Journal of the American Ceramic Society最新文献

{"title":"Synergistic Improvement in Mechanical and Thermal Properties of VPP-Printed AlN via Mg(H2PO4)2 Bonding Densification","authors":"Guangyi Liu,&nbsp;Zhifeng Huang,&nbsp;Tingxi Pu,&nbsp;Binhua Xiang,&nbsp;Yizhen Chu,&nbsp;Qinggang Li,&nbsp;Qiang Shen,&nbsp;Fei Chen","doi":"10.1111/jace.71041","DOIUrl":"https://doi.org/10.1111/jace.71041","url":null,"abstract":"<div>\u0000 \u0000 <p>Digital light processing shows significant potential for fabricating AlN ceramics with complex geometries. However, porosity formed during the debinding stage remains the primary factor limiting the relative density of the material. This work uses magnesium dihydrogen phosphate (Mg(H₂PO₄)₂) as an additive to solve densification problem of DLP printed AlN ceramics. We found Mg(H₂PO₄)₂ can shorten the distance between AlN particles to promote densification during the printing and debinding stages. And Mg(H₂PO₄)₂ can further react with residual alumina to form a small amount of magnesium aluminum spinel (MgAl₂O₄) and reduce the content of oxygen impurities during the sintering stage. With the addition of 7% Mg(H₂PO₄)₂, the mechanical and thermal properties of the AlN ceramics were significantly enhanced. The sample achieved a curing depth of 94 µm when printed with a slurry of 55% solid loading. The bending strength is 387.9 MPa, the thermal conductivity is 183.9 W/(m × K), the relative density is 99.5 ± 0.1% and the porosity is 0.5% ± 0.1% when sintered at 1850°C. Moreover, after 20 thermal cycles (400°C), the printed sample retained a high bending strength of 334.0 MPa. This work solved the problem of relatively low density by adding Mg(H₂PO₄)₂, laying the foundation for further improvement of its mechanical and thermal properties.</p>\u0000 </div>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Performance Phosphor-in-Glass Film on Grating Structure Sapphire Substrate for Laser Lighting","authors":"Mingchao Fang,&nbsp;Wenting Ding,&nbsp;Cihao Huang,&nbsp;Baoping Zhang,&nbsp;Yang Mei,&nbsp;Leiying Ying,&nbsp;Daquan Yu,&nbsp;Rongbin Xu","doi":"10.1111/jace.71044","DOIUrl":"https://doi.org/10.1111/jace.71044","url":null,"abstract":"<div>\u0000 \u0000 <p>Laser lighting has the advantages of ultra-high brightness and luminous efficiency in the field of solid-state lighting. As one of the luminescence color converters for white laser lighting, phosphor-in-glass film (PiF) based on sapphire substrate is attracting much attention. In this work, a grating structure sapphire substrate (GS) with convex cross-section was fabricated. PiFs, consisting of melted silicon borate glass matrix and Y₃Al₅O₁₂:Ce³⁺ phosphor powder, were prepared either on the same side (PiF-GS-S) or the opposite side (PiF-GS-O) of GS. Compared with PiF on planar sapphire (PiF-F), the incident blue laser beam is modulated by the pattern on the GS, which refracts the light and causes divergence of the laser beams. This expands the laser spot on the PiF, improving the uniformity of the laser beams. The saturation luminous flux of the PiF-GS-O under the 14.48 W/mm² laser excitation (1446 lm) is 49.7% higher and has a lower maximum temperature than those of the PiF-F, while maintaining a high luminous efficiency (150 lm/W). In addition, the effects of the two sintering methods on laser refracting are comparatively analyzed. The results demonstrate that the laser spot can be enlarged and homogenized by patterning the sapphire substrate, which finally helps to achieve higher luminous flux, higher luminous efficiency, and higher saturation threshold for laser lighting.</p>\u0000 </div>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toughening of TiO2 via Femtosecond Laser Shock Peening","authors":"Anish Bajla,&nbsp;Shubha Majumder,&nbsp;Subah Mubassira,&nbsp;Ke Xu,&nbsp;Xuanyu Sheng,&nbsp;Joshua A. Medina,&nbsp;Het Jani,&nbsp;Colin McMillen,&nbsp;Luiz G. Jacobsohn,&nbsp;Haiyan Wang,&nbsp;Xinghang Zhang,&nbsp;Shuozhi Xu,&nbsp;Xin Zhao,&nbsp;Yifan Zhang","doi":"10.1111/jace.71037","DOIUrl":"https://doi.org/10.1111/jace.71037","url":null,"abstract":"<p>Most ceramics have low fracture toughness (&lt;5 MPa <span></span><math>\u0000 <semantics>\u0000 <msqrt>\u0000 <mi>m</mi>\u0000 </msqrt>\u0000 <annotation>$sqrt{m}$</annotation>\u0000 </semantics></math>) at room temperature. This work explores the feasibility of toughening TiO₂ via femtosecond laser shock peening (fs-LSP). Transmission electron microscopy (TEM) analyses reveal LSP-induced the creation of high-density stacking faults, dislocation structures, and twin boundaries in the LSP-treated surface layer (∼55 µm thick) of single-crystal rutile TiO₂. Meanwhile, oxygen vacancies were introduced into TiO₂ via the LSP treatment, as evidenced by X-ray photoelectron spectroscopy (XPS) results and the red peak shifts in Raman spectra. In addition, X-ray diffraction scans show in-plane compressive residual stress (−61 to −306 MPa) built in LSP-processed TiO_2. The indentation fracture resistance (<i>K_IFR</i>) of TiO₂ is enhanced from 2.8 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>MPa</mi>\u0000 <msqrt>\u0000 <mi>m</mi>\u0000 </msqrt>\u0000 </mrow>\u0000 <annotation>${rm MPa}sqrt m $</annotation>\u0000 </semantics></math> to 6.8–8.2 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>MPa</mi>\u0000 <msqrt>\u0000 <mi>m</mi>\u0000 </msqrt>\u0000 </mrow>\u0000 <annotation>${rm MPa}sqrt m $</annotation>\u0000 </semantics></math>. The role of compressive residual stress, oxygen vacancy, dislocations, stacking faults, and twins are discussed using atomistic simulations, semiquantitative and qualitative analyses. This study demonstrates the remarkable synergistic effects of defect networks and residual compressive stress in toughening TiO₂ and possibly other ceramic materials. Our work also qualifies the fs-LSP as an effective and scalable method to toughen ceramic materials.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jace.71037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoluminescence Properties of Sm3+-Activated Na3Ba2Ca(PO4)3 Orange-Red Phosphor With High Color Purity for White LEDs","authors":"Jin Zhao,&nbsp;Yongcheng Fu,&nbsp;Yu Wang,&nbsp;Funi Liu,&nbsp;Ruting Tu,&nbsp;Yongchun Zhang,&nbsp;Jingwen Lu,&nbsp;Nazi Zhong,&nbsp;Zhihua Leng","doi":"10.1111/jace.71051","DOIUrl":"https://doi.org/10.1111/jace.71051","url":null,"abstract":"<div>\u0000 \u0000 <p>A series of Na₃Ba₂Ca(PO₄)₃: <i>x</i>Sm³⁺ (<i>x</i> = 0.01–0.13) orange-red phosphors was synthesized via a high-temperature solid-state reaction. X-ray diffraction (XRD) analysis confirmed that all samples were phase-pure. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) mapping revealed a homogeneous distribution of constituent elements throughout the particles. Under near-ultraviolet excitation at 401 nm, the phosphors exhibited bright orange-red emission with the strongest peak at 596 nm, corresponding to the characteristic ⁴G_5/2 → ⁶H_7/2 transition of Sm³⁺. The Commission Internationale de l’Éclairage (CIE) chromaticity coordinates of all samples fell in the orange-red region. Moreover, the phosphor demonstrated favorable thermal stability, retaining 85.9% of its initial emission intensity at 423 K. A white light-emitting diode was fabricated by combining the optimal phosphor with a near-UV LED chip, yielding white light with CIE chromaticity coordinates of (0.3267, 0.3879) and a correlated color temperature of 5763 K. These results indicate that Na₃Ba₂Ca(PO₄)₃: Sm³⁺ is a promising candidate for near-UV-excited white light-emitting diodes.</p>\u0000 </div>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resolving Basis Dependence in Point-Defect Scattering Models for Thermal Conductivity in Multi-Sublattice Ceramics","authors":"Yinglu Tang,&nbsp;Junsu Kim,&nbsp;Heechan Sang,&nbsp;Prakhar Jindal,&nbsp;Botchu Jyoti,&nbsp;Hyunsik Kim","doi":"10.1111/jace.70995","DOIUrl":"https://doi.org/10.1111/jace.70995","url":null,"abstract":"<p>Alloying is a widely used strategy for reducing lattice thermal conductivity through phonon scattering induced by mass and strain fluctuations. However, the evaluation of disorder-scattering parameters in multi-sublattice compounds remains inconsistent because both atomic- and unit-cell-based formulations are used in the literature. In this work, the origin of these discrepancies is systematically examined using ZrC and ZrB₂ as model systems. We show that the two approaches yield equivalent predictions only when a consistent basis is maintained throughout the calculation and the alloyed site has a degeneracy of unity. For compounds containing multiple sublattices or higher site degeneracy, the formulations diverge and can lead to substantially different estimates of alloying-induced phonon scattering. To address this issue, a generalized framework incorporating sublattice-selective disorder scattering is proposed. The formulation preserves basis consistency while accounting for the localized nature of disorder in complex compounds. The model is applied to W-doped ZrB₂ ceramics and compared with experimental thermal conductivity measurements. Improved agreement is obtained relative to conventional treatments. The proposed framework provides a physically consistent methodology for evaluating point-defect scattering in multi-sublattice solid solutions and enables more reliable prediction of lattice thermal conductivity in complex ceramic materials.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jace.70995","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upcycling Solar Glass Into Ce-Doped Oxyfluorides: Spectroscopic and Crystallization Properties","authors":"Marcos Paulo Belançon,&nbsp;Rafaela Valcarenghi,&nbsp;Marcelo Sandrini,&nbsp;Brenno Silva Greatti,&nbsp;Robson Ferrari Muniz,&nbsp;Vitor Santaella Zanuto,&nbsp;Sandra Ory,&nbsp;Aurélien Canizares,&nbsp;Maxence Vigier,&nbsp;Emmanuel Veron,&nbsp;Mathieu Allix,&nbsp;Michael Pitcher","doi":"10.1111/jace.71035","DOIUrl":"https://doi.org/10.1111/jace.71035","url":null,"abstract":"<p>Oxyfluorides containing up to 75 wt% of recycled glass from end-of-life solar panels have been investigated. Reduced processing temperature and high transparency have shown that the material has potential for optical applications. In this work, cerium-doped samples were investigated. Spectroscopic study reveals the presence of <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>Ce</mi>\u0000 <mrow>\u0000 <mn>3</mn>\u0000 <mo>+</mo>\u0000 </mrow>\u0000 </msup>\u0000 <annotation>${rm Ce}^{3+}$</annotation>\u0000 </semantics></math>, and luminescence from these ions and oxygen-deficient centers was detected. Raman demonstrated that cerium affects the glass network by promoting polymerization. In turn, thermal analysis indicated some changes in the crystallization events between 500<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow></mrow>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <annotation>$^{circ }{rm C}$</annotation>\u0000 </semantics></math> and 800<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow></mrow>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <annotation>$^{circ }{rm C}$</annotation>\u0000 </semantics></math>, which were confirmed by in situ X-ray powder diffraction measurements. Crystallization of fluorite, xonotlite, and combeite was confirmed, while other phases give minor contributions to the XRD patterns. Cerium addition reduced the formation of xonotlite, mainly above 700<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow></mrow>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <annotation>$^{circ }{rm C}$</annotation>\u0000 </semantics></math>. The potential applications of the material and the further studies required are discussed.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jace.71035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural Evolution and Mechanical Properties Enhancement of B4C Ceramics via BN-Coated Powder Design","authors":"Chao Pan,&nbsp;Aiyang Wang,&nbsp;Wen Zhang,&nbsp;Fangze Chen,&nbsp;Qianglong He,&nbsp;Huan Wang,&nbsp;Lin Ren,&nbsp;Weimin Wang,&nbsp;Fan Zhang,&nbsp;Zhengyi Fu","doi":"10.1111/jace.71043","DOIUrl":"https://doi.org/10.1111/jace.71043","url":null,"abstract":"<div>\u0000 \u0000 <p>This study presents a CVD synthesis strategy for BN-coated B₄C powder synthesis employing controlled nitridation of B₄C in an NH₃ atmosphere for achieving a homogeneous hexagonal BN distribution in B₄C/BN ceramics. Systematic temperature modulation (600°C–1200°C) led to different thickness progression with concurrent structural evolution from amorphous to turbostratic BN configurations, ultimately forming nanoflower-like architectures. BN facilitated particle rearrangement through its lubricative two-dimensional interlayers and induced phase transformation, which in turn reduced the densification temperature by 150°C. The composite nitrided at 800°C (B₄C@BN08) exhibited superior comprehensive performance with a flexural strength, fracture toughness, and bulk density of 627 ± 41 MPa, 5.01 ± 0.17 MPa·m^1/2, and 2.467 g/cm³, respectively. Mechanistic analyses revealed that this synergistic strengthening originated from BN nanosheet-induced crack deflection/branching and pinning effect as well as high-density defects at B₄C and BN grains. These findings establish microstructure-property relationships critical for designing next-generation lightweight ceramic composites.</p>\u0000 </div>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 8","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spark Plasma Sintering of Si3N4–BN Ceramic Composites With Improved Properties","authors":"Dengke Zhao,&nbsp;Binbin Fan,&nbsp;Shuo Zhao,&nbsp;Bohan Wang,&nbsp;Yiyao Ge,&nbsp;Kexin Chen,&nbsp;Guanghua Liu","doi":"10.1111/jace.70975","DOIUrl":"https://doi.org/10.1111/jace.70975","url":null,"abstract":"<div>\u0000 \u0000 <p>Si₃N₄–BN composites were fabricated by spark plasma sintering, and the effects of starting BN particle sizes on microstructure, mechanical properties, and thermal shock resistance of the composites were systematically investigated. The samples with submicron BN effectively refined <i>β</i>-Si₃N₄ grains, resulting in enhanced mechanical properties, including flexural strength and hardness. Among all samples, the 800-S7B2 sample exhibited the optimal combination of properties, with a flexural strength of 1008 ± 49 MPa, fracture toughness of 6.8 ± 0.1 MPa·m^1/2, and hardness of 8.1 ± 0.1 GPa. Thermal shock tests indicated that both the samples with submicron BN and the samples with microscale BN retained approximately 90% of their residual flexural strength after thermal shock at 1200°C. Notably, the samples with microscale BN exhibited higher R^IV and α_cr values due to their greater fracture toughness-to-strength ratio, enhancing resistance to crack propagation and resulting in superior thermal shock performance, with residual flexural strength exceeding 90% after thermal shock at 1200°C. These results demonstrate that controlling the BN particle size is an effective strategy to optimize the microstructure, mechanical performance, and thermal shock resistance of Si₃N₄–BN composites.</p>\u0000 </div>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 7","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148386122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental Barrier Coatings Deposited by Suspension Plasma Spraying","authors":"Dapeng Zhou,&nbsp;Emine Bakan,&nbsp;Yoo Jung Sohn,&nbsp;Weijie Dong,&nbsp;Robert Vassen","doi":"10.1111/jace.70976","DOIUrl":"https://doi.org/10.1111/jace.70976","url":null,"abstract":"<p>Fully crystalline, dense environmental barrier coatings (EBCs) are required to protect SiC-based ceramic matrix composites, which are the advanced structural materials for hot-section components of gas turbines. Thermal spray technologies, which have been widely used for depositing thermal barrier coatings, are also applied to deposit EBCs. Avoiding the segmental cracks is one of the main challenges in depositing thermal sprayed EBCs. In this work, suspension plasma spraying (SPS) was used to deposit EBCs on the SiC substrates. The combustion of an ethanol-based suspension can bring plasma additional enthalpy. As a result of that, extremely high deposition temperatures (above 1200°C) could be achieved. At such high deposition temperatures, fully crystalline crack-free Yb₂Si₂O₇ coatings were successfully obtained. However, A relatively high amount of Yb₂SiO₅ phase was observed in the as-sprayed coatings. The high amount of the Yb₂SiO₅ phase was attributed to the high surface ratio of the particles formed during the suspension plasma spray.</p>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 7","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jace.70976","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148386123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Photoluminescence of Eu3+-Activated and Eu3+/Eu2+ Co-Activated Li4Al4B6O17​ Phosphors","authors":"Yanlin Huang,&nbsp;Zihan Qiao,&nbsp;Xifeng Yang,&nbsp;Junyu Lv,&nbsp;Donglei Wei,&nbsp;Hyun Kyoung Yang","doi":"10.1111/jace.70974","DOIUrl":"https://doi.org/10.1111/jace.70974","url":null,"abstract":"<div>\u0000 \u0000 <p>Eu³⁺-doped and Eu^2+/3+ co-doped Li₄Al₄B₆O₁₇​ were synthesized by a high-temperature solid-state reaction under air and reducing atmospheres, respectively. The phase purity, crystal structure, and elemental composition were investigated. Under ultraviolet light excitation, the Eu³⁺-only sample exhibits intense orange‒red luminescence dominated by the ⁵D₀ → ⁷F₁ magnetic dipole transition _​ at 592 nm, suggesting that Eu³⁺ centers may occupy high-symmetry sites, possibly with an inversion center, although the precise crystal structure of the host remains unknown. Li₄Al₄B₆O₁₇:Eu prepared under a reducing atmosphere shows luminescence from both Eu²⁺ and Eu³⁺ centers, which was confirmed by XPS and decay kinetics. At a low doping concentration (<i>x</i> = 0.005), complete reduction to Eu²⁺ was achieved, giving a broad blue emission band centered at 470 nm. With increasing Eu concentration (<i>x</i> ≥ 0.01), residual Eu³⁺ appears, and the energy transfer from Eu²⁺ to Eu³⁺ was evidenced by excitation spectra and decay dynamics. Temperature-dependent luminescence reveals good thermal stability with an activation energy of approximately 0.40 eV for both Eu³⁺ and Eu²⁺ emissions. The internal quantum efficiency reaches 37.5% for the Eu³⁺-only sample, while the co-doped sample exhibits a lower efficiency of 17.5%, which is attributed to defect-related non-radiative losses arising from heterovalent ion substitution. This work provides a comprehensive understanding of the luminescence mechanisms in Eu-doped Li₄Al₄B₆O₁₇, which features a rigid aluminum borate framework with Li⁺ as the only cation site. This study serves as a reference for rare-earth luminescence in such Li-only hosts.</p>\u0000 </div>","PeriodicalId":200,"journal":{"name":"Journal of the American Ceramic Society","volume":"109 7","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148386112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}