Ceramics International最新文献

{"title":"Synergistic regulation of lattice disorder and polar nanoregions through an antiferroelectric-to-relaxor transition in (1−x)NaNbO3–xSr0.7Bi0.2TiO3 ceramics for enhanced energy storage performance","authors":"Chenyang Zhang,&nbsp;Qiu Zhang,&nbsp;Liying Pan,&nbsp;Xueyue Lyu,&nbsp;Xinrui Wang,&nbsp;Jiawei Qi,&nbsp;Yuying Chang,&nbsp;Yutong Zhang,&nbsp;Guangdong Zhao","doi":"10.1016/j.ceramint.2026.07.339","DOIUrl":"10.1016/j.ceramint.2026.07.339","url":null,"abstract":"<div><div>Lead-free dielectric ceramics exhibiting both high recoverable energy density and ultrahigh efficiency are critically sought for advanced pulsed power applications; however, achieving these properties remains challenging due to inherent trade-offs among polarization difference, energy loss, and breakdown strength in conventional antiferroelectric systems. In this work, (1−<em>x</em>)NaNbO₃–<em>x</em>Sr₀.₇Bi₀.₂TiO₃ [(1−<em>x</em>)NN–<em>x</em>SBT] ceramics were successfully synthesized via a conventional solid-state method, and the composition–structure–property relationships were systematically elucidated. Structural characterizations indicate that increasing the SBT content induces a continuous transition from long-range antiferroelectric ordering to a relaxor state, accompanied by enhanced lattice disorder and the formation of polar nanoregions (PNRs), as confirmed by X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) analyses. Concurrently, significant grain refinement and improved microstructural homogeneity effectively enhance the breakdown strength. Consequently, the polarization behavior evolves from hysteretic domain switching to highly reversible PNR-dominated responses, resulting in markedly suppressed remnant polarization and an increased polarization difference (Δ<em>P</em>). As a result, the optimized compositions exhibit outstanding energy-storage performance, with a maximum recoverable energy density (<em>W</em>_rec) of 8.17 J/cm³ obtained at <em>x</em> = 0.7 and an ultrahigh energy-storage efficiency (<em>η</em>) of 99.8% achieved at <em>x</em> = 0.8 under a high breakdown strength of 620 kV/cm. Furthermore, the optimized ceramics exhibit excellent thermal stability over 20–140 °C, robust fatigue endurance up to 10⁵ cycles, and ultrafast discharge characteristics with a <em>t</em>_0.9 of approximately 50 ns, together with a high-power density. These superior performances are attributed to the synergistic effects of PNR-dominated dynamic polarization, suppressed long-range antiferroelectric ordering, and refined microstructure. This work provides a clear strategy for designing high-performance lead-free NaNbO₃-based dielectric capacitors through coordinated structural disorder and nanoscale polarization engineering.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 44608-44618"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174053","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":"Morphology induced enhancement in the functional properties of Ho2CoMnO6 double perovskite: From nanocrystalline to nanorod","authors":"K Pushpanjali Patra,&nbsp;V.M. Gaikwad,&nbsp;Pankaj N. Ukey","doi":"10.1016/j.ceramint.2026.07.442","DOIUrl":"10.1016/j.ceramint.2026.07.442","url":null,"abstract":"<div><div>In the present work, morphology-controlled Ho₂CoMnO₆ double perovskites were successfully synthesized in nanocrystalline (NC) and one-dimensional nanorod (NR) forms synthesized using gel combustion and hydrothermal routes respectively. Structural analysis using X-ray diffraction confirms that both samples crystallize in a monoclinic structure with P2₁/n space group. However, the nanorod morphology exhibits lattice distortion and modified octahedral tilting compared to the nanocrystalline counterpart. Electron microscopy reveals nearly spherical nanocrystalline particles with an average particle size of ∼160 nm, whereas the nanorods possess an average width of ∼71 nm with a preferential one-dimensional growth. High-resolution TEM and SAED analyses confirm the high crystallinity of the nanorods. X-ray photoelectron spectroscopy reveals the coexistence of mixed Co²⁺/Co³⁺ and Mn3+/Mn4+ oxidation states together with oxygen-defect-related species, indicating slight deviations from ideal oxygen stoichiometry. The nanorod sample exhibits a remarkable enhancement in the Curie temperature from approximately 83 K to 182 K compared with the nanocrystalline sample. This enhancement is attributed to the combined influence of an increased Co–O1–Mn bond angle, modified local oxygen environment, and morphology-induced changes in the local electronic structure. In addition, the nanorods display an antiferromagnetic transition near 97 K, a re-entrant spin-glass state around 31 K, and a clear field-cooled magnetic memory effect, indicating the presence of competing magnetic interactions and slow spin dynamics. Dielectric and impedance analyses reveal enhanced dielectric response and reduced activation energy (.1647 eV) compared with the nanocrystalline sample (.2051 eV), indicating facilitated thermally activated charge-carrier hopping. The correlation among structural distortion, mixed-valence states, oxygen-defect-related species, and magnetic exchange interactions demonstrates that morphology engineering effectively tunes the magnetic ordering, charge transport, dielectric relaxation, and nonequilibrium spin dynamics in Ho₂CoMnO₆ double perovskites, making the nanorods promising multifunctional materials for future magnetic and spintronic applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 45649-45666"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174060","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":"Grain-growth-controlled densification during reactive sintering of refractory Cr-substituted hollandite waste forms","authors":"Mingyang Zhao,&nbsp;Zhisen Feng,&nbsp;Yupeng Jiao,&nbsp;Xiao Chen,&nbsp;Linjue Xiao,&nbsp;Tao Hong,&nbsp;Zhenfeng Tong","doi":"10.1016/j.ceramint.2026.07.450","DOIUrl":"10.1016/j.ceramint.2026.07.450","url":null,"abstract":"<div><div>Cr-substituted hollandite ceramics are promising crystalline waste forms for immobilizing radioactive cesium, yet achieving high densification is challenging within temperature windows that mitigate Cs loss. Here, we develop a practical, sintering-aid-assisted reactive sintering route to densify Ba_0.667Cs_0.667Cr₂Ti₆O₁₆ at relatively low temperature and to identify the key factors controlling densification. Nine commonly used sintering aids were screened individually, and CuO was found to be uniquely effective. Guided by this screening, we correlate thermal behavior, crystallographic evolution, and microstructural development to clarify the role of CuO. Thermal analysis shows that CuO shifts BaCO₃-related mass-loss/endothermic events to a lower temperature, indicating earlier BaCO₃ decarbonation and CO₂ release. Rietveld refinement of the X-ray diffraction data further reveals systematic crystallographic evolution, consistent with limited Cu substitution and associated defect-compensation effects that may enhance mass transport. These effects coincide with a marked change in grain-growth behavior, where anisotropic growth is suppressed, and grains become more equiaxed, improving packing efficiency and enabling grain-growth-controlled densification. The resulting increase in relative density is accompanied by significantly reduced Cs release, indicating improved chemical durability. Overall, this work establishes CuO-enabled reactive sintering as a practical low-temperature processing strategy for refractory Cr-hollandite waste forms and highlights grain-growth control as a key microstructural mechanism linking processing, densification, and durability.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 45746-45759"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174128","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":"Regulation mechanism of different additives on the properties of solid waste-based foam glass-ceramics","authors":"Zhuyue Zhang,&nbsp;Lisi Liang,&nbsp;Zeming Wang,&nbsp;Jiajun Xi,&nbsp;Jiahui Chai,&nbsp;Zichen Wang","doi":"10.1016/j.ceramint.2026.07.428","DOIUrl":"10.1016/j.ceramint.2026.07.428","url":null,"abstract":"<div><div>Self-foaming foam glass-ceramics based on copper slag tailings and secondary aluminum dross face a critical bottleneck, high sintering temperatures make it difficult to achieve both low-temperature fabrication and high performance. To resolve this issue, four additives (SrF₂, CaF₂, SrO, and CeO₂) were selected to explore their regulatory effects and underlying mechanisms on foaming behavior, phase structure, and mechanical properties. SrF₂ was selected as the exploratory additive in this research, and a unified sintering benchmark of 1120 °C was established, which is 30 °C lower than that of the basic system. All four additives effectively promote self-foaming. As dosage rises, pore size and porosity increase monotonically, while bulk density and compressive strength decrease simultaneously. However, the regulatory intensity differs notably among the four additives. SrF₂ exhibits the optimal fluxing and foaming effect and can achieve significant lightweighting of the material. CaF₂ realizes balanced adaptation between lightweighting and mechanical properties. SrO can effectively maintain the integrity of the pore wall structure. CeO₂ possesses excellent pore homogenization control and matrix toughening effects. The major crystalline phase of all modified systems is diopside, with no detrimental impurity phases formed. Consistent with the established research consensus on silicate melt structure, anion type is the core factor determining the fluxing effect of the system, and fluorides exhibit significantly superior fluxing efficiency compared to oxides with the same cation. Environmental safety tests show that the leaching concentrations of fluoride ions in all samples are far below the national standard limits. This study provides a scientific basis for the low-temperature sintering and performance customized design of solid waste-based foam glass-ceramics, and opens up a new path for the large-scale and high-value utilization of metallurgical solid wastes.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 45510-45525"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174253","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":"Hydration behavior of silica gel/hydratable magnesium carboxylate binder for alumina-magnesia refractory castables","authors":"Luyan Sun,&nbsp;Donghai Ding,&nbsp;Guoqing Xiao,&nbsp;Jianjun Chen,&nbsp;Xin Deng,&nbsp;Zhenyu Lai","doi":"10.1016/j.ceramint.2026.07.437","DOIUrl":"10.1016/j.ceramint.2026.07.437","url":null,"abstract":"<div><div>The use of a silica gel/HMC binder has previously been proposed as a novel solution to improve the medium-temperature mechanical strength of hydratable magnesium carboxylate (HMC)-bonded alumina-magnesia refractory castables. However, the hydration mechanism of this binder remains insufficiently understood. The surface of the silica gel particles is covered with active groups (Si-OH), which can react with the hydrated ions derived from HMC to form new chemical bonds. In this study, silica gel/HMC binders are prepared by adding different amounts of silica gel (0.5 wt% to 2.0 wt%) to the castables. The hydration mechanism involves the formation of [Mg(H₂O)₆]₂(C₆H₆O₇)(H₃SiO₄)₂·nH₂O (Mcit-S-H gel) via a complexation reaction between the H₃SiO₄⁻ ions produced by nano silica gel and the [Mg(H₂O)₆]²⁺ ions and C₆H₆O₇²⁻ ions produced by the hydrolysis of HMC. At a silica gel content of 1.0 wt%, the hydration rate reaches its maximum, accompanied by the formation of well-developed interwoven strip-like Mcit-S-H gels that create a continuous three-dimensional network. The viscosity of the silica gel/HMC binder decreases by 28% compared to that of the HMC binder during the initial 27 min of hydration. Concurrently, the initial and final setting times are optimised at 40 min and 52 min, respectively. The green strength of the castables reaches 1.6 MPa.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 45601-45611"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174260","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 broadband microwave absorption in Sm-substituted Z-type Ba3Co2Fe24O41 hexaferrites via composition tuning","authors":"Cheng Qian,&nbsp;Qingzhe Yang,&nbsp;Chuangju Zhou,&nbsp;Kewei Zou,&nbsp;Weiwei Zhang,&nbsp;Qiangchun Liu,&nbsp;Min Zhang","doi":"10.1016/j.ceramint.2026.07.304","DOIUrl":"10.1016/j.ceramint.2026.07.304","url":null,"abstract":"<div><div>In this work, a series of Sm-substituted Ba_3-<em>x</em>Sm_<em>x</em>Co₂Fe₂₄O₄₁ (<em>x</em> = 0, 0.1, 0.15, 0.2, and 0.25) Z-type hexaferrites are synthesized via a sol-gel route. Phase analysis confirms that all samples crystallize in a single Z-type hexagonal structure without detectable impurity phases. By regulating the Sm substitution level, the magnetic properties and electromagnetic parameters of the hexaferrites are effectively tailored, leading to significantly enhanced microwave absorption performance. The saturation magnetization is improved upon Sm substitution, reaching 51.7 emu/g for the <em>x</em> = 0.2 sample, which is mainly attributed to the strengthened Fe³⁺-O-Fe²⁺ super-exchange interactions at the 12<em>k</em> and 2<em>b</em> crystallographic sites. Benefiting from optimized impedance matching and attenuation capability, the <em>x</em> = 0.2 sample exhibits the optimal comprehensive microwave absorption performance, delivering a minimum reflection loss (RL_min) of −57.4 dB at 12.08 GHz with an absorber thickness of 2.54 mm and an effective absorption bandwidth (EAB) of 7.84 GHz (7.04-14.88 GHz). When the thickness is slightly increased to 2.66 mm, the EAB is further broadened to 8.16 GHz (6.48-14.64 GHz), covering part of the C band, the entire X band, and part of the Ku band. For comparison, the <em>x</em> = 0.15 sample achieves an ultralow RL_min of −66.6 dB at 12.88 GHz with a thickness of 2.49 mm, but its broadband absorption performance is inferior to that of the <em>x</em> = 0.2 sample. The enhanced microwave absorption performance of the Sm-substituted hexaferrites is mainly attributed to the synergistic effects of improved impedance matching, enhanced dielectric loss associated with interfacial and dipolar polarization, and strengthened magnetic loss arising from natural and exchange resonances. These results demonstrate that Sm substitution is an effective strategy for achieving strong and broadband microwave absorption in Ba₃Co₂Fe₂₄O₄₁ Z-type (Co₂Z) hexaferrites.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 44191-44205"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174367","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 target composition control on the properties of IGZO thin films","authors":"Jie Chen,&nbsp;Ruolan Zhong,&nbsp;Chao Qi,&nbsp;Rui Du,&nbsp;Benshuang Sun,&nbsp;Shuhan Liu,&nbsp;Jilin He","doi":"10.1016/j.ceramint.2026.07.300","DOIUrl":"10.1016/j.ceramint.2026.07.300","url":null,"abstract":"<div><div>Unlike previous approaches that relied on tailoring sputtering processes to control film properties, in this study, powder metallurgy techniques were employed to fabricate four IGZO ceramic targets with distinct molar ratios (In₂O₃:Ga₂O₃:ZnO = 1:1:1, 1:1:2, 1:1:4, and 1:1:8, hereafter denoted as IGZO-111, IGZO-112, IGZO-114, and IGZO-118, respectively). The influence of target microstructure on the microstructure and optoelectronic properties of IGZO thin films deposited by magnetron sputtering was systematically investigated. Both the target and the resulting thin films were comprehensively characterized using multiple analytical techniques. The results indicate that the phase composition of the IGZO target (corresponding to In₂Ga₂ZnO₇, InGaZnO₄, InGaZn₂O₅, and InGaZn₄O₇) at different ratios significantly affects the deposition rate, crystalline state, surface morphology, optical bandgap, and electrical properties of the resulting thin films. With increasing Zn content in the target, the film deposition rate rises from 7.22 nm/min (IGZO-111) to 11.79 nm/min (IGZO-118), the optical bandgap decreases from 3.57 to 3.20 eV, and the resistivity increases from 3.91 × 10⁻¹ to 2.50 × 10² Ω cm. Films deposited using the IGZO-112 target exhibit optimal uniformity and density, featuring the lowest root-mean-square surface roughness (1.64 nm) and an average visible light transmittance of 89.34%. This study reveals the critical role of target composition and structural adjustment in optimizing the performance of IGZO thin films, providing essential guidance for material design in high-performance transparent oxide electronic devices.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 44139-44153"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174371","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":"Cerium dioxide nanoparticles reinforced 3D-printed BCP bioceramic scaffolds toward enhanced mechanical, antioxidant, and osteogenic activities","authors":"Jiaru Lu,&nbsp;Chonggui Li,&nbsp;Yilin Chen,&nbsp;Jiuxiao Li,&nbsp;Tonghe Zhu,&nbsp;Hongmei Zhang","doi":"10.1016/j.ceramint.2026.07.520","DOIUrl":"10.1016/j.ceramint.2026.07.520","url":null,"abstract":"<div><div>The repair of bone defects exceeding the natural regenerative capacity of bone remains a significant clinical challenge. Although various strategies have been explored, 3D-printed bioceramic scaffolds have emerged as a promising therapeutic solution. However, conventional bioceramics suitable for 3D printing often exhibit insufficient mechanical strength, limited antioxidant activity, and insufficient osteogenic activity. To overcome these limitations, three-dimensional (3D)-printed scaffolds were fabricated by incorporating cerium dioxide nanoparticles (CeO₂NPs) into biphasic calcium phosphate (BCP) bioceramics containing 70 wt% hydroxyapatite (HA) and 30 wt% β-tricalcium phosphate (β-TCP). This composite approach aimed to enhance both antioxidant activity and osteogenic differentiation. The physicochemical properties, antioxidant capacity, in vitro cellular responses, and osteogenic potential of the scaffolds were systematically assessed. Results demonstrated that scaffolds containing 10 wt% CeO₂NPs showed significantly improved mechanical and biological performance, particularly in antioxidant activity, compared to pure BCP scaffolds. Furthermore, a slight increase in microenvironmental pH induced by the BCP matrix may further enhance the antioxidant effects of CeO₂NPs and promote osteogenesis. This study presents a BCP-CeO₂ composite scaffold with dual functions of antioxidant activity and osteogenic induction. It highlights that integrating CeO₂NPs into BCP bioceramics via 3D printing technology holds promise for developing multifunctional scaffolds suitable for advanced bone tissue engineering applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 46547-46565"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174407","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":"Mechanical properties and the anomalous trade-off between ferroelectricity and electrostrain performance via Sm3+ A-/B-site substitution in KNN-based ceramics","authors":"Yongshang Tian,&nbsp;Chunying Liu,&nbsp;Yashan Li,&nbsp;Mengyao Chen,&nbsp;Yufei Wang,&nbsp;Yike Zheng,&nbsp;Xiongjie Hu,&nbsp;Qiangshan Jing","doi":"10.1016/j.ceramint.2026.07.317","DOIUrl":"10.1016/j.ceramint.2026.07.317","url":null,"abstract":"<div><div>Utilising the amphoteric doping behaviour of rare-earth ions to regulate defect chemistry is an effective strategy for enhancing the electrical properties of KNN-based lead-free piezoelectric ceramics. In this work, (1−<em>x</em>)K_0.5Na_0.5Nb_0.98Ta_0.02O₃-<em>x</em>Sm₂O₃ (KNNT-<em>x</em>Sm) ceramics were prepared using a conventional solid-state reaction. The effects of varying <em>x</em> on phase composition, average grain size, oxygen-vacancy concentration, and defect dipoles were systematically investigated, and the correlations of these properties with dielectric dispersion, ferroelectric relaxation, and electrostrain behaviour were explored. Key factors influencing Vickers hardness were also explored. The results showed that Sm³⁺ ions may modulate oxygen vacancy concentration and microstructure, thereby affecting the overall material performance. At <em>x</em> = 1.05 mol%, the ceramics exhibited excellent properties, including a remanent polarisation of 52.64 μC/cm², piezoelectric coefficient of 251.79 p.m./V, and Vickers hardness of 5.58 GPa. An anomalous trade-off between remanent polarisation and piezoelectric coefficient was observed and is suggested to be associated with changes in oxygen-vacancy concentration and defect dipoles arising from the site-occupancy transition of Sm³⁺ ions. Furthermore, the Vickers hardness of KNNT-<em>x</em>Sm ceramics appears to be primarily governed by lattice energy and microstructure. This study provides valuable insights into the optimisation of rare-earth-doped KNN-based piezoceramics.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 44364-44374"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174498","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":"Red mud incorporated alkali-activated metakaolin materials with enhanced photon and electron attenuation","authors":"Taha Erdogan,&nbsp;Cansu Kurtulus,&nbsp;Meryem Cansu Sahin,&nbsp;Recep Kurtulus","doi":"10.1016/j.ceramint.2026.07.372","DOIUrl":"10.1016/j.ceramint.2026.07.372","url":null,"abstract":"<div><div>The development of sustainable radiation shielding materials has gained increasing attention due to the environmental and health concerns associated with conventional lead- and cement-based systems. In this study, red mud (RM), a highly alkaline industrial waste generated during alumina production, was utilized as a functional additive in metakaolin (MK)-based alkali-activated composites to develop environmentally friendly shielding materials with improved photon and electron attenuation capability. Four different RM-MK compositions were synthesized and systematically characterized in terms of structural, thermal, morphological, mechanical, and radiation attenuation behavior. Increasing RM incorporation significantly improved the density and compressive strength of the composites, increasing these values from 1.69 to 1.83 g cm⁻³ and from 14 to 43 MPa, respectively. XRD, FTIR, SEM/EDS, TGA/DSC and water absorption analyses revealed that RM addition increased that RM addition preserved the dominant amorphous aluminosilicate structure while reducing water absorption from 21.44% to 16.06%, indicating a less permeable and apparently more compact matrix despite the increased chemical heterogeneity. Gamma-ray attenuation performance was experimentally investigated at 356, 662, 1173, and 1332 keV using a NaI(Tl)-based gamma spectrometry system and further validated through Phy-X/PSD calculations and GAMOS Monte Carlo simulations. RM-rich composites exhibited higher attenuation coefficients together with lower HVL, TVL, and MFP values. Among all compositions, the MK60 sample demonstrated the best shielding performance because of its increased density and Fe-rich phase content. Electron attenuation behavior was also experimentally evaluated under clinical linear accelerator conditions within the 4-18 MeV range and compared with Eclipse Monte Carlo calculations. The results demonstrate that RM can effectively enhance radiation attenuation performance in alkali-activated matrices while simultaneously enabling sustainable waste utilization.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"52 25","pages":"Pages 44974-44988"},"PeriodicalIF":6.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149174619","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}