high temperatures (&gt;1473 K), this study proposes the development of novel rare-earth zirconates through a high-entropy strategy and structural design. A-site high-entropy zirconates (6RE)</span></span>₂(Zr_1-xCex)₂O₇<span> with equimolar doping of six rare-earth elements (La, Lu, Yb, Tm, Er, Ho) were synthesized via solid-state reaction, yielding four disordered fluorite-structured samples (HZO, HZCO1, HZCO2, HZCO3) with varying Ce contents. Systematic characterization of their structural, thermophysical, and mechanical properties revealed that all samples formed single-phase disordered fluorite structures (space group Fm3m). Lattice distortion enhanced phonon scattering, while B-site Ce doping further reduced thermal conductivity to 1.29–1.63 W/m·K (400–1000 °C), representing 48 % reduction compared to YSZ (2.5–2.6 W/m∙K). The thermal expansion coefficients (10.0 × 10</span>⁻⁶-12 × 10⁻⁶ K⁻¹<span>, 800–1000 °C) demonstrated excellent compatibility with Ni/CoCrAlY bond coats. Notably, the materials exhibited superior damage tolerance, with a low brittleness index of 3.70 μm</span>^−1/2<span>. Analysis of mass and size disorder parameters elucidated structure-property correlations between disorder degree, thermal conductivity, and mechanical performance. This work provides experimental evidence and design principles for high-entropy zirconates in advanced thermal barrier coatings, highlighting their integrated advantages of ultralow thermal conductivity, high thermal expansion, and robust mechanical properties.</span></div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39843-39854"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922579","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}

{"title":"A novel preparation process of tungsten carbide in molten salt: Carbon internal recycling","authors":"Yaoyao Wang ,&nbsp;Liwen Zhang ,&nbsp;Xiaoli Xi ,&nbsp;Zuoren Nie","doi":"10.1016/j.ceramint.2025.06.255","DOIUrl":"10.1016/j.ceramint.2025.06.255","url":null,"abstract":"<div><div><span>This study proposes a novel process for the clean production of tungsten carbide from the perspective of internal recycling of carbon. On the basis of NaCl-KCl-Na</span>₂WO₄-Na₂O molten salts capturing and converting CO₂<span>, the loss of graphite anode is fixed in the molten salt system. The clean production of nano-tungsten carbide<span> and the internal recycling of carbon were realized. Firstly, the carbon transfer pathway from graphite anode to molten salt to electrolysis products was demonstrated by the characterization of each part of the electrolysis system. Subsequently, the effects of electrolysis voltage, temperature and Na</span></span>₂O addition on carbon internal recycling were evaluated. It was found that the increase of Na₂O addition could effectively reduce the anode CO₂ gas spillage. When 0.9 wt% Na₂<span>O was added, the amount of unfixed carbon could be reduced to 1.63 %. And the WC products with higher purity were obtained at a voltage of 3 V and a temperature of 800°C. Additionally, the average diffusion coefficient of CO</span>₃²⁻ (6.91 × 10⁻⁹ cm²s⁻¹) was much larger than that of WO₄²⁻<span><span>. It suggests that the first stage of electrolysis has a rapid carbon transfer rate, which provides a prerequisite for the nucleation of WC. The process provides a clean production route for the production of tungsten carbide </span>nanoparticles in a low-carbon and environmentally friendly way.</span></div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 40223-40233"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922680","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}

{"title":"Synthesis and spectroscopic analysis in KYF4: Ce3+/Gd3+: A UV emitting phosphor synthesized by solid state metathesis","authors":"Nilesh S. Ugemuge ,&nbsp;Shruti P. Dhale ,&nbsp;Vartika S. Singh ,&nbsp;S.V. Moharil","doi":"10.1016/j.ceramint.2025.06.256","DOIUrl":"10.1016/j.ceramint.2025.06.256","url":null,"abstract":"<div><div>Synthesis of KYF₄<span><span> by solid state metathesis is reported. XRD results indicated almost </span>pure cubic phase with some weak lines of hexagonal phases. Luminescence of Ce</span>³⁺, on the other hand, showed presence of Ce³⁺<span> centres in both cubic and hexagonal phases. Luminescence spectra<span> in two phases differ. Emission in the cubic phase lies at longer wavelengths as compared to that in the hexagonal phase. The difference is attributed to the weaker crystal field in the hexagonal phase. Two phase structure was not reflected in the luminescence of Gd</span></span>³⁺. Gd³⁺ luminescence originates in f-f transitions which are less sensitive to the structural changes as compared to the f-d transitions of Ce³⁺. These results can explain the inconsistencies in the literature reports on Ce³⁺ luminescence in KYF₄. These investigations also furnish a fast method for preparing KYF₄ based phosphors.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 40234-40243"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922681","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}

{"title":"Dielectric properties of Sm2GeO5 ceramics at microwave frequencies and their influencing factors","authors":"Yuan Nie,&nbsp;Yanjun Liu,&nbsp;Ziqi Zhao,&nbsp;Wenjie Zhang,&nbsp;Weilin Chen,&nbsp;Mengyao Wang,&nbsp;Fangyi Huang,&nbsp;Xiuli Chen,&nbsp;Huanfu Zhou","doi":"10.1016/j.ceramint.2025.06.227","DOIUrl":"10.1016/j.ceramint.2025.06.227","url":null,"abstract":"<div><div>In this study, low-permittivity Sm₂GeO₅<span><span> ceramics were synthesized via solid-state reaction. XRD and </span>Rietveld refinement confirmed a monoclinic crystal structure (space group </span><em>P</em>2₁/<em>c</em><span>). SEM was employed to analyze grain growth. The microwave dielectric properties<span> were systematically investigated, revealing that the void ratio critically influences the dielectric constant of the samples. The </span></span><em>Q×f</em> values of the ceramics exhibited a strong dependence on the void fraction, packing fraction, and lattice energy. Meanwhile, the valence state of B-site cations played a critical role in determining the temperature stability. When sintered at 1400 °C, the ceramics achieved a high relative density of 95.74 %, further supporting their optimized microwave dielectric performance. Excellent microwave dielectric properties were achieved: <em>ε</em>_<em>r</em> = 13.72, <em>Q×f</em> = 43723 GHz, <em>τ</em>_<em>f</em> = −84.21 ppm/°C. This study provides a comprehensive analysis of the key factors influencing the microwave dielectric properties of Sm₂GeO₅ ceramics. The excellent microwave dielectric properties of Sm₂GeO₅ ceramics indicate that they have promising applications in radar, mobile communication base stations, and satellite navigation.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39946-39952"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922856","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}

{"title":"Effect of shear rate on the rheological and crystallization behaviors of CaO-SiO2-CaF2-Ce2O3 slag melt at high temperature","authors":"Wentao Guo ,&nbsp;Xi Lan ,&nbsp;Yongli Jin ,&nbsp;Ziqi Ding ,&nbsp;Jintao Gao ,&nbsp;Zhancheng Guo ,&nbsp;Zengwu Zhao","doi":"10.1016/j.ceramint.2025.06.228","DOIUrl":"10.1016/j.ceramint.2025.06.228","url":null,"abstract":"<div><div><span>The irreplaceability role of rare earths in high-performance materials, such as ceramics, highlighting the significance of rare earth extraction<span><span>. Strengthening the crystallization growth of the rare earth phase in rare earth slag is crucial for ensuring effective subsequent rare earth enrichment and separation. However, viscosity plays a major role in the characteristics of high-temperature melts and the </span>crystallization process. In this study, an internal column rotation method was used to measure the viscosity of CaO-SiO</span></span>₂-CaF₂-Ce₂O₃<span> slag melts. The effect of shear rate on the rheological behavior of CaO-SiO</span>₂-CaF₂-Ce₂O₃ slag with varying Ce₂O₃ and CaF₂ contents, and CaO/SiO₂ ratio was investigated by examining the viscosity evolution during the rare earth crystallization growth process. The rheological behavior of the CaO-SiO₂-CaF₂-Ce₂O₃<span> slag was elucidated in regions of liquid phase, low solid phase, and high solid phase, providing insight into the viscosity changes of non-Newtonian flowing melts. Based on this, the effect of shear rate on the crystallization behavior of rare earth phases was investigated to provide a basis for improving the subsequent separation of rare earth phases.</span></div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39953-39961"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922857","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}

{"title":"Effect of V5+/V4+ substitution on structural and magnetic orderings of SrFeO3-δ","authors":"Rakhi Saha ,&nbsp;Koyal Suman Samantaray ,&nbsp;P. Maneesha ,&nbsp;Suresh Chandra Baral ,&nbsp;Sachindra Nath Sarangi ,&nbsp;Rajashri Urkude ,&nbsp;Biplab Ghosh ,&nbsp;R. Mittal ,&nbsp;Mayanak K. Gupta ,&nbsp;Abdelkarim Mekki ,&nbsp;Khalil Harrabi ,&nbsp;Somaditya Sen","doi":"10.1016/j.ceramint.2025.06.220","DOIUrl":"10.1016/j.ceramint.2025.06.220","url":null,"abstract":"<div><div>SrFeO_3-δ<span><span> is a structurally versatile material, showing cubic (C) symmetry at δ = 0, which transitions to tetragonal (T) and then orthorhombic (Or) with increasing oxygen vacancies. These structural changes alter magnetic behavior through variations in bond angles and lengths, enabling both </span>antiferromagnetic (AFM) and ferromagnetic (FM) interactions between Fe</span>⁴⁺/Fe³⁺<span> ions and oxygen (or vacancies). While such tunable magnetic phases offer rich physics and potential applications, achieving room-temperature (RT) FM remains challenging. This study explores V</span>⁵⁺/V⁴⁺ doping in SrFeO_3-δ (SrFe_1-xV_xO_3-δ<span><span>; 0 ≤ x ≤ 0.03) to induce FM persisting up to RT and investigates its structural-magnetic correlation. Structural analysis from X-ray diffraction (XRD) and Raman spectroscopy, supported by </span>phonon mode calculations, reveals that SrFeO</span>_3-δ<span><span><span> is in a mixed T-Or phase. At the same time, V-doped samples exhibit an emerging C-phase in a dominant T-lattice. Magnetic hysteresis (M − H) loops show notable FM behavior within the AFM matrix at low temperature ∼10K, with a FM and paramagnetic phase at </span>room temperature. Temperature-dependent magnetization measurements indicate a T-phase related </span>Néel temperature (</span><em>T</em>_<em>N</em><span>) shift from 70K to 55K in the doped samples as compared to the pure<span> one. An increased magnetization difference between the field-cooled (FC) and zero-field-cooled (ZFC) data with increasing V-content suggests an increasing magnetic frustration due to competing FM/AFM exchange interactions. X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) analyses reveal a rise in Fe</span></span>³⁺ and V⁵⁺<span> states, affecting oxygen vacancy distributions and corresponding structural shifts seen in XRD and Raman results. The multivalent Fe</span>³⁺/Fe⁴⁺ and V⁴⁺/V⁵⁺ states enhance Double-Exchange (DE) interactions (Fe³⁺-O-Fe⁴⁺ and Fe³⁺-O-V⁵⁺), and V_O-mediated Fe³⁺-V_O-Fe³⁺<span> interaction, promoting ferromagnetism. Moreover, frequency-dependent magnetization studies display a subtle susceptibility peak shift, indicating spin-glass-like behavior in V-doped samples.</span></div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39855-39865"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922928","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}

{"title":"Fabrication of Li4SiO4@Li2TiO3 core-shell tritium breeding materials with controlled thickness and improved moisture stability via a shrinkage matching process","authors":"Ruichong Chen ,&nbsp;Leiqing Tang ,&nbsp;Yi Zuo ,&nbsp;Jianqi Qi ,&nbsp;Wei Feng ,&nbsp;Haomin Wang ,&nbsp;Zhangyi Huang ,&nbsp;Tiecheng Lu","doi":"10.1016/j.ceramint.2025.06.215","DOIUrl":"10.1016/j.ceramint.2025.06.215","url":null,"abstract":"<div><div>In this study, a shrinkage matching process was developed to achieve synchronous shrinkage of Li₄SiO₄ and Li₂TiO₃<span> during sintering, enabling the successful fabrication of a core-shell structured tritium breeder material with a Li</span>₄SiO₄ core and Li₂TiO₃<span> shell to address the hygroscopicity of Li</span>₄SiO₄. The shell thickness of the Li₄SiO₄@Li₂TiO₃<span><span> core-shell breeding materials can be controlled in the range of 0–235 μm, and their moisture stability was systematically investigated at 10 % RH, 50 % RH, and 80 % RH. Results showed that increasing shell thickness significantly enhanced phase and mechanical stability in </span>humid environments, although excessively thick shells reduced overall Li content. To understand these improvements, the moisture stabilization mechanism of this core-shell breeding ceramics was comprehensively analyzed. Notably, the core-shell pebbles with a shell thickness of 146 μm exhibited a satisfactory crushing load (80.5 N) and a suitable Li content (16.87 wt%), and maintained superior moisture stability after storage at 80 % RH for 14 days. This novel concept, preparation route, and elucidated mechanism of utilizing Li</span>₂TiO₃ shell to enhance the moisture stability of Li₄SiO₄<span> matrix provide a new strategy for performance enhancement of advanced tritium breeding materials.</span></div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39801-39811"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921159","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}

{"title":"In-situ low-temperature synthesis of mullite whiskers from MoO3-doped industrial silica-alumina waste and growth kinetics study","authors":"Weilong Chen ,&nbsp;Xiaohua Gu ,&nbsp;Anyu Fan ,&nbsp;Heng Li ,&nbsp;Qingyong Su","doi":"10.1016/j.ceramint.2025.06.185","DOIUrl":"10.1016/j.ceramint.2025.06.185","url":null,"abstract":"<div><div><span>This study employed industrial silica-alumina waste residue as the principal raw material, achieving low-temperature synthesis of mullite whiskers through Al(OH)</span>₃ supplementation for silica-alumina ratio adjustment, with MoO₃<span><span> as the sole sintering aid<span>. An innovative conceptual design for exhaust gases recovery system was developed. The critical controlling factors and kinetic mechanisms governing whisker growth during low-temperature sintering were systematically investigated. Combined characterization techniques of X-ray diffraction analysis and scanning electron microscopy were employed to comprehensively analyze phase evolution patterns and </span></span>microstructural characteristics. Experimental optimization determined the optimal temperature range for whisker growth and the optimum MoO</span>₃<span><span><span> doping concentration. A physical model for whiskers agglomeration growth was established with corresponding formation mechanisms elucidated. Based on crystal growth theory and Arrhenius equation, </span>growth kinetic parameters along different </span>crystallographic orientations<span> were quantitatively characterized, with apparent activation energies calculated. Results demonstrated that MoO</span></span>₃<span> doping content significantly influenced phase purity and crystal morphology<span>, with excessive doping (&gt;7 wt%) inhibiting mullite crystal growth. Notably, MoO</span></span>₃<span><span> catalysis enabled mullite nucleation temperature reduction to 700 °C, with stable crystallization temperature range maintained at 800–850 °C. The doped system induced markedly </span>anisotropic<span> growth characteristics in mullite whiskers, resulting in a maximum whisker length of 12 μm and an aspect ratio of 11. At 850 °C, longitudinal growth activation energies measured 306.5, 184.8, and 229.5 kJ/mol for 4 wt%, 7 wt%, and 10 wt% MoO</span></span>₃<span> doping levels respectively, while transverse activation energies correspondingly reached 490.6, 658.7, and 671.6 kJ/mol. The activation energy differences confirmed the intrinsic crystallographic orientation-selective growth characteristics, highlighting the dual advantages of this process in low-temperature energy conservation and solid waste resource utilization.</span></div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39498-39510"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922243","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}

{"title":"Enhanced energy storage density and efficiency in A/B-site-engineered silver niobate ceramics","authors":"Renzhong Xue ,&nbsp;Xiaosong Liu ,&nbsp;Yuping Yang ,&nbsp;Xiang Zhu ,&nbsp;Haiyan Wang","doi":"10.1016/j.ceramint.2025.06.190","DOIUrl":"10.1016/j.ceramint.2025.06.190","url":null,"abstract":"<div><div><span>Lead-free silver niobate (AgNbO</span>₃, AN) ceramics have great potential in the pulse power equipment and other application fields due to fast charge and discharge speeds and high power density. However, their inferior energy storage density and efficiency limit their application. To address these issues, the cooperative optimization of A/B-sites in AN ceramics through Sm³⁺, Ca²⁺ and Ta⁵⁺ co-doping was performed in the present work. Such modification strategy inhibited the grain growth, while promoting the formation of a room-temperature M₂-M₃<span> phase boundary, enhancing the antiferroelectric stability and relaxation feature. The breakdown field strength increased from 210 kV/cm for AN to 394 kV/cm for Ag</span>_0.75Sm_0.05Ca_0.05Nb_0.9Ta_0.1O₃ ceramic. As a result, an ultrahigh energy storage density of 7.16 J/cm³ and a high efficiency of 81.2 % at 385 kV/cm along with excellent frequency, temperature and cycle stabilities were achieved in Ag_0.8Sm_0.04Ca_0.04Nb_0.9Ta_0.1O₃ ceramics. Therefore, this study demonstrates the effectiveness of comprehensive regulation of AN energy storage performance and its applicability for modern electrical and electronic equipment.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39549-39557"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922248","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}

{"title":"High thermoelectric performance in (Ga, Yb) Co-doped Bi2S3 bulks achieved by band structure and carrier concentration modulation","authors":"Ze-Yuan Yang,&nbsp;Qiu-Yu Luo,&nbsp;Chong-Yu Wang,&nbsp;Yang-Wei Wang,&nbsp;Jiang-Hu Yu,&nbsp;Xi Yan,&nbsp;Yi-Xin Zhang,&nbsp;Xing Yang,&nbsp;Jing Feng,&nbsp;Zhen-Hua Ge","doi":"10.1016/j.ceramint.2025.06.218","DOIUrl":"10.1016/j.ceramint.2025.06.218","url":null,"abstract":"<div><div>Due to their high abundance, low cost, and low toxicity, Bi₂S₃<span>-based thermoelectric materials without Te are significantly promising for eco-friendly and scalable applications. However, the ZT value of Bi</span>₂S₃<span>-based is not high enough and must be further improved. The rare-earth element doping is a promising strategy for synergistically enhancing the electrical and thermal transport properties. This study selected GaTe and YbBr</span>₃ for co-doping in Bi₂S₃<span><span> polycrystals<span><span> using a solid-state reaction and spark plasma sintering<span>, which enabled simultaneous modulation of the band structure and carrier concentration for significantly enhanced </span></span>thermoelectric and mechanical properties. Specifically, the synergistic optimization of electrical and </span></span>phonon transport was initially achieved through GaTe doping in Bi</span>₂S₃<span>, which effectively reduced the lattice thermal conductivity<span> while enhancing electrical conductivity. However, the improvement in thermoelectric performance with GaTe doping alone remained limited. Br substituted S to introduce extra electrons, while Yb replaced Bi to reduce the bandgap from 1.38 to 1.05 eV. The two effects synergistically optimized the electrical transport properties of the matrix. As a result, the optimized Bi</span></span>₂S₃ + 0.5 wt% GaTe +1.0 wt% YbBr₃ sample achieved an exceptional average power factor of 475.4 μW m⁻¹ K⁻²<span> over 323–773 K. Additionally, point defects<span><span>, dislocations, and micropores induced by the second phase contributed to strong phonon scattering, leading to a low lattice </span>thermal conductivity of 0.56 W m</span></span>⁻¹ K⁻¹ at 773 K. Consequently, a peak <em>ZT</em> value of 0.67 at 773 K and a high average <em>ZT</em> value of 0.45 over 323–773 K were achieved, which were relatively higher than other values reported in the literature. Furthermore, the mechanical properties were improved, with hardness increasing from 2.55 to 2.93 GPa, making Bi₂S₃ more deformation-resistant and durable. This study showed that co-doping rare earth elements was an effective approach for enhancing the thermoelectric and mechanical properties of the Bi₂S₃ material.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 23","pages":"Pages 39833-39842"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922578","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}