Ceramics doi: 10.3390/ceramics9050050

Authors: Sohaib Fadhil Mohammed Mohd Firdaus Yhaya Matheel Al-Rawas Tahir Yusuf Noorani

The use of zirconia as a material in the base of modern restorative dentistry is due to its high strength, biocompatibility, and improved aesthetic performance. The aim of this review is to provide an integrated and coherent overview of the recent developments in zirconia crowns by focusing on the development of materials, microstructure, digital fabrication processes, optical capabilities, and clinical performance. A survey of literature in the form of a narrative literature review was conducted in the most significant databases, such as PubMed, Scopus, Web of Science, and Google Scholar, including publications published since 2000, with a focus on systematic reviews, meta-analyses, clinical studies, and materials science studies. The results show that zirconia materials have developed beyond traditional 3Y-TZP systems, characterized by high strength and fracture toughness to high-translucency and multilayer zirconia (4Y 6Y-PSZ) systems, which provide better aesthetics at the cost of lower mechanical reliability. The implementation of CAD/CAM technologies has enhanced the accuracy of fabrication, marginal fit and reproducibility and the development of sintering, surface modification and bonding protocols has enhanced clinical performance. Recent clinical results have shown high survival rates (around 85–95 percent over 5–10 years), and the results depend on the design of the restoration, the zirconia generation, and the functional loading circumstances. Despite these developments, there are still concerns about the durability of bonding, trade-offs between translucency and strength, and long-term performance of high-translucency zirconia. The development of new technologies, such as additive manufacturing, design-aided artificial intelligence, and bioactive surface modification, is a promising avenue toward improving clinical reliability and performance.

Ceramics doi: 10.3390/ceramics9050049

Authors: Akio Ikesue Yan Lin Aung

Fully dense monoclinic zirconia ceramics were successfully fabricated by pressureless sintering and/or HIP. Although monoclinic zirconia exhibits unique physicochemical properties, fabrication of fully dense polycrystalline bodies has remained challenging due to catastrophic volume expansion during the tetragonal-to-monoclinic transformation. By introducing a synergistic ternary (Ga2O3-ZnO-TiO2) sintering aid, a relative density exceeding 99.6% with an average grain size of 0.5–2 µm was achieved by sintering under an oxygen atmosphere at 1070 °C for 3–100 h, well below the phase-transition temperature. X-ray diffractometry confirmed a single-phase monoclinic structure. Subsequent hot isostatic pressing at 1080 °C and 180 MPa for 2 h eliminated residual porosity, yielding a 4-point bending strength of 328 MPa, a fracture toughness of 2.7 MPa·m0.5, and a Vickers hardness HV1 of 805. This monoclinic zirconia ceramic exhibited ~30% total transmittance, while in-line transmittance remained below 0.1% due to intrinsic birefringence of the monoclinic lattice. These results established a low-temperature route for densifying phase-sensitive ceramics while achieving long-term stability.

Ceramics doi: 10.3390/ceramics9050048

Authors: Mahesh Kumar Munchikana Shivakumar Jagadish Shetty Anbukkarasi Rajendran Gurumurthy Sangam Chandrashekar Manjunath Shetty Tarun Sharda Raghavendra Karkala Gururaj

The structural response of ceramics to extreme deformation is of significant scientific and technological relevance since such conditions are commonly encountered during both processing and service. In this study, monoclinic zirconia was subjected to high-energy ball milling for extended durations of 80 h and 120 h, followed by annealing at 1000 °C. X-ray diffraction revealed a progressive increase in the tetragonal phase content with milling duration, while subsequent annealing promoted its consolidation alongside the principal monoclinic phase, resulting in a stable biphasic structure. The phase evolution is also evaluated through a Raman spectroscopy analysis and correlated with the morphology, mechanical properties, and surface area analyses. Scanning electron microscopy confirmed the preservation of nanoscale features in the milled and annealed specimens, in contrast to the unmilled sample, which exhibited pronounced grain coarsening. The combined presence of nanostructural stability and biphasic phase constitution underscores the efficacy of high-energy ball milling, in conjunction with thermal treatment, as an effective strategy to tailor the microstructure and phase stability of zirconia ceramics for advanced engineering applications.

Ceramics doi: 10.3390/ceramics9050047

Authors: Andrey V. Poligenko Evgeny A. Ruban Kirill M. Osipov Andrey A. Shaporenkov Vladimir V. Dushik

In this study, a multiphysics finite-element model was developed for the deposition of W–C–B coatings in a hot-wall tubular CVD reactor from a gas mixture of tungsten hexafluoride (WF6), hydrogen (H2), and trimethylamine borane ((CH3)3N:BH3) at 550 °C and 5 Torr. The aim of this work is to deepen the understanding of reactant transport mechanisms and to optimize the process parameters for obtaining targeted tungsten carbide or boride phases. The simulations were performed in COMSOL Multiphysics (ver. 6.1) using a 2D axisymmetric formulation that couples laminar flow, heat transfer, and multicomponent diffusion, accounting for heterogeneous chemical reactions at the reactor walls. The obtained spatial distributions of reactant concentrations demonstrate precursor depletion along the reactor length. A comparison of the calculated B/W and C/W stoichiometric ratios for 13 operating conditions with experimental data confirms a transition from W and W–B phases at low trimethylamine borane (TMAB) flow rates to tungsten carbide-based coatings at higher flow rates. Furthermore, a parametric sweep was utilized to determine the optimal parameter range for the synthesis of tungsten borides.

Ceramics doi: 10.3390/ceramics9050046

Authors: Mohammod Hafizur Rahman

Ceramic membranes show potential for high-temperature CO2 extraction from flue gas; nevertheless, their performance under simultaneous heat and pressure stress is not well comprehended. This research addresses the temperature-dependent CO2/N2 separation characteristics of a commercial ceramic membrane (pore size ~0.1–1 µm) utilizing simulated flue gas (11.8% CO2, 74.2% N2, 2.5% O2, remainder CH4) at temperatures ranging from 60 to 140 °C and pressures between 4 and 6 bar. Calibrated GC-TCD was used to quantify permeate compositions across multiple operating valve openings. With a CO2/N2 selectivity (α) of 0.75 at 4 bars, the maximum CO2 enrichment peaked at 80 °C (10.8 mol%), getting close to the Knudsen diffusion limit (0.80). Selectivity decreased dramatically beyond 100 °C—α = 0.61 (100 °C), 0.45 (140 °C)—and CO2 dropped to 5.8% at 4 bar and 2.2% at 6 bars. Viscous flow dominance was shown by the strong pressure amplification—α decreased by more than 60% from 4 to 6 bar at all temperatures. These findings emphasize the possibility of performance collapse in hot, pressured flue streams and identify the limited operating window under which Knudsen-controlled transport can be maintained. The study provides quantitative evidence of a transition in transport regime under mixed flue-gas conditions.

Ceramics doi: 10.3390/ceramics9050045

Authors: Zhuo Chen Peng He Yueyue Wang Qingqing Zhou Feng Tao Qi Liu Yuexin Liu

MXenes, with a high surface area, abundant active sites, and excellent ion transport properties, have demonstrated excellent electrochemical performance. However, systematic comparisons of the structural evolution process and electrochemical performance for MXene are lacking. In this study, multilayer MXene (M-Ti3C2Tx) was successfully fabricated by in situ etching. During the subsequent centrifugation process, the thicker and heavier multilayer sheets settled due to their faster sedimentation rate, while the lighter, surface-functionalized monolayer sheets remained colloidally stable in the supernatant due to solvation and electrostatic repulsion, thereby achieving separation and obtaining delaminated MXene (D-Ti3C2Tx). Structural analysis indicates that the removal of the aluminum layer synergizes with the exfoliation of the nanosheets, significantly increasing the interlayer spacing and making the sheet structure more pronounced, and the pore structure is more abundant. Especially, in three-electrode and two-electrode systems at an identical mass loading of 5 mg on carbon paper, D-Ti3C2Tx delivered a higher specific capacitance, more pronounced pseudocapacitive behavior, and a superior rate capability compared to Ti3AlC2 and M-Ti3C2Tx. Such excellent electrochemical performance of D-Ti3C2Tx is due to the shortened ion diffusion path in the delaminated structure, which enables rapid ion migration, an extremely large specific surface area, and a mesoporous structure that provides abundant active sites. This study underscores the significant potential of D-Ti3C2Tx in emerging energy storage systems and offers insights into guiding MAX phase synthesis during its preparation.

Ceramics doi: 10.3390/ceramics9050044

Authors: Zaeem Ur Rehman Muhammad Faheem Maqsood Mohsin Ali Raza Syed Muhammad Zain Mehdi Rumasa Kanwal Umair Azhar Sunil Kumar Muhammad Javaid Iqbal Waseem Amin Muhammad Farooq Khan Sharafat Ali

The effect of A-site substitution on the morphological and electrochemical properties of La1-xSrxMnO3 (x = 0, 0.25, 0.50) perovskites was investigated to evaluate their potential as electrode materials for supercapacitors. X-ray diffraction analysis confirmed the formation of the perovskite structure, with minor peak shifts and distortion of crystal structure induced by Sr substitution. Scanning electron microscopy analysis revealed irregularly shaped particulate morphology across all perovskite compositions. The increasing amount of Sr as in La0.5Sr0.5MnO3 (LSM-50) favored the formation of nanosized particles, and energy dispersive X-ray (EDX) analysis confirmed the presence of all constituent elements; EDX elemental mapping also showed a uniform distribution of all elements in the various perovskite compositions. Among all compositions, La0.75Sr0.25MnO3 (LSM-25) possessed the highest specific capacitance (Csp) of 483 Fg−1 at 1 Ag−1 current density in 3 M KOH electrolyte, as determined by electrochemical analysis. This perovskite material also exhibited a capacitance retention of 87.8% after 5000 charge–discharge cycles. Electrochemical impedance spectroscopy revealed that LSM-25 showed the lowest solution resistance (0.68 Ω*cm2) and charge transfer resistance (1.52 Ω*cm2), indicating strong electrode–electrolyte interaction. Detailed analysis of cyclic voltammetry data revealed that the predominant charge storage mechanism was diffusive in nature, with 88% of the diffusive contribution registered for LSM-25. These findings demonstrate that Sr substitution at the A-site significantly enhances the energy storage performance of LaMnO3, making it a promising candidate for supercapacitor applications.

Ceramics doi: 10.3390/ceramics9050043

Authors: Subin Antony Jose John Crosby Pradeep L. Menezes

Ceramics are widely evaluated for their extreme hardness, high-temperature stability, and corrosion resistance, which enable applications in harsh service environments. However, these same properties, high melting points, brittleness, and low thermal shock resistance, make conventional manufacturing of complex ceramic components difficult and expensive. Traditional processes often require costly diamond tooling or energy-intensive sintering and tend to produce only simple geometries, with significant waste material and risk of defects. Additive manufacturing (AM) has recently emerged as a promising route to fabricate intricate, near-net-shape ceramic parts without these drawbacks. By building components layer by layer, AM reduces the need for extensive machining and enables the fabrication of geometrically complex, near-net-shape ceramic structures with reduced material waste, although challenges such as porosity, interlayer defects, and cracking during post-processing remain. Nonetheless, ceramic AM technologies lag behind their metal and polymer counterparts, and significant challenges remain in achieving fully dense parts with reliable mechanical properties. This review provides an in-depth overview of the state of the art in ceramics and ceramic composite additive manufacturing. We detail the most widely used AM processes (stereolithography, binder jetting, material extrusion, powder bed fusion, inkjet printing, and direct energy deposition) and typical feedstock formulations for each technique. We examine the resulting mechanical properties (strength, toughness, hardness, wear resistance) and functional properties (thermal stability, dielectric behavior, biocompatibility) of additively manufactured ceramics, and discuss their current and potential engineering applications in the aerospace, defense, automotive, biomedical, and energy sectors. Persistent challenges, including porosity, shrinkage and cracking during sintering, achieving uniform microstructures, high process costs, and scalability issues, are analyzed, and we highlight promising future directions such as multi-material grading, integration of machine learning for process optimization, and sustainable manufacturing approaches. Despite significant progress, challenges remain in achieving fully dense structures, improving process reliability, and scaling ceramic AM for industrial applications, highlighting the need for further research in process optimization, material design, and multi-material integration.

Ceramics doi: 10.3390/ceramics9040042

Authors: Stevan Stojadinović Darwin Augusto Torres-Ceron Sebastian Amaya-Roncancio Nenad Radić

Porous, crystalline gamma-Al2O3 coatings with a thickness of (6 ± 0.5) μm and a uniform distribution of rare earth (RE) dopants are synthesized by plasma electrolytic oxidation of aluminum at a current density of 150 mA/cm2 in a boric acid and borax (BB) solution containing added RE oxide particles (Ho2O3, Tb4O7, and Pr6O11) at concentrations of 1, 2, and 4 g/L. The concentration of RE oxide particles in the BB solution determines the amount of RE elements incorporated into the coatings but does not significantly affect their surface morphology, crystal structure, or light absorption properties. The coatings exhibit high absorption in the middle/near-ultraviolet region, characteristic of Al2O3. Typical 4f-4f transitions of Ho3+, Tb3+, and Pr3+ are observed in the photoluminescence spectra. Photocatalytic evaluations using methyl orange degradation under simulated solar irradiation show that RE doping significantly enhances photocatalytic efficiency. Peak degradation efficiencies are achieved at a concentration of 4 g/L for all RE oxides. After 8 h of irradiation, maximum degradation reaches 88%, 92%, and 85% with pseudo-first-order rate constants (kapp) of about 0.274 h−1, 0.339 h−1, and 0.232 h−1 for coatings synthesized in BB with 4 g/L Ho2O3, Tb4O7, or Pr6O11, respectively. In comparison, the pristine Al2O3 coating achieves only about 50% degradation (kapp ≈ 0.087 h−1). Photoluminescence indicates that RE3+ ions serve as effective charge-carrier traps, suppressing electron–hole pair recombination. RE-doped Al2O3 coatings demonstrate exceptional structural stability and reusability over six cycles, highlighting their potential for sustainable wastewater remediation.

Ceramics doi: 10.3390/ceramics9040041

Authors: Malika Saâdaoui

Engineering ceramics are successfully used as structural or functional materials in a wide range of technical and biomedical applications [...]

Ceramics doi: 10.3390/ceramics9040040

Authors: Shuxin Liu Xinglian Song Changchun Wang Wenju Liao Zhen Wang Haomiao Yu

The traditional solid-state method was employed in this study to prepare Mn-Zn ferrite. By adjusting the sintering temperature and the MoO3 doping ratio, the evolution of its structural and magnetic properties was systematically investigated. Fe2O3, MnO, and ZnO were used as the main raw materials, with MoO3 serving as an additive. MoO3 was doped at molar ratios ranging from 0 to 1000 ppm under experimental conditions involving a sintering temperature between 1125 °C and 1165 °C and an oxygen concentration of 1.5%. The addition of an appropriate amount of MoO3 led to an increase in the Q value, which consequently resulted in a reduction in the loss. The formation of a single-phase spinel structure was confirmed by X-ray diffraction analysis. Observations of the surface morphology revealed that the grain size also increased with the increase in MoO3 content, a trend consistent with the enhanced grain growth kinetics at higher MoO3 levels. In this study, a Mn-Zn ferrite material with excellent comprehensive performance was successfully prepared under the optimal conditions of a sintering temperature of 1150 °C and a MoO3 doping concentration of 500 ppm. A Q value of 22.3 was obtained for this material at 25 °C, while a Q value of 15.7 was obtained at 100 °C. At room temperature, a Q value of 192.4 was measured at a test frequency of 500 kHz, and a Q value of 137.2 was measured at 1 MHz. At a frequency of 500 kHz, a loss of 27.1 kW/m3 was observed at 25 °C, and a loss of 53.6 kW/m3 was observed at 100 °C. At a frequency of 1 MHz, a loss of 88.2 kW/m3 was recorded at 25 °C, while a loss of 183.7 kW/m3 was recorded at 100 °C. Additionally, the lattice constant was stabilized in the range of 8.52–8.53 Å, indicating favorable structural stability.

Ceramics doi: 10.3390/ceramics9040039

Authors: Alfredo Aguilar-Elguezabal Armando Reyes-Rojas Hilda Esperanza Esparza-Ponce Daniel Lardizábal-Gutiérrez Miguel Humberto Bocanegra-Bernal

Ceramic materials are indispensable to aerospace and defence technologies, where structural and functional components are required to withstand extreme thermal, mechanical, and chemically aggressive environments. Traditionally valued for their exceptional thermal stability, oxidation resistance, and corrosion resistance, ceramics have nonetheless been constrained by their inherent brittleness, which has limited their widespread adoption in load-bearing structural applications. This review surveys the principal tough ceramic systems currently employed in aerospace and defence, including SiC, Al2O3, ZrO2, Si3N4, SiC/SiC composites, and ultra-high-temperature ceramics (UHTCs) such as ZrB2 and HfB2. In parallel, it outlines advanced processing and manufacturing routes that enable enhanced microstructural control, improved reliability, and scalability for industrial deployment. Special attention is devoted to thermal and environmental barrier coatings (TBCs and EBCs), which provide critical protection against oxidation, corrosion, and severe thermal cycling in propulsion, power-generation, and hypersonic systems. Finally, the review highlights key material selection criteria for aerospace and defence platforms and discusses emerging trends that integrate tough ceramics with next-generation manufacturing technologies, underscoring their pivotal role in enabling high-performance, durable, and resilient systems for future extreme-environment applications.

Ceramics doi: 10.3390/ceramics9040038

Authors: Daniela Gier Della Rocca Victor de Aguiar Pedott Fernanda Cristina Fraga Adriano da Silva Rosely Aparecida Peralta Enrique Rodríguez-Castellón Natália Ueda Yamaguchi Bruno Francisco Oechsler Regina de Fátima Peralta Muniz Moreira

Membrane technology is a highly efficient, cost-effective, and chemical-free process, leading to its widespread application across various fields. However, the high capital cost of traditional ceramic benchmarks remains a barrier. This study addresses this challenge by engineering a low-cost, waste-derived geopolymeric membrane functionalized with a silver molybdate (Ag2MoO4) catalytic coating for the removal of trimethoprim (TMP), a persistent emerging contaminant. Systematic filtration assays for the removal of TMP (100 mg·L−1, pH 4) revealed the role of the Ag2MoO4 layer as a performance intensifier, yielding a 26% increase in initial permeate flux and a 33% improvement in the selectivity compared to the pristine support, while maintaining robust rejection efficiency. Comprehensive characterization attributes these enhancements to synergistic effects between increased surface hydrophilicity and favorable solute–catalyst interfacial interactions. Furthermore, a fouling analysis using Hermia’s models indicated the simultaneous operation of multiple blocking mechanisms, a phenomenon linked to the non-uniform nature of the coating and subsequent formation of preferential flow paths. Overall, the incorporation of the silver molybdate coating effectively improved the membrane’s flux performance and selectivity. These findings demonstrate that integrating catalytic coatings onto waste-based geopolymer frameworks provides a scalable, circular-economy-aligned strategy for advanced wastewater treatment, balancing high-flux performance with the efficient removal of recalcitrant pharmaceuticals.

Ceramics doi: 10.3390/ceramics9040037

Authors: Chaochen Chen Fang Lei Shiqing Dang Hongyang Zhang Ying Shi Haohong Chen

To address the lack of suitable glass systems for silicon nitride (Si3N4) surface metallization, which requires high wettability and thermal stability, and robust bonding between the copper layer and the ceramic substrate, a novel Bi2O3-TeO2-B2O3-CuO glass system was developed. This study systematically investigated the influence of Bi2O3 concentration, glass properties, optimized paste composition, and brazing mechanism using phase analysis, microstructural characterization, particle size statistics, thermal analysis, and tensile testing. An optimal glass composition containing 20 mol% Bi2O3 was identified, exhibiting high thermal stability (ΔT = 224 °C) and a coefficient of thermal expansion of 9.63 × 10−6 °C−1. At a brazing temperature of 750 °C, the glass demonstrated excellent wettability with a contact angle of 27°. A conductive paste comprising 94 wt% Cu and 6 wt% glass yielded a thick film with a minimum resistivity of 6.25 μΩ·cm and a maximum tensile strength of 25.2 MPa. Mechanism analysis revealed that the superior wettability drives the liquid glass phase to form a thin intermediate layer that significantly reinforces adhesion. These findings contribute to the research and development of subsequent novel glass systems with superior performance.

Ceramics doi: 10.3390/ceramics9040036

Authors: Carlos Andres Cardenas Balaguera Andres Felipe Rubiano-Navarrete Pilar Astrid Ramos Casas Lina Paola Espitia López

The research focuses on the development of chemically bonded phosphate ceramics using potassium hydrophosphate and steel slag (EAF) as raw materials. The objective is to scale up the laboratory results to design a ceramic paste suitable for architectural monolithic products, promoting the recycling of EAF steel slag. The methodology includes field visits, grinding and sieving of raw materials, and the fabrication of specimens following ASTM standards. The laboratory results from existing studies on multiphase phosphate cements from steel slags indicate that exothermic reactions and the increase in reactants can affect process scaling. Furthermore, shaping methods such as casting and pressing are evaluated, where pressing proves to be the most suitable for this type of phosphate cement as it increases the material’s mechanical properties (compressive strength), reduces porosity, and generates a greater utilization of the EAF steel slag residue. Taking into account Colombian technical standards regarding the minimum compressive strength that a monolithic architectural object must withstand for structural and non-structural use, the results obtained in this research allow us to conclude that this material can indeed be used for architectural purposes.

Ceramics doi: 10.3390/ceramics9030035

Authors: Aime Gutiérrez Peralta Fernando Daniel Cortés Vega Susana Meraz Dávila

This work investigates the effect of high-energy mechanical milling on the activation and phase transformation of synthetic pseudoboehmite powders. The approach aims to provide a clean, solvent-free route with potential industrial relevance for alumina production. Mechanical processing proved effective in inducing the transition from pseudoboehmite to χ-Al2O3 solely through milling. The process yielded nanometric particles with low levels of contamination. The subsequent conversion to α-Al2O3 was achieved through controlled heat treatments, while phase evolution was monitored by differential scanning calorimetry (DSC). A reduction of approximately 110 °C in the α-Al2O3 formation temperature was observed after 30 h of milling. This shift was accompanied by a marked decrease in the activation energy, from 526 kJ·mol−1 for the raw powder to 347 kJ·mol−1 for the milled sample. These results demonstrate the strong mechanochemical activation of pseudoboehmite, highlighting mechanical milling as an effective and scalable route for energy-efficient processing of alumina phases.

Ceramics doi: 10.3390/ceramics9030034

Authors: Pedro Henrique Poubel Mendonça da Silveira Ary Machado de Azevedo Marcelo Henrique Prado da Silva

Hydroxyapatite (HAp) is a key bioceramic for biomedical applications, but conventional pressureless sintering (PS) requires high temperatures that can promote phase degradation. Here, we compare PS (1100 °C/180 min) and cold sintering process (CSP) (150 °C/450 MPa/30 min) for pure HAp and an HAp composite containing 4 wt.% niobium–phosphate bioglass (BG), using a 2 M H3PO4 transient liquid (10 wt.%). CSP increased relative density from 73.10% to 79.92% for HAp and from 68.43% to 83.54% for HAp/BG, representing up to a 22.1% gain compared with PS. One-way ANOVA confirmed a significant effect of processing route/composition on relative density (F(3,24) = 919.69, p < 0.05), and Tukey HSD indicated that all groups differed statistically. SEM revealed a markedly more consolidated and homogeneous microstructure for CSP, particularly for HAp/BG, consistent with enhanced dissolution–reprecipitation and pore filling. XRD showed that PS at 1100 °C led to partial HAp degradation with β-TCP formation, whereas CSP preserved the HAp phase with broader peaks, smaller crystallite size, and higher specific surface area. These results demonstrate CSP as an efficient low-temperature alternative for densifying HAp-based bioceramics, with BG addition further improving consolidation.

Ceramics doi: 10.3390/ceramics9030033

Authors: Amina Benatia Najwa Gouitaa Ina Turcan Felicia Gheorghiu Laura-Elena Ursu Liviu Leontie Liliana Mitoseriu Fatima Zahra Ahjyaje Taj-dine Lamcharfi Farid Abdi

This research aims to investigate the modifications of the structural, dielectric, and sensing properties of CaFeO3−δ ceramics produced by solid-state reaction induced by varying sintering temperatures in the range of 1000–1200 °C. A single crystallographic orthorhombic (Pcmn) structure was revealed by X-ray diffraction with Rietveld analysis, both for the powders and sintered ceramics, irrespective of the sintering temperature. The increase in the sintering temperature induces better densification and a larger grain size. Dielectric measurements reveal a pronounced enhancement of the relative permittivity, reaching 2 × 105 at 1 kHz and 330 °C for the sample sintered at 1200 °C/4 h. This composition also displays the highest electrical conductivity, 0.4 S/m at 1 MHz. Cole–Cole analysis indicates a clear deviation from ideal Debye behavior, while the relaxational features of the dielectric permittivity suggest a strong correlation between the dielectric response and Fe-related conduction mechanisms. Gas sensing tests show that the ferrite ceramics exhibit consistent ethanol response trends. The ceramic sintered at 1200 °C/4 h achieved the highest sensitivity, of 56.28%, which can be attributed to its higher density, larger ceramic grains, and reduced low-frequency conductivity. The CaFeO3−δ ceramic sintered at 1200 °C/4 h shows a combination of high permittivity, enhanced conductivity, and strong ethanol sensitivity, making it a promising material for dielectric components, capacitive devices, and gas sensing applications.

Ceramics doi: 10.3390/ceramics9030032

Authors: Benyapa Korcharoenrat Tool Sriamporn Niyom Thamrongananskul Nantawan Krajangta Awiruth Klaisiri

The aim of this research was to assess the effects of different adhesive surface treatment protocols using universal adhesives on the shear bond strength (SBS) between a Vita Enamic and resin composite, as well as to analyze the associated failure modes. Eighty Vita Enamic ceramics were prepared, thermocycled, and randomly allocated into eight experimental groups following silane coupling agent pretreatment and adhesive system: Single Bond 2 (SB), silane + SB, Scotchbond Universal Plus (SBP), silane + SBP, Beautibond Xtreme (BEX), silane + BEX, Tetric N-Bond Universal (TUB), and silane + TUB. All specimens were etched with 9% hydrofluoric acid prior to adhesive application. Resin composites were bonded to the treated surfaces and subjected to SBS analysis using a universal testing device. Failure modes were performed under a stereomicroscope. Data were statistically determined using one-way ANOVA and Tukey’s post hoc test (α = 0.05). Statistically significant differences in SBS were indicated among the groups (p < 0.05). In the result, the SB (13.96 ± 2.34 MPa) and TUB (12.39 ± 2.91 MPa) groups exhibited the lowest SBS values and exclusively adhesive failure modes. Groups treated with silane and/or silane-containing universal adhesives (Sl + SB; 18.42 ± 3.11 MPa, SBP; 19.01 ± 2.62 MPa, BEX; 19.20 ± 2.96 MPa and Sl + TUB; 18.16 ± 2.82 MPa) demonstrated significantly higher SBS. The highest SBS values were achieved in the silane + SBP (24.53 ± 2.66 MPa) and silane + BEX (25.12 ± 2.74 MPa) groups, which were statistically comparable to each other and superior to all other groups. These groups also showed increased proportions of mixed and cohesive failures, indicating improved interfacial integrity. In conclusion, the SBS between Vita Enamic and the resin composite was significantly influenced by surface pretreatment and adhesive composition. Hydrofluoric acid etching combined with silane coupling agent pretreatment and silane coupling agent-containing universal adhesives provided the highest bond strength, supporting a multimodal strategy for the reliable repair of Vita Enamic restorations.

Ceramics doi: 10.3390/ceramics9030031

Authors: Eckart Uhlmann Xinyu Zhang Anton Hoyer

In this study, the material removal behavior of abrasive brushing tools on zirconia-toughened alumina cutting edges is experimentally investigated. Three different brushing tool specifications with bonded diamond grains are tested, varying in filament diameter, filament length, and grain size. Using an industrial robot setup, structured brushing experiments are performed on the cutting edges of indexable inserts under controlled variations of key process parameters, such as brushing velocity vb, axial feed rate vfa, infeed ae, and contact angle φ. The resulting edge rounding is quantified using three-dimensional optical scanning. Key metrics, such as edge radius rβ and form factor K, are evaluated to assess the suitability of abrasive brushing processes for the preparation of ceramic cutting edges. The results showed that the edge radius ranged from rβ = 20 to 80 µm, while the form factor varied from K = 1 to 3. The brushing velocity vb and axial feed rate vfa were identified as the primary parameters influencing the rounding radius rβ, whereas the infeed ae was the dominant parameter affecting the form factor K. While cutting edge preparation of metal and carbide tools is well studied, little research exists on abrasive brushing of zirconia-toughened alumina (ZTA) cutting inserts. Because ZTA behaves differently from metals, this study systematically investigates robot-assisted abrasive brushing of ZTA, analyzing how key process parameters affect edge radius, shape, and uniformity along the cutting edge.

Ceramics doi: 10.3390/ceramics9030030

Authors: Suela Hoxha Teuta Pustina-Krasniqi Fisnik Aliaj

The aim of this in vitro study was to evaluate and compare the color stability of different CAD/CAM ceramic materials after artificial aging induced by thermocycling. Two hundred disk-shaped specimens were fabricated from five CAD/CAM materials: high-translucent zirconia (HT), ultra-high-translucent zirconia (UHT), standard translucent zirconia (ST), a polymer-infiltrated hybrid ceramic (CERASMART 270), and a lithium disilicate glass-ceramic (GC Initial LiSi Block). Color measurements were performed at baseline and after 10,000 thermocycling cycles (5–55 °C) using a VITA Easyshade® spectrophotometer. Color coordinates (CIE L*, a*, b*) and overall color differences (ΔE) were calculated. Statistical analysis was applied to determine material-dependent differences. All materials exhibited statistically significant color changes after thermocycling (p < 0.001). The color change varied by material. Lithium disilicate showed the highest ΔE values, whereas UHT, HT zirconia and CERASMART 270 showed lower color changes, yielding results within clinically acceptable limits. Color stability after thermocycling is highly material-dependent. Zirconia-based and polymer-infiltrated ceramics showed superior optical aging resistance compared to lithium disilicate ceramics, indicating their clinical suitability for long-term esthetic CAD/CAM restorations.

Ceramics doi: 10.3390/ceramics9020029

Authors: Cesar Martins Fraga Edmilson Monteiro de Souza Alexander Machado Cardoso

Spent fluid catalytic cracking catalysts (E-cat) are a challenging waste from the petroleum refining industry, enriched with heavy metals such as nickel, vanadium, and iron. This study proposes a circular valorization strategy by incorporating E-cat into a chemically bonded iron phosphate ceramic matrix, known for its excellent waste stabilization properties. Composites were synthesized at room temperature using E-cat, hematite, and phosphoric acid, with E-cat contents from 0% to 35%. Characterization by XRF, XRD, SEM, compressive strength, and water absorption tests identified an optimal formulation containing 16% E-cat, achieving a maximum compressive strength of 16.6 MPa, 35% higher than the control. This improvement can be attributed to the dual function of E-cat, acting both as a micro-aggregate that promotes matrix densification and as a pozzolanic component that enhances mechanical reinforcement. These results demonstrate that iron phosphate ceramics represent a low-energy and sustainable strategy for the immobilization of spent catalysts and the production of durable construction composites.

Ceramics doi: 10.3390/ceramics9020027

Authors: Yuying Wang Chaoyang Liu Yanping Tan Songsong Zhang Ting Zhu Deyi Zheng Xingchao Tian

To synergistically integrate piezoelectric and varistor functionalities in a single material, PNN-PZT piezoelectric powder (abbreviated as P) and ZnO-based varistor powder (abbreviated as Z) were utilized to fabricate PZT-ZnO composite ceramics (denoted as PZm) via conventional solid-state sintering. The P/Z molar ratio was regulated to 1/0.9, 1/1.05, 1/1.2, 1/1.35, and 1/1.5 to systematically study its influence on the phase composition, microstructure, and electrical properties of the composites. XRD, SEM, EDS characterization, and electrical performance tests were carried out. Results indicate that all PZm samples exhibit the biphasic coexistence of perovskite (piezoelectric phase) and wurtzite (varistor phase) without impurity phases, consisting of large perovskite grains with distinct edges and small wurtzite grains with smooth surfaces. The PZ3 sample (P/Z = 1/1.2) achieves optimal comprehensive properties: d33 = 161 pC/N, kp = 0.25, Ɛr = 2527, tan δ = 3.83%, E1mA = 1396 V/mm, IL = 8.2 mA, α = 22.06. This work confirms the synergistic optimization of piezoelectric and varistor properties in PZT-ZnO composites, providing a reliable experimental basis for the formulation design and performance regulation of multifunctional ceramics.

Ceramics doi: 10.3390/ceramics9020028

Authors: Apichai Maneenacarith Tool Sriamporn Niyom Thamrongananskul Nantawan Krajangta Thanasak Rakmanee Awiruth Klaisiri

This in vitro study investigated whether piranha solution treatment, applied alone or following sandblasting, enhances the shear bond strength of resin cement to zirconia. Fifty zirconia specimens were assigned to five groups: no treatment, sandblasting (SB), piranha solution (Pi), sandblasting followed by piranha solution treatment (SB + Pi), and double piranha treatment (Pi + Pi). Shear bond strength was measured after 24 h water storage, and failure modes were recorded. The SB + Pi group produced significantly higher bond strength than all other groups. Single treatments (SB, Pi, and Pi + Pi) yielded statistically comparable values, all exceeding the untreated control. Notably, double piranha application offered no benefit over a single application. These findings are preliminary and limited to short-term in vitro conditions; the piranha protocol is not feasible for direct clinical use due to safety constraints, and no aging or surface characterization data were obtained.

Ceramics doi: 10.3390/ceramics9020026

Authors: Diana Vitiello Ilona Kieliba Sawao Honda Benoit Nait-Ali Nicolas Tessier-Doyen Hans Ulrich Marschall David S. Smith

Alumina-spinel refractory bricks, composed of 82 wt.% alumina and 18 wt.% MgAl2O4 spinel phases, are used in steel ladles due to their ability to resist chemical attack and thermal shock. Thermal shock resistance is determined, in part, by the thermal conductivity of the material. Thermal conductivity measurements for alumina-spinel refractory, three model alumina ceramics, and single crystal sapphire were made with the laser-flash technique from 20 °C to 1000 °C. At room temperature, these gave 6.5 W m−1 K−1 for the refractory, 5.8 to 22 W m−1 K−1 for the alumina ceramics, and 36 W m−1 K−1 for sapphire, despite all materials containing >81 vol.% of alumina. The differences are explained by the roles of porosity, grain boundary thermal resistance, and the spinel phase (refractory). In order to estimate the thermal conductivity of alumina grains in each material, these microstructural effects are modelled with Landauer’s relation for porosity and thermal resistors in series for grains combined with grain boundaries. For two alumina ceramics, the grains yielded similar behaviour to the single crystal. By taking the spinel phase into account with a two-phase mixture relation, the alumina grains in the refractory were estimated with a value of 31 ± 2 W m−1 K−1, close to sapphire.

Ceramics doi: 10.3390/ceramics9020025

Authors: Shenglin Li Baozhen Chen Yuanpeng Sun Yan Wang Keyao Xie Xuepeng Chen

In response to the high stiffness and hardness levels of alumina ceramic materials, the traditional SHPB (split Hopkinson pressure bar) experimental setup has been modified. This study analyzes the propagation patterns of stress waves in the SHPB system after adding cushion blocks. Experiments demonstrated that the modified SHPB apparatus can effectively perform dynamic mechanical property tests on alumina ceramics. The JH-2 constitutive damage model parameters for alumina ceramics were determined based on theoretical analysis and static/dynamic experimental data. An LS-DYNA numerical model for the impact compression simulation of alumina ceramics was established to investigate the effects of stress waves with three wavelengths (300 mm, 400 mm, and 600 mm) at the same impact velocity, along with the dynamic fragmentation process. The results indicate that alumina ceramics exhibit strain rate hardening effects in compressive strength, failure strain, and elastic modulus under high strain rates; compressive strength and failure strain show positive correlations with stress wave wavelength under high strain rates; and microcracks initially nucleate preferentially along grain boundaries on the end surfaces, forming annular damage zones symmetrically about the central axis. This study presents a modified SHPB setup that improves test capability for high-hardness ceramics, rather than overturning classical methodologies. The absence of a direct comparison with unmodified setups stems from the known limitations of conventional systems in handling small-diameter alumina specimens without bar damage—a challenge addressed proactively in this work through impedance-matched cushion blocks and refined data processing.

Ceramics doi: 10.3390/ceramics9020024

Authors: Abigail Parra Parra Rene Guardian Tapia Ximena Cecilia Ramírez López Marina Vlasova Pedro Antonio Márquez Aguilar

This work analyzes phase transformations in quaternary mixtures (clay–glass–hematite–waste activated sludge (WAS)), processed at 800–1000 °C under conditions of oxygen deficiency. The results of the study showed that, depending on the temperature treatment of mixtures of different compositions, the processes of carbon formation from WAS, carbon participation in reductive processes, and phase transformations in silicate subsystems occur simultaneously. After Ttr = 800 °C the main phases are fayalite and quartz, additional phases are wollastonite and feldspars. After Ttr = 900 °C the main phases are fayalite, quartz, wollastonite, and the additional phases are feldspars. After Ttr = 1000 °C the main phases are wollastonite, iron, quartz, additional phases are hematite, fayalite.

Ceramics doi: 10.3390/ceramics9020023

Authors: Yang Wang Naoyuki Hashimoto Hiroshi Oka Shigehito Isobe

High-purity Zr3AlC2 samples (>92 wt%) were synthesized and irradiated at room temperature using 100 keV He+ ions at fluences of 2 × 1016 and 1 × 1017 ions/cm2. As a Zr-based MAX phase, Zr3AlC2 is a promising candidate for accident-tolerant fuel cladding due to its compatibility with Zr alloys and the low neutron absorption cross-section of Zr. Our results show that irradiation induces a decrease in the a-lattice parameter and an increase in the c-lattice parameter, along with the formation of anti-site defects and decomposition into ZrC. Cracks preferentially appear along (1000) planes. These findings suggest that Zr3AlC2 has limited structural stability under low-temperature helium irradiation.

Ceramics doi: 10.3390/ceramics9020022

Authors: Xuan Lv Zhen Wang Maolin Zhang Min Wang Guoping Pan

Longquan celadon represents the pinnacle of Chinese celadon, and there are many kilns in southern China that imitate Longquan celadon. During the Ming Dynasty, Jianyang Bowl Kiln was the representative kiln in Fujian Province for imitating Longquan celadon, while Jingdezhen Kiln was the representative kiln in Jiangxi Province for imitating Longquan celadon. The quality of both is close to that of Longquan celadon, making it difficult to distinguish by ordinary visual observation. This study focuses on Jianyang Bowl Kiln and Jingdezhen Kiln imitating Longquan celadon, comprehensively employing methods such as EDXRF, LA-ICP-MS, and chromaticity analysis to systematically investigate the similarities and differences in the composition of their body and glaze. The results indicate that distinct differences exist in the composition of trace and rare earth elements between the imitations of Longquan celadon produced by Jianyang Bowl Kiln and Jingdezhen Kiln, and authentic celadons from Longquan Kiln, which can serve as important criteria for distinguishing kilns. This provides systematic scientific data support for identifying the technological origins and production locations of Ming Dynasty imitations of Longquan celadon.

Ceramics doi: 10.3390/ceramics9020021

Authors: Chung-Yung Lin Yu-Chang Liu Bang-Lun Jhou

The selective removal of radioactive cesium-137 and strontium-90 from high-salinity radioactive wastewater remains a critical challenge, as competing ions reduce adsorption efficiency and selectivity. In this study, high-performance granulated adsorbents were developed based on alkali-activated geopolymer matrices to enhance sorption performance. The adsorbents were synthesized by inorganic polymerization, and mechanically robust granules with controlled porosity and surface chemistry were obtained. Batch sorption experiments conducted in simulated seawater demonstrated greater than 99% removal efficiencies for cesium and strontium. Isotherm modeling confirmed high maximum sorption capacities (up to 0.41 meq/g for Cs+ and 5.07 meq/g for Sr2+). Continuous fixed-bed column tests demonstrated sustained removal efficiencies for the optimized adsorbents. Structural analyses, including scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, and X-ray diffraction, confirmed uniform elemental distribution and crystalline phases consistent with selective sorption mechanisms. Assessment of mechanical strength revealed sufficient compressive strengths to ensure operational durability under hydraulic stress. These findings demonstrate that the synthesized geopolymer-based granules are a potentially effective and versatile solution for the comprehensive treatment of radioactive wastewater.

Ceramics doi: 10.3390/ceramics9020020

Authors: Yuying Song Wenfeng Yue Fu Huang Yuqun Deng Yongjiang Zhang Junyu Ming Fayaz Hussain Adil Alshoaibi Gulmurza Abdurakhmanov Junjun Wang Dawei Wang

Dielectric capacitors, characterized by ultra-fast charge/discharge speeds and high power densities, are widely used in modern electronic power systems. However, their low energy density and poor thermal stability limit applications. In this study, SrBi3.25La0.75Ti4O15 (SBLT) ferroelectric thin films were prepared by the sol–gel method. We systematically investigated the effect of annealing temperature on microstructural evolution, electrical properties, and energy storage performance. The SBLT film annealed at 700 °C exhibited optimal performance, achieving a balanced enhancement in polarization and breakdown strength, with an energy storage density of 48.66 J cm−3 and an efficiency of 78%. The material also demonstrated excellent thermal stability (30–175 °C) and frequency stability (0.1–100 kHz). These findings not only validate the potential of SBLT as a next-generation energy storage dielectric but also provide a practical solution for applications in semiconductor technology.

Ceramics doi: 10.3390/ceramics9020019

Authors: Oscar Graos-Alva Aldo Castillo-Chung Juan Carlos Rodríguez-Soto Carlos Vásquez-Boyer Alexander Vega-Anticona

Valorizing construction and demolition waste (CDW) via alkaline activation enables low-carbon binders. This study assesses binary geopolymers formulated with recycled brick powder (PLR) and recycled concrete powder (PCR) in seven precursor ratios (0–100% PCR), activated with a ternary NaOH/Na2SiO3/KOH solution (silicate modulus Ms ≈ 3.2) at L/B = 0.15, and cured for 7, 14, and 28 days. Compressive strength (fc), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) were used to link microstructure–phases–properties. A local maximum in fc at ~30% PCR (16.2 MPa at 28 d) was observed versus 0% PCR (14.2 MPa) and ≥50% PCR (13.8 → 10.1 MPa at 28 d). XRD indicated a reduction in inherited crystalline phases and an increased amorphous fraction at ~30% PCR; FTIR (normalized peak position and FWHM of the T–O–Si band, not absolute intensity) suggested higher network extension; SEM-EDS (local/semiquantitative) showed a moderate rise in Ca that supports C-A-S-H domains bridging the N-A-S-H network. At a high PCR, excess Ca simplified mineralogy (quartz/portlandite dominance), promoted competitive routes (C-S-H/carbonation), reintroduced microdefects, and reduced fc. A theoretical oxide balance per mix identified a compositional window where Ca/(Si + Al) ≈ 0.35–0.45 coincides with the mechanical optimum and with XRD/FTIR tracers. Overall, a ~30% PCR window maximizes co-reticulation of N-A-S-H/C-A-S-H and densification without compromising aluminosilicate continuity, providing transferrable design and process-control criteria for CDW-based geopolymer binders.

Ceramics doi: 10.3390/ceramics9020018

Authors: Jia Li Huitao Guo Yuxin Chen Guifen Fan Fangfang Zeng

As the operational demands on piezoelectric devices grow increasingly stringent, there is an urgent need for materials capable of delivering stable performance at elevated temperatures. BiFeO3 (BF), a lead-free piezoelectric oxide with high-temperature resilience, is characterized by its notably high Curie temperature (Tc ∼ 835 °C), rendering it a promising candidate for high-temperature applications. However, its piezoelectric coefficients remain inadequate to satisfy practical requirements. The 0.7BiFeO3-0.3Ba(1-x) SrxTiO3 system (abbreviated as BF-BSxT) was designed to elucidate the roles of chemical disorder and local structural heterogeneities in the enhancement of functional properties through fine-tuning of the Sr content. The phase structure of the samples was carefully examined by X-ray diffraction. Rietveld refinement of the XRD data revealed that all BF-BSxT ceramics consist of coexisting R and PC phases. Optimized compositional disorder and local heterogeneities led to a moderate enhancement in the piezoelectric coefficient d33 value of 160 pC/N, a high Tc of 495 °C, and a remanent polarization Pr ≈ 22.1 μC/cm2 -were achieved in the BF-BSxT system at x = 0.06. These results indicate that BF-BSxT ceramics hold good potential for use in high-temperature piezoelectric devices.

Ceramics doi: 10.3390/ceramics9020017

Authors: Caterina Sgarlata Luciana Cupertino Lorenzo Serafini Cristina Siligardi

The ceramics industry has long embraced the principles of the circular economy, with a strong focus on the reuse and recovery of raw materials essential to the production cycle. This approach reduces costs by reintroducing secondary raw materials—such as production scraps and recycled materials—into the manufacturing process after appropriate recovery treatments. This study aims to contribute to the transition of the ceramic industry toward a circular economy by incorporating industrial by-products into monoporosa ceramic bodies, thereby transforming waste materials into valuable resources. Monoporosa is a porous, single-fired ceramic wall tile characterized by a high carbonate content and low bulk density. However, the role of secondary raw materials in monoporosa formulations, as well as their influence on processing behavior (e.g., during sintering) and on key technological properties, is not yet fully understood. This work investigates a standard monoporosa formulation based on conventional raw materials (sand, calcite, feldspars, and clays) and compares it with new formulations in which industrial waste materials from local and national sources—originating from other industrial processes—are used as partial or total substitutes for some of the traditional raw materials, particularly sand and calcite. The industrial by-products examined include biomass bottom ash, foundry sand, and marble cutting and processing sludge. All materials were characterized using chemical–mineralogical, thermal, and morphological analyses and were incorporated into the ceramic bodies at different substitution levels (10%, 50%, and 100%) to replace natural raw materials. Their behavior within the mixtures was evaluated to determine ceramic suitability and acceptable replacement ratios. Furthermore, the effects of these additions on water absorption, thermal expansion coefficient, and microstructural characteristics were assessed. Based on the positive results obtained, this study demonstrates the feasibility of using, in particular, two secondary raw materials—foundry sand and marble sludge—in monoporosa body formulations, allowing for the complete replacement of the original raw materials and thereby contributing to the development of more sustainable ceramic compositions.

Ceramics doi: 10.3390/ceramics9020016

Authors: Edwin Francis Cárdenas Correa Edgar Absalón Torres Barahona Juan Bautista Carda Castelló

In additive manufacturing technologies, the use of pastes and inks based on materials such as clay to create three-dimensional objects layer by layer has opened new possibilities in fields such as engineering and biomedicine. This review article aims to provide a comprehensive understanding of 3D printing of ceramic pastes through Direct Ink Writing (DIW), also referred to as Robocasting. DIW offers specific advantages for ceramic 3D printing, including the ability to extrude highly loaded pastes with customized rheological properties to accommodate a broad spectrum of ceramic compositions, varying from conventional clays to advanced ceramics. It is characterized by filament deposition control, which facilitates the fabrication of complex, porous, or customized architectures while simultaneously minimizing material waste. Through a bibliometric analysis of the literature published between 2020 and 2024, the most relevant studies regarding printing system architectures, ceramic paste formulations, and adjustment of parameters to obtain high-quality parts were identified. This work presents relevant and accurate explanations of the DIW technology, supporting researchers and industry professionals seeking to initiate or improve ceramic 3D printing processes for a wide range of applications.

Ceramics doi: 10.3390/ceramics9020015

Authors: Jie Feng Xishun Zheng Deyi Zheng

Bismuth layer-structured ferroelectrics (BLSFs) are core candidates for high-temperature piezoelectric applications owing to their excellent thermal stability and fatigue resistance, yet traditional Bi4Ti3O12 (BiT)-based ceramics suffer from limited piezoelectric performance. To address this, MBi4Ti4O15-Bi4Ti3O12 (M=Ba, Sr, Ca) symbiotic structure bismuth-layered piezoelectric ceramics were fabricated via the conventional solid-state reaction method. Their crystal structure, microstructure, and electrical properties were systematically characterized using a X-ray diffractometer, scanning electron microscope, high-temperature dielectric spectrometer, and quasi-static d33 meter to explore the effects of different A-site divalent elements. Results show that all samples form a pure-phase symbiotic structure with the P21am space group, without secondary phases. The lattice constant decreases with increasing A-site ionic radius, while symbiosis-induced lattice mismatch and long-range disorder refine grains, reduce aspect ratio, lower conductivity, enhance spontaneous polarization, and improve piezoelectric properties. The ceramics exhibit d33 of 10 to 15 pC/N and TC of 502 to 685 °C, with SrBi4Ti4O15-Bi4Ti3O12 showing optimal comprehensive performance (d33 ≈ 15 pC/N, TC = 593 °C, tanδ = 0.6% at 1 kHz/475–575 °C, and a low AC conductivity of 5.3 × 10−5~4.8 × 10−4 S/m). This study improves bismuth-layered ceramics’ performance via A-site regulation and symbiotic structure design, offering theoretical and technical support for high-performance lead-free high-temperature piezoelectric ceramics.

Ceramics doi: 10.3390/ceramics9020014

Authors: Seung Joon Yoo Ji Su Kim Jung Hoon Choi Jin Ho Kim Kyu Sung Han Ung Soo Kim

Alumina ceramics used in semiconductor plasma environments require high densification, microstructural homogeneity, and stable performance under increasingly aggressive processing conditions. However, systematic studies linking slurry processing parameters to the plasma resistance of alumina ceramics remain limited. In this study, the effects of slurry preparation parameters—specifically milling and aging—and sintering atmosphere on the densification, mechanical strength, and plasma etching resistance of slip-cast alumina ceramics were systematically investigated. Optimal dispersion stability was achieved under 12 h milling and 12–24 h aging conditions, resulting in homogenized green body packing and a high relative sintered density exceeding 99%. Mechanical strength and plasma resistance were strongly influenced by slurry aging and sintering atmosphere. Specimens aged for 48 h and sintered under a low oxygen partial pressure (N2 at 1.0 L/min) exhibited the highest flexural strength and significantly improved resistance to SF6/Ar plasma etching, with reduced etch depth and suppressed surface roughening. These results demonstrate that coordinated slurry processing and sintering atmosphere control is an effective strategy for designing high-reliability, plasma-resistant alumina ceramics for high-demand semiconductor manufacturing environments.

Ceramics doi: 10.3390/ceramics9020013

Authors: Saúl Alberto Guerrero Rivero Leticia da Silva Gondim Joana B. Torres André Teixeira Nireide Pereira Tavares Jaylson Monteiro Javier Iñañez

Archaeological research on Santiago Island (Cape Verde) offers a strategic framework for investigating ceramic material culture shaped by Iberian and African interactions during the early modern period. This study presents first-stage results from a non-destructive archaeometric analysis of pottery fragments recovered from early colonial sites and curated at the Museu de Arqueologia in Praia. Using portable X-ray fluorescence spectroscopy (pXRF), low-fired, handmade vessels associated with African technological traditions were analysed to determine their elemental composition and potential provenance. The work also focused on sugar moulds, containers used in the refining of this product, one of the most important in Atlantic colonisation. The resulting geochemical data is compared with established reference groups from the Iberian Peninsula, Atlantic Africa, and Macaronesia. Elemental variability indicates the use of diverse clay sources and production techniques, reflecting hybrid technological practices shaped by cultural interaction and provisioning constraints. These results contribute to ongoing research within the CERIBAM (Iberian Atlantic Expansion in North Africa and Macaronesia) and Palarq-funded projects, which aim to reconstruct early colonial ceramic networks and sociotechnical dynamics. By integrating archaeometric data with archaeological and historical perspectives, this study aims to demonstrate the utility of non-invasive analytical protocols for understanding ceramic technology, intercultural exchange, and Atlantic material connectivity in early Creole formations while preserving the integrity of the collections.

Ceramics doi: 10.3390/ceramics9020011

Authors: Arianna Bertero Bartolomeo Coppola Laura Montanaro Matteo Bergoglio Paola Palmero Jean-Marc Tulliani

Digital Light Processing (DLP), which operates through a layer-by-layer deposition, has proven to be a promising technique for obtaining complex and customized architectures. However, there are still numerous unresolved challenges in ceramics additive manufacturing, among which is delamination due to suboptimal adhesion between the layers, which threatens the structural integrity and properties of samples. According to recent findings, excess surface hydroxyl groups were identified as being responsible for this defect; a suitable calcination pre-treatment of the ceramic powder could be effective in significantly mitigating delamination flaws in mullite DLP printed bodies. Therefore, in addition to optimizing the printable slurry formulation and printing parameters (mainly in terms of curing energy and layer resolution), this work aimed at investigating the influence of the calcination of a commercial mullite powder (added with magnesium nitrate hexahydrate, as a precursor of the sintering aid MgO) as a simple and effective treatment to additively shape ceramic bodies with limited flaws and enhanced density. The surface characteristics evolution of the mullite powder was investigated, specifically comparing samples after magnesium nitrate hexahydrate addition and ball-milling in water (labeled as BM), and after an additional calcination (BMC). In particular, the effect of the superficial -OH groups detected by FTIR analysis in the BM powder, but not in the BMC sample, was studied and correlated to the properties of the respective ceramic slurry in terms of rheological behavior and curing depth. The hydrophilicity of BM powders, due to superficial hydroxyls groups, affects ceramic powder dispersion and wettability by the resin, causing a weak interface. At the same time, it promotes photopolymerization of the light-sensitive resin, thus inducing the as-printed matrix embrittlement. Anyhow, its photopolymerization degree, equal to 67% and 55% for BM and BMC, respectively, was enough to guarantee the printability of both slurries. However, the use of BMC significantly reduced flaw occurrence in the as-printed bodies and the final density of the samples sintered at 1450 °C (without an isothermal step) was increased (approx. 60% and 50% of the theoretical value for BMC and BM, respectively). Thus, the target porosity of the ceramic bodies was guaranteed, and their structural integrity achieved without any increase in sintering temperature but with a simple powder treatment.

Ceramics doi: 10.3390/ceramics9020012

Authors: Hadjer Youcef Mohamed Toufik Soltani Dominique de Ligny

Boro-antimonite glasses doped with Eu3+ and having the general composition (90-x) Sb2O3–xB2O3–10Li2O-0.5Eu2O3 (x = 0 to 60 in 10 mol. % increment) were prepared using the melt quenching method. The influence of B2O3/Sb2O3 substitution on the spectroscopy and photoluminescence of Eu3+ ions was analyzed by studying the measured and calculated properties of these glasses. The relative value of a given property was shown to increase or decrease by up to 26% with the addition of up to 60 mol. % B2O3, while the number of Eu3+ ions per unit volume increased by approximately 32%. Strong emissions were obtained in association with the transitions of Eu3+ (5D0→7Fj, j = 1–4). A weak, broad emission centered at 450 nm was also detected. This emission is clearly linked to the glass composition. It originates from a potential presence of Eu2+ ions. This enhances 5D0 level emission via charge transfer. The radiative and experimental lifetimes of the 5D0 level increase linearly with B2O3 content. This results in high quantum efficiency (η) ranging from 74 to nearly 84%. Tunable chromaticity, as defined by the CIE 1931 standard, was achieved, resulting in a warm orange-red color with high brightness. These new glasses have a variety of potential laser-related applications.

Ceramics doi: 10.3390/ceramics9010010

Authors: Beata Śmielak Leszek Klimek Marco Ferrari Kamil Krześniak

How does zirconia processing affect the degree of tetragonal to monoclinic phase transformation (t ⟶ m) and the development and wettability of the surface? One hundred and twenty-four samples made of sintered zirconium were divided into four groups based on the following treatments: grinding, polishing, sandblasting with Al2O3, or sandblasting with SiC. After surface treatment, the samples were subjected to the following tests: X-ray diffraction, microscopic examination, surface roughness measurements, and surface wettability. The highest values are achieved after the grinding process (Ra = 0.63; Rz = 9.29; Rq = 1.28), and the lowest values are found after polishing (Ra = 0.11; Rz = 0.71; Rq = 0.36). All samples, apart from those sandblasted with Al2O3 (Θ = 121.59°), showed wettability with the polar liquid. The best wettability was noted for sandblasted SiC samples (Θ = 41.22°) and the lowest was noted for polished samples (Θ = 80.61°). All samples showed wettability with an apolar liquid (Θ < 90°). A significant transformation (t ⟶ m) was noted in all tested samples: about 14% for ground, 17% for polished, 13.8% for Al2O3 sandblasting, and 13.1% for SiC sandblasting samples. The type of processing method has a significant impact on the selected parameters of roughness, surface wettability, and phase transformations.

Ceramics doi: 10.3390/ceramics9010009

Authors: Lijuan He Yuhang Huang Jianhua Zhou Yi Wang Jingwei Yang Xuan Liu Shuping Wang Zhigang Zhang

This study systematically examines the fluidity, setting time, mechanical properties, and microstructural evolution of metakaolin-based geopolymer grouting materials with a relatively high water-to-solid (W/S) ratio window. A four-factor, three-level orthogonal experimental design was employed to identify the dominant factors and main effect trends of W/S ratio, alkali dosage, water glass modulus (Ms, molar ratio of SiO2 to Na2O in alkali solution), and steel slag content on the material’s performance. The results indicated that the W/S ratio predominantly governed fluidity, while the alkali content was the primary controlling factor for setting time and early-age strength. An intermediate range of water glass modulus with a value of 1.6 provided balanced performance. The incorporation of steel slag with a range of 10–20% showed an age-dependent contribution: it not only tended to improve the rheology of the paste but also the later-age strength. XRD, FTIR, and SEM/EDS results suggested that the hardened binders were dominated by amorphous products, where alumimosilicate gel (N-A-S-H) and Ca-containing gel (C-S-H/C-A-S-H) may coexist depending on calcium availability and activator chemistry. The proposed parameter ranges are valid within the studied design space and provide guidance for the mix design of high-W/S geopolymer grout.

Ceramics doi: 10.3390/ceramics9010008

Authors: Kyung Hoon Sun Cheol Hee Choi Chul Ho Jang

Canal wall down mastoidectomy (CWD) effectively eradicates cholesteatoma and chronic otitis media but frequently results in a problematic open mastoid cavity. Mastoid obliteration aims to reduce cavity-related morbidity. Bioceramic materials, including hydroxyapatite (HA), tricalcium phosphate (TCP), and bioactive glass (BAG), have been increasingly adopted because of their osteoconductive, biocompatible, and antimicrobial properties. This systematic review evaluates the clinical outcomes and complications of bioceramic mastoid obliteration following CWD. A systematic literature search of PubMed, Scopus, and Web of Science was conducted for studies published between 2005 and 2025, following PRISMA guidelines. Clinical studies reporting outcomes of bioceramic mastoid obliteration after CWD were included. Thirteen clinical studies were included. HA-, TCP-, and BAG-based materials demonstrated high obliteration success rates (>90% in most series). BAG S53P4 was consistently associated with low infection rates and favorable epithelialization, whereas earlier HA cement formulations were occasionally associated with revision-requiring complications. Bioceramic scaffolds represent safe and effective materials for mastoid obliteration after CWD. BAG offers additional antibacterial advantages, while HA provides predictable volume stability. Further prospective and comparative studies are required to establish material superiority and long-term outcomes.

Ceramics doi: 10.3390/ceramics9010007

Authors: Habib Rostaghi Chalaki Ebenezer Seesi Mohammad El Loubani Dongkyu Lee

Sluggish oxygen reduction reaction (ORR) remains a critical barrier to advancing intermediate-temperature electrochemical energy devices. Here, we demonstrate that strain engineering in two platforms, epitaxial thin films and freestanding membranes, systematically tunes ORR kinetics in Ruddlesden-Popper LaSrCoO4. In epitaxial films, film thickness is varied to control in-plane tensile strain, whereas in freestanding membranes strain relaxation during the release step using water-soluble sacrificial layers produces flat or wrinkled architectures. Electrochemical impedance spectroscopy analysis reveals more than an order of magnitude increase in the oxygen surface exchange coefficient for tensile-strained films relative to relaxed films, together with a larger oxygen vacancy concentration. Wrinkled freestanding membranes provide a further increase in oxygen surface exchange kinetics and a lower activation energy, which are attributed to increased active surface area and local strain variation. These results identify epitaxial tensile strain and controlled wrinkling as practical design parameters for optimizing ORR activity in Ruddlesden-Popper oxides.

Ceramics doi: 10.3390/ceramics9010006

Authors: Josef Škvarka Iva Janáková František Pticen Radmila Kučerová

This study focuses on preparing mullite grogs derived from selected waste materials and kaolin treated with advanced technologies to achieve high thermal resistance and low thermal expansion. The investigated waste materials include dust removal RON, slurry DE, feldspar dust removal from Halamky, and waste generated during the feldspar grinding at the Halamky I deposit. These materials (Red kaolin from Vidnava, Slurry DE, Dust-off RON, Feldspar dust-off Halamky) were processed into grogs and subsequently applied for the production of high-mullite ceramics. The influence of cristobalite admixture was also assessed. The chemical composition was determined by X-ray fluorescence (XRF), while the phase composition was analysed by X-ray diffraction (XRD). Amorphous mullite grogs with mullite contents greater than 40% were successfully prepared. Despite the relatively high iron content, the resulting products exhibited the desired white colour after firing and demonstrated properties that make them promising candidates for advanced refractory applications. The study highlights the potential to valorise industrial waste materials for high-value ceramic applications.

Ceramics doi: 10.3390/ceramics9010005

Authors: Xiaoran Li Lu Ren Changxin Li Lili Zhang Jincheng Ji Mao Peng Pengyu Xu

The development of lithium-ion batteries necessitates cathode materials that possess excellent mechanical and thermal properties in addition to electrochemical performance. As a prominent functional ceramic, the properties of spinel LiMn2O4 are governed by its atomic-level structure. This study systematically investigates the impact of Ni doping concentration on the mechanical and thermal properties of spinel LiNixMn2−xO4 via first-principles calculations combined with the bond valence model. The results suggest that when x = 0.25, the LiNixMn2−xO4 shows excellent mechanical properties, including a high bulk modulus and hardness, due to the favorable ratio of bond valence to bonds length in octahedra. Furthermore, this optimized composition shows a lower thermal expansion coefficient. Additionally, Ni doping concentration has a very minimal influence on the maximum tolerable temperature of the cathode material during rapid heating. Therefore, from the perspective of mechanical and thermal properties, this composition could be beneficial for improving the cycling life of the battery, since comparatively inferior mechanical properties and a higher thermal expansion coefficient make it prone to microcrack formation during charge–discharge cycles.

Ceramics doi: 10.3390/ceramics9010004

Authors: Almiro Mendes Costa Neto Caterine Yesenia Carrasco Montesdeoca Bruno Pereira da Silva Neto Amanda Miranda Franco Antonio Linkoln Alves Borges Leal Humberto Medeiros Barreto Anderson Oliveira Lobo Fernanda Roberta Marciano

This manuscript describes the development of a nano-sized synthetic smectic clay hydrogel (LAP) that enables controlled oxygen delivery, making it a promising candidate for treating skin wound infections and promoting healing. LAP is an ingredient in various dermatological products, including powders, creams and emulsions. We investigated the antibacterial effect of the LAP hydrogel by incorporating calcium peroxide (CPO), an oxygen-releasing agent, and measuring the size of the inhibitory halo. We found that CPO hydrogels in LAP showed a significant increase in oxygen release during the first five hours, especially at low CPO concentrations. For example, the hydrogel with 5% CPO showed a controlled release profile with a final percentage oxygen release of 2.47 ± 0.01% after 5 h. In contrast, the hydrogels with 10% and 20% CPO achieved lower final oxygen release values, 0.67 ± 0.01% and 0.75 ± 0.01%, respectively, suggesting that the encapsulation efficiency of LAP is higher at higher concentrations. LAP also proved to be an effective oxygen barrier and showed inherent antimicrobial activity. The research confirmed the antibacterial properties of the hydrogel, with inhibition sites observed against both E. coli and S. aureus. These results emphasize the potential of this hydrogel to serve as an effective tool for wound treatment by providing sustained oxygenation and fighting microbial infections.

Ceramics doi: 10.3390/ceramics9010003

Authors: Ahmed H. Albaqawi Mohamed F. Metwally Sami A. Almohefer Walid A. Abdelhady Moazzy I. Almansour Khaled M. Haggag Hend M. El Sayed Ferdous Bukhary Ahmed A. Madfa

This in vitro investigation evaluated the marginal fit of three pressable glass-ceramic onlay materials: a conventional monolithic lithium disilicate (IPS e.max Press, EM, ivoclar vivadent AG, Schaan, Liechtenstein) and two zirconia-reinforced glass-ceramics (Vita Ambria, VA, VITA Zahnfabrik, Bad Säckingen, Germany; Celtra Press, CP, Sirona Dentsply, Milford, CT, USA). A typodont maxillary first premolar was prepared for an intensive onlay design by a single operator using a milling surveyor. The master die was duplicated with silicone impressions to create 72 identical epoxy resin dies. Seventy-two onlays (n = 24 per material) were fabricated and adhesively cemented to their respective dies. Vertical marginal gaps were recorded under a stereo-electron microscope before and after thermomechanical loading (TML) in a chewing simulator. Data were analyzed with one-way ANOVA and Tukey’s post hoc tests for intergroup comparisons and paired t-tests for pre- versus post-TML values. All groups showed a significant increase in marginal gap following TML. VA exhibited mean gaps of 46.41 µm before and 57.28 µm after loading (p = 0.001). EM demonstrated 41.16 µm before and 46.63 µm after TML (p = 0.002). CP showed 45.70 µm before and 55.99 µm after TML (p = 0.003). Among the three materials, EM maintained the most accurate marginal adaptation both before and after simulated chewing. Despite the increases, all post-loading values remained within the clinically acceptable threshold for marginal discrepancy. These findings indicated that thermomechanical fatigue adversely affected the marginal integrity of pressable glass-ceramic onlays, including zirconia-reinforced formulations. Nevertheless, zirconia-reinforced ceramics (VA and CP) achieved marginal gaps comparable to conventional lithium disilicate and remained within acceptable clinical limits. IPS e.max Press provided the best overall fit, suggesting it may offer superior long-term marginal stability for onlay restorations.

Ceramics doi: 10.3390/ceramics9010002

Authors: Ekaterina Kuznetsova Anton Smirnov Nestor Washington Solís Pinargote Roman Khmyrov Daniil Strunevich Natella Krikheli Oleg O. Yanushevich Pavel Peretyagin Andrey V. Gusarov

Highly filled (78 wt.%) alumina filaments with various (0.05, 0.10, 0.25 vol.%) graphene oxide concentration for Fused Filament Fabrication (FFF) were obtained. In order to evaluate the effect of graphene oxide on density, microstructure, and hardness, the fabricated materials were sintered in an argon atmosphere at 1500 °C and 1550 °C. A sample that was sintered under the same conditions in air was used as a control. Raman spectroscopy confirmed the reduction in graphene oxide and the absence of carbon in samples sintered in argon and air, respectively. In addition, in the samples with graphene oxide, the alumina grain size was lower than in air-sintered samples. The composite with the lowest amount (0.05 vol.%) of graphene oxide showed the highest value (1670.73 ± 136.9 HV) hardness.

Ceramics doi: 10.3390/ceramics9010001

Authors: Astrid Holzheid Stefanie Hildebrandt Eleonora Kulik Bernhard Durschang Catherine A. Macris David W. Wallington Klaus-Dieter Schicke

Three processes for the production of ceramics close to stoichiometric MgAl2O4 are benchmarked against each other. The traditional ceramic route is based on mostly crystalline starting powder, which is converted into ceramic via shaping and heat treatment (IKTS). The other two processes are based on glasses. Partial or complete crystallization without pressure (ISC) or complete crystallization with pressure (CAU) leads to (glass) ceramics. Spinel powder is mixed with various dopants (BaO, TiO2, CaO and SrO), with the aim to reduce the grain size (IKTS). The doping results in a second, partly interfering phase, and the transmission decreases strongly due to absorption with increasing content of the added oxide. For the glass route without pressure (ISC), it is shown that a network-forming oxide (B2O3, TiO2) is needed to produce the glasses. Compared to the starting glasses, the resultant glass ceramics suffer loss of transparency due to crystallization. Using the levitation furnace, it is possible to produce amorphous glass beads from MgAl2O4 enriched with 25 wt% SiO2 without a container. The nanocrystalline ceramics synthesized from these glasses and the ISC glasses via the high-pressure route (CAU) are moderately transparent to translucent.

Ceramics doi: 10.3390/ceramics8040155

Authors: Kacper A. Prokop Sandrine Cottrino Vincent Garnier Gilbert Fantozzi Miłosz Siczek Krzysztof Rola Elżbieta Tomaszewicz Yannick Guyot Georges Boulon Małgorzata Guzik

This work highlights the feasible fabrication of translucent ceramics from un-doped and Nd3+-doped BaLaLiWO6 (BLLW) and BaLaNaWO6 (BLNW) cubic tungstates using the Spark Plasma Sintering (SPS) method. Ceramics were sintered using pure-phase, homogeneous powders with submicron particle sizes, obtained via the solid-state reaction method. The present study investigated the microstructural, structural, and spectroscopic properties of both un-doped and Nd3+-doped sintered specimens. All the ceramic materials exhibited certain drawbacks that significantly contributed to their low transparency in both sample types. However, initial spectroscopic tests on sintered translucent ceramics doped with Nd3+ ions revealed promising properties, comparable to those of the powdered samples. Therefore, we believe that producing higher-quality ceramics would improve their spectroscopic properties. For that, further optimization of the manufacturing conditions is necessary.

Ceramics doi: 10.3390/ceramics8040153

Authors: Nahyr Michelle Tercero-González Daniel Lardizábal-Gutiérrez Jorge Escobedo-Bretado Ivan Vásquez-Duarte Ricardo Beltran-Chacon Caleb Carreño-Gallardo

The growing energy demand in the residential sector, driven by the extensive use of air conditioning systems, poses serious environmental and economic challenges. A sustainable alternative is the use of efficient insulating materials derived from waste resources. This study presents the synthesis of glass–ceramic foams produced from recycled glass (90 wt%), pumice (5 wt%), and limestone (5 wt%), sintered at 800 °C for 10 min. The resulting foams exhibited a low apparent density of 684 kg/m3 and thermal conductivity of 0.09 W/m·K. These were incorporated into composite insulating panels composed of 70 wt% ceramic pellets and 30 wt% Portland cement, achieving a thermal conductivity of 0.18 W/m·K. The panels were evaluated in a 64.8 m2 social housing model located in Chihuahua, Mexico, using TRNSYS v.17 to simulate annual energy performance. Results showed that applying a 1.5-inch ceramic foam panel reduced the annual energy demand by 16.9% and the total energy cost by 14.7%, while increasing the panel thickness to 2 in improved savings to 18.4%. Compared with expanded polystyrene (EPS), which achieved 24.9% savings, the proposed ceramic panels offer advantages in fire resistance, durability, local availability, and environmental sustainability. This work demonstrates an effective, low-cost, and circular-economy-based solution for improving thermal comfort and energy efficiency in social housing.

Ceramics doi: 10.3390/ceramics8040154

Authors: Assel Darkhan Abibulla Anarbayev Begen Yessimov Tatyana Vakalova Viktor Stanevich Alina Molodykh

The development of the ceramic industry requires the creation of new innovative products with improved properties. Given the growing demand for high-quality finishing materials and the limited availability of traditional raw materials, the search for more efficient technologies for porcelain stoneware production is a relevant challenge. The aim of this study was to develop porcelain stoneware with enhanced performance characteristics. The research presents the results of a study aimed at improving the production technology of porcelain stoneware in Kazakhstan using local raw materials and microsilica. The raw materials from the Turkestan region were examined for their suitability for porcelain stoneware production. The influence of technological parameters (firing temperature, particle size) on the properties of porcelain stoneware was studied. New ceramic compositions with various microsilica contents, a by-product of silicon production, were investigated. Different compositions with varying raw material mixtures and microsilica content were prepared and fired at temperatures of 1100, 1150, and 1200 °C. The optimization of process parameters for producing porcelain stoneware in different compositions showed the degree of yield dependence on firing temperature and time as well as the effect of microsilica content. The temperature, time, and visually determined parameters at which different yield values were achieved were highlighted in different colors. The results showed that changes in the mixture composition and sintering temperature affect the quality of ceramic tiles. The final experimental conclusions demonstrated that the production of ceramic tiles containing up to 3% microsilica at a firing temperature of 1200 °C. The addition of microsilica increases the flexural strength of porcelain stoneware to 41 MPa (exceeding the standard), reduces water absorption to 0.023%, increases frost resistance to 107 cycles, and also enhances shrinkage. These findings open new prospects for the development of the domestic ceramic industry, the expansion of the product range, and the resolution of environmental issues.

Ceramics doi: 10.3390/ceramics8040152

Authors: Gurinder Pal Singh Joga Singh Abayomi Yusuf Kulwinder Kaur

Environmentally friendly materials with superior structural, physical, optical, and shielding capabilities are of great technological importance and are continually being investigated. In this work, novel multicomponent borate glasses with the composition xTiO2-10BaO-5Al2O3-5WO3-20Bi2O3-(60-x) B2O3, where 0 ≤ x ≤ 15 mol%, were produced via the melt-quenching technique. The increase in TiO2 content results in a decrease in molar volume and a corresponding increase in density, indicating the formation of a compact, rigid, and mechanically hard glass network. Elastic constant measurements further confirmed this behavior. FTIR analysis confirms the transformation of BO3 to BO4 units, signifying improved network polymerization and structural stability. The prepared glasses exhibit an optical absorption edge in the visible region, demonstrating their strong ultraviolet light blocking capability. Incorporation of TiO2 leads to an increase in refractive index, optical basicity, and polarizability, and a decrease in the optical band gap and metallization number; all of these suggest enhanced electron density and polarizability of the glass matrix. Radiation shielding properties were evaluated using Phy-X/PSD software. The outcomes illustrate that the Mass Attenuation Coefficient (MAC), Effective Atomic Number (Zeff), Linear Attenuation Coefficient (LAC) increase, while Mean Free Path (MFP) and Half Value Layer (HVL) decrease with increasing TiO2 at the expense of B2O3, confirming superior gamma-ray attenuation capability. Additionally, both TiO2-doped and undoped samples show higher fast neutron removal cross sections (FNRCS) compared to several commercial glasses and concrete materials. Overall, the incorporation of TiO2 significantly enhances the optical performance and radiation-shielding efficiency of the environmentally friendly glass system, making these potential candidates for advanced photonic devices and radiation-shielding applications.

Ceramics doi: 10.3390/ceramics8040151

Authors: Pardeep Kumar Gianchandani Enrico Fabrizio Bartolomeo Megna Manuela Ceraulo Francesco Baino

The transition toward a circular economy is one of the most pressing challenges and opportunities of our time, requiring fundamental shifts in how we produce, consume, and manage materials [...]

Ceramics doi: 10.3390/ceramics8040150

Authors: Sai Krishna Padamata Geir Martin Haarberg Gudrun Saevarsdottir

The electrochemical production of silicon from SiO2 in molten salts can reduce energy consumption and mitigate carbon emissions associated with the conventional carbothermic process. In this study, we compare the anodic behaviour of platinum, graphite, and tin oxide electrodes in molten CaCl2-NaCl-CaO-SiO2 at 850 °C using electrochemical methods including cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. Pt exhibited low oxygen evolution overpotentials and no significant currents before OER, compared to SnO2. An eight-hour potentiostatic electrolysis with a SnO2 anode and a graphite cathode yielded a Si-Sn deposit, indicating partial dissolution of the SnO2 anode during the electrolysis process. These results highlight the kinetic trade-off of SnO2 relative to Pt, and the risk of Sn contamination with extended electrolysis times. While SnO2 is unsuitable for production of high-purity Si, it remains a promising anode candidate for Si-Sn alloy formation.

Ceramics doi: 10.3390/ceramics8040149

Authors: Abdel Boughriet Grégory Tricot Bertrand Revel Viviane Bout-Roumazeilles Sandra Ventalon Michel Wartel

This research constitutes a novel experimental approach to valorizing an industrial by-product: the ‘brick’. Studies put emphasis on the importance of detailed structural characterization of brickminerals and their chemical evolution upon heating, contributing rationally to the design and development of new glass–ceramic forms that would be suitable for efficiently encapsulating radio-nuclides. The brick used is a complex material composed of metakaolinite, illite, sand and impurities such as rutile and iron oxides/hydroxides. Raw brick was first activated with a range of sodium hydroxide concentrations, and, second, cured at different temperatures from 90 °C to 1200 °C. Alkali-brick frameworks gradually decomposed during the firing, and turned into crystalline ceramic phases (analcime and leucite) embedded inside an amorphous silica-rich phase. After each heating stage, the cured-brick sample was exhaustively characterized by using a variety of advanced analytical techniques, including powder X-ray diffraction, ESEM/EDS microscopy and 29Si-27Al-MAS-NMR spectroscopy. Ultra-high magnetic field NMR (28.2 T) was used to distinguish and quantify Al(IV), Al(V) and Al(VI) configurations, and to better follow distinctive changes in 27Al environments of brickminerals under thermal effects. Glass-ceramized brick exhibited high specific density (~2.6 g·cm−3), high compactness and good corrosion resistance under static, mild and aggressive conditions, attesting to its high solidification and chemical durability.

Ceramics doi: 10.3390/ceramics8040148

Authors: Rafael G. Duque-Castro Diana Isabel Berrocal Melany Nicole Medina Pérez Luis Ernesto Castillero-Ortega Antonio Alberto Jaén-Ortega Juan Blandón Rodríguez Maria De Los Angeles Ortega-Del-Rosario

Additive manufacturing (AM) with clay and ceramic-based materials is gaining momentum as a sustainable alternative in construction, yet its advancement depends on bridging experimental practice with predictive modeling. This review synthesizes advances in mathematical formulations and numerical tools applied to clay, geopolymers, alumina, and related extrusion-based pastes. Classical rheological models, including the Bingham and Herschel–Bulkley formulations, remain central for characterizing yield stress, structuration, and flow stability. Meanwhile, finite element (FEM) and computational fluid dynamics (CFD) approaches are increasingly supporting predictions of deformation, shrinkage, drying, and sintering. Despite these advances, their application to natural clay systems remains limited due to heterogeneity, moisture sensitivity, and the lack of standardized constitutive parameters. Recent studies emphasize that validation is essential: rheometry, layer stability tests, in situ monitoring, and prototyping provide necessary calibration for reliable simulation. In parallel, parametric and generative design workflows, particularly through Rhino and Grasshopper ecosystems, illustrate how digital methods can link geometric logic, fabrication constraints, and performance criteria. Overall, the literature demonstrates a transition from isolated modeling efforts toward integrated, iterative frameworks where rheology, numerical simulation, and experimental validation converge to improve predictability, reduce trial-and-error, and advance scalable and sustainable clay- and ceramic-based AM.

Ceramics doi: 10.3390/ceramics8040147

Authors: Mohammad Hassan Shirani Bidabadi Manoj K. Mahapatra Kathy Lu

In this study, SiHfCN ceramics were synthesized from a single-source precursor obtained by reacting Durazane 1800 with tetrakis(dimethylamido)hafnium(IV) (TDMAH). In a separate preparation, Ti3C2 MXene was incorporated into this precursor to produce MXene-SiHfCN composite ceramics. The samples were pyrolyzed at 1000 °C and heat-treated at 1600 °C in N2 to investigate amorphous-to-crystalline transformations. Both SiHfCN and MXene-SiHfCN formed a single-phase amorphous structure after pyrolysis at 1000 °C. At 1600 °C, SiHfCN partially crystallized into α/β-Si3N4 and HfCxN1−x phases within an amorphous/crystalline Si3N4 matrix. In contrast, the MXene–SiHfCN matrix remained largely amorphous, evolving into SiOCN with localized Si2ON2 crystallization. Additional phases, including HfCxN1−x, Hf oxide/oxycarbide, and a Ti carbonitride-rich phase (TiC0.63N1.06O0.18Si0.99Hf0.11), were identified within the amorphous SiOCN. No SiC was detected in either system, indicating suppression of carbothermal reduction of Si3N4 up to 1600 °C in N2. While SiHfCN exhibited pronounced macroscopic cracks, MXene-SiHfCN showed no such large cracks, though local microscopic cracking was observed. These results demonstrate that Ti3C2 MXene incorporation stabilizes the amorphous matrix, modifies phase evolution, and mitigates severe cracking, offering new insights into non-oxide PDC nanocomposites for ultra-high-temperature applications.

Ceramics doi: 10.3390/ceramics8040146

Authors: Xiaoman Zhang Wangwang Xu Bipin Bhattarai Dominic A. Dalba Dilan M. Gamachchi Indeewari M. Karunarathne Yue Yu Nathan J. Pravda Ruotian Gong David Stalla Chong Zu W. J. Meng Andrew C. Meng

Aluminum scandium nitride (Al1−xScxN) is a promising ferroelectric material for non-volatile random-access memory devices and electromechanical sensors. However, adverse effects on polarization from electrical leakage are a significant concern for this material. We observed that the electrical conductivity of Al1−xScxN thin films grown on epitaxial TiN(111) buffered Si(111) follows an Arrhenius-type behavior versus the growth temperature, suggesting that point defect incorporation during growth influences the electronic properties of the film. Photoluminescence intensity shows an inverse correlation with growth temperature, which is consistent with increased non-radiative recombination from point defects. Further characterization using secondary ion mass spectrometry in a focused ion beam/scanning electron microscope shows a correlation between trace Ti concentrations in Al1−xScxN films and the growth temperature, further suggesting that extrinsic dopants or alloying components potentially contribute to the point defect chemistry to influence electrical transport. Investigation of the enthalpy of formation of nitrogen vacancies in Al1−xScxN using density functional theory yields values that are in line with electrical conductivity measurements. Additionally, the dependence of nitrogen-vacancy formation energy on proximity to Sc atoms suggests that variations in the local structure may contribute to the occurrence of point defects, which, in turn, can impact electrical leakage. Furthermore, we have demonstrated ferroelectric behavior through electrical measurements and piezoresponse force microscopy after dc bias poling of films in spite of electrical conductivity spanning several orders of magnitude. Although electrical leakage remains a challenge in Al1−xScxN, the material holds potential due to tunable electrical conductivity as a semiconducting ferroelectric material.

Ceramics doi: 10.3390/ceramics8040145

Authors: Valentina Rigano Dilshat U. Tulyaganov Konstantinos Dimitriadis Simeon Agathopoulos Francesco Baino

The crystallization behavior of the bioactive silicate glass “1d” was analyzed using non-isothermal conditions through differential scanning calorimetry (DSC). The plots carried out at different heating rates showed only one crystallization peak. The activation energy for crystallization was calculated through the equations proposed in the Kissinger and Matusita–Sakka models. The Johnson–Mehl–Avrami coefficient (n) was estimated by applying Ozawa and Augis–Bennet methods, resulting in a two-dimensional crystal growth. Crystalline phases which developed during high-temperature treatment were analyzed by X-ray diffraction and scanning electron microscopy. The activation energy for viscous flow was estimated to be 513 kJ/mol, which is lower than the activation energy for crystallization (539 kJ/mol). The Malek test highlighted that the crystallization process was more complex than a simple nucleation-growth mechanism. The sinterability parameter and Hruby coefficient showed the high stability of 1d glass against crystallization, which makes this bioactive material highly appealing for producing well-sintered products of biomedical interest, such as bioactive porous scaffolds for bone regeneration.

Ceramics doi: 10.3390/ceramics8040144

Authors: Yaroslav Meleshkin Anton Smirnov Marina A. Volosova Yuri Pristinskiy Thet Naing Soe Irina Reutova Nestor Washington Solís Pinargote

Using spark plasma sintering technology, SiC-TiB2-TiC ceramic composites with various graphene oxide content (0.15, 0.25, 0.5 vol.%) were manufactured, and their microstructure as well as physico-mechanical and tribological properties were studied. Ceramic composite with 0.25 vol.% of graphene oxide showed a relative density of 99.9%, fracture toughness of 6.3 MPa·m1/2, flexural strength of 583 MPa and Vickers hardness of 22.2 GPa. Moreover, this composite showed a coefficient of friction and wear rate of 0.53 and 1.92 × 10−6 mm3/N·m, respectively, under a load of 10 N. Similarly, under a load of 30 N, this composite showed a coefficient of friction and wear rate of 0.6 and 4.05 × 10−5 mm3/N·m, respectively. This research demonstrated that the addition of 0.25 vol.% of graphene oxide improved the physical–mechanical and tribological properties of ceramic composites based in the SiC-TiB2-TiC ternary system, which in turn makes this composite more promising for use, for example, as a cutting tool material.

Ceramics doi: 10.3390/ceramics8040143

Authors: Seon-Chil Kim Kwon Su Chon

Numerous studies aimed to validate new shielding materials with the transition of medical radiation-shielding tools toward eco-friendly materials. In this study, we assessed the feasibility of ceramic composites, recently adopted in aerospace for internal shielding, as candidates for medical applications. Specifically, three types of ceramic composite mixtures were examined: bismuth oxide-based (Bi2O3), cerium oxide-based (CeO2), and tantalum oxide-based (Ta2O5) ceramic composites. Two approaches—theoretical simulations and direct experiments—validated the performance under clinical conditions. Monte Carlo simulation results reveal that CeO2, with its high linear attenuation coefficient, exhibits the strongest theoretical shielding. In terms of density measurements, Ta2O5 composite sheets yielded the highest density (3.318 g/cm3), followed by CeO2 composites (3.228 g/cm3) and Bi2O3 composites (3.091 g/cm3). Although relatively slight differences in density were observed among the fabricated sheets, Ta2O5 composites tended to have slightly higher densities. However, Ta2O5 composites outperformed the other composites in direct clinical experiments. This discrepancy between the theoretical and experimental results highlights the influence of other factors, such as the energy characteristics of the materials and variations in the fabrication process. Overall, this study supports the development of eco-friendly radiation shields through theoretical and clinical validation.

Ceramics doi: 10.3390/ceramics8040142

Authors: Rahima Meziane Salim Benaissa Abdelbaki Cherouana Sofiane Bouheroum Khadidja Hoggas Said Meguellati Mohamed Hamidouche Gilbert Fantozzi

This work employs moiré interferometry to investigate the influence of sintering temperature and sandblasting on the optical and mechanical properties of magnesium aluminate spinel (MgAl2O4). S25CRX14 Spinel pellets were fabricated via Spark Plasma Sintering (SPS) at 1300 °C, 1350 °C, and 1400 °C. The sintered samples were subsequently analyzed before and after sandblasting. Moiré interferometry, a non-destructive and contactless technique based on the superposition of tow linear transmission gratings, has proven particularly suitable for detecting micro-defects in transparent materials. The analysis of moiré fringes provided essential insights into the presence and size of defects, enabling accurate quality assessment without altering the samples. Its high spatial resolution, allowed the detection of even low-contrast defects. The results confirmed that the sintering temperature and sandblasting significantly influenced the mechanical and optical properties of the S25CRX14 spinel samples. The specimens sintered at 1350 °C exhibited the highest light transmission and the superior hardness. In contrast, the samples sintered at 1400 °C showed a notable degradation in their optical and mechanical properties. In conclusion, the pellets sintered at 1350 °C demonstrated the most favorable overall performance. This study confirms that moiré interferometry is a straightforward, accurate, and highly effective method for evaluating transparent ceramics, with very low implementation costs.

Ceramics doi: 10.3390/ceramics8040141

Authors: Jean-Marc Tulliani

Engineered cementitious composites (ECCs) are fiber-reinforced materials with enhanced tensile strength, ultra-high ductility, crack resistance, and long-term durability. This review aims to explore the latest developments when combining ECC and 3D printing in depth. It will analyze the main technologies used, the specific properties of the materials employed, the results achieved so far, and the challenges still to be addressed for the wider deployment of these innovative solutions. The goal is to provide a comprehensive and up-to-date overview, highlighting the potential of this technology.

Ceramics doi: 10.3390/ceramics8040140

Authors: Daria Jóźwiak-Niedźwiedzka Paweł Lisowski Magdalena Osial Aneta Brachaczek Dariusz Alterman Alessandro P. Fantilli

This study investigates a comprehensive study on the mechanical and microstructural behavior of cementitious mortars modified with a combination of internal carbonation (via solid CO2), calcined clay as a ceramic pozzolanic additive, and bio-based sheep wool fibers. The investigation aimed to explore sustainable routes for enhancing mortar performance while reducing the environmental impact of cement production. A series of mortars incorporating various combinations of dry ice, calcined clay, and wool fibers was prepared and tested to evaluate compressive and flexural strength, porosity, pore size distribution, phase composition, and microstructural morphology. Results demonstrated that internal carbonation significantly promoted matrix densification and compressive strength, increasing fc by approximately 8% compared to the reference. The addition of calcined clay further improved microstructural compactness, reducing total pore volume by 12%, while the incorporation of wool fibers enhanced post-cracking toughness by over 40% despite a 15–30% decrease in compressive strength. SEM and TGA confirmed the formation of calcite and reduced portlandite content, consistent with carbonation and pozzolanic reactions. The findings underscore the potential and limitations of multicomponent eco-modified cement mortars. Optimizing the balance between internal carbonation, pozzolanic reaction, and fiber stability is a key to developing next-generation low-carbon composites suitable for durable and resilient construction applications.

Ceramics doi: 10.3390/ceramics8040139

Authors: Honghui Wang Pengcheng Zhang

This study comparatively investigates the effects of vacuum sintering and traditional sintering on the structure and electrical properties of lead zirconate titanate (PZT) 5H (PZT-5H) piezoelectric ceramics. The density of the vacuum-sintered ceramics increases from 7.67 g/cm3 (for traditionally sintered ceramics) to 7.98 g/cm3. Importantly, the dielectric constant (εr), remnant polarization (Pr), planar electromechanical coupling coefficient (kp), and piezoelectric coefficient (d33) for the PZT-5H ceramics increase by 35%, 20%, 9%, and 12%, respectively, when vacuum sintering is employed instead of traditional sintering. Over a temperature range from room temperature to 180 °C, the d33 variation measured by the resonant method is only about 4% for the vacuum-sintered PZT-5H ceramics. High-temperature impedance spectroscopy analysis reveals that vacuum sintering reduces the hole concentration in PZT-5H ceramics, leading to significant improvements in their dielectric and piezoelectric performance. This research demonstrates that vacuum sintering is a simple and effective method to enhance the density, dielectric, and piezoelectric properties of PZT-5H ceramics.

Ceramics doi: 10.3390/ceramics8040138

Authors: Stefan Ioan Voicu Andreea Madalina Pandele Adrian Ionut Nicoara Iulian Vasile Antoniac Madalina Oprea Cristian Bica

Implant-associated infections remain a major clinical challenge, often leading to implant failure, revision surgery, and increased healthcare burden. Systemic antibiotic administration is limited by poor local bioavailability and systemic side effects, highlighting the need for localized drug-delivery systems that can simultaneously support tissue integration and prevent bacterial colonization. This study aimed to develop and characterize a novel generation of chitosan membranes loaded with hydroxyapatite–clindamycin phosphate (CS/HA-CLY) for localized infection prevention at implantation sites. The composite membranes’ physicochemical characteristics were analyzed using ATR FT-IR, XPS, SEM, XRD, and contact angle measurements. Furthermore, the in vitro biomineralization potential was assessed employing the Taguchi method, while the in vitro release of clindamycin phosphate was examined through UV-Vis spectrophotometry. The CS/HA-CLY membranes exhibited improved wettability, drug release behavior, and biomineralization ability compared to neat CS. These results suggest that the developed composite membranes could successfully combine antibacterial efficacy and biocompatibility, supporting their potential as multifunctional biomaterials for preventing implant-related infections while promoting tissue integration. These findings provide a promising basis for further biological assays and in vitro evaluation.

Ceramics doi: 10.3390/ceramics8040137

Authors: Alina Zurnachyan Abraam Ginosyan Roman Ivanov Irina Hussainova Sofiya Aydinyan

High-entropy materials have emerged as promising candidates for high-temperature structural, magnetic, and electrochemical applications due to their unique combination of compositional complexity, thermal stability, and tailored functionality. In this study, self-propagating high-temperature synthesis (SHS) was employed to fabricate high-entropy composite in a Ti–Cr–Mn–Co–Ni–Al–C multicomponent system with a focus on elucidating the effect of titanium content on the combustion parameters, as well as on the phase and structure formation patterns of the resulting materials. In situ profiling enables evaluating the maximum combustion temperature of 1560 °C, combustion wave propagation velocity ranging from 0.22 to 4.3 mm/s depending on titanium content, and heating and cooling rates of 300–2000 °C/s and 3 °C/s during synthesis. The synthesized powders exhibited a bimodal particle size distribution, with ~90% of particles below 25 μm and a D50 of 5.38 μm. Post-synthesis densification via spark plasma sintering (SPS) at 1250 °C under 45 MPa yielded dense bulk samples, which exhibited a high relative density and high Vickers microhardness of 1270 ± 35 HV10 attributed to fine TiC dispersion and secondary carbide formation. Thermogravimetric analysis performed under air flow with a heating rate of 20 °C/min showed enhanced thermal stability for both the powder and the sintered bulk. These findings demonstrate the efficacy of SHS for rapid, energy-efficient fabrication of high-entropy composites and underscore the critical role of composition in tailoring their structural and mechanical properties.

Ceramics doi: 10.3390/ceramics8040136

Authors: Salma El-Azab Sichao Chen Julie M. Schoenung Alexander D. Dupuy

Despite significant interest in their functional properties, the mechanical behavior of high-entropy oxides (HEOs) is not well studied, particularly at elevated temperatures. Bulk (Co,Cu,Mg,Ni,Zn)O (transition metal (TM)-HEO) samples were deformed under compression at applied stresses and temperatures ranging from 5 to 31 MPa and 600 to 850 °C, respectively. All of the deformation conditions result in creep stress exponents of n < 3, indicating that TM-HEO exhibits superplastic deformation. A transition from structural to solution-precipitation-based superplasticity is observed during deformation above 650 °C. Additionally, TM-HEO exhibits shear-thickening behavior when deformed at stresses above 9 MPa. The formation and behavior of a Cu-rich tenorite secondary phase during deformation is identified as a key factor underpinning the deformation mechanisms. The microstructure and phase state of TM-HEO before deformation also influenced the behavior, with finer grain sizes and increasing concentrations of Cu-rich tenorite, resulting in the increased prevalence of solution-precipitation deformation. While complex, the results of this study indicate that TM-HEO deforms through known superplastic deformation mechanisms. Superplasticity is a highly efficient manufacturing method and could prove to be a valuable strategy for forming HEO ceramics into complex geometries.

Ceramics doi: 10.3390/ceramics8040135

Authors: Layla A. Abu-Naba’a Saleh N. Almohammed Tareq A. Ziyad

Transparent CAD/CAM monolithic ceramics are increasingly used in dentistry due to their combination of high strength, esthetics, and durability, achieved through high yttria content and multilayered systems. This study evaluates the mechanical behavior of four widely used CAD/CAM ceramics, correlating their performance with microstructural characteristics. Bar-shaped specimens (n = 10 per material, for each test) of ZOLID® FX ML (ZF), IPS E.MAX® CAD (MC), E.MAX® ZIRCAD (ZM), and KAT-ANA® STML (KS) (all A2 shade) were prepared and sintered according to manufacturers’ protocols. Flexural strength and elastic modulus were measured using three-point bending, and Vickers hardness was determined separately. Statistical normality was confirmed with the Kolmogorov–Smirnov test. Flexural strength ranged from 252.8 ± 39.8 MPa (MC) to 547.6 ± 125.7 MPa (ZM), elastic modulus from 65.8 ± 6.5 GPa (MC) to 94.1 ± 5.8 GPa (KS), and hardness from 4.2 ± 0.2 GPa (MC) to 9.6 ± 0.6 GPa (ZF). High-elastic-modulus materials (KS, ZM) can better resist deformation under occlusal loads, improving long-term stability of posterior crowns, bridges, and implant-supported restorations. High hardness (ZF) provides superior wear resistance and preserves occlusal anatomy over time, making it suitable for thin-shell restorations and high-stress functional surfaces. Materials with lower modulus and hardness (MC) are more suitable for intra-coronal restorations or thin veneers where stress shielding and material compliance are advantageous. These findings support material selection based on mechanical demands, and further clinical studies are needed to confirm long-term performance.

Ceramics doi: 10.3390/ceramics8040134

Authors: Jonathan Oti Mansour Ebailila Khaled Ehwailat John Kinuthia

The utilisation of magnesium oxide-based binders (M) as an alternative to hydrated calcium silicate materials is a promising avenue for binding methodologies. However, the efficacy of using silica fume (S) as a co-binder with magnesium oxide in sulphate soil stabilisation, along with their ideal blending ratio, has yet to be unveiled. Therefore, an array of artificial sulphate soil specimens was fabricated, each featuring varying combinations of magnesium oxide and silica fume. These specimens were subsequently subjected to comprehensive testing, including unconfined compressive strength (UCS) test, linear expansion test, thermogravimetric analysis, and X-ray diffraction analysis. The outcomes demonstrated that the co-utilisation of silica fume and magnesium oxide significantly improves the compressive strength and linear expansion of sulphate soil, and such an improvement was more efficacious at a stoichiometric amount of 5% magnesium oxide and 5% silica fume (5M5S). This outperforming threshold, characterised by the highest UCS (1834 kN/m2) and minimal expansion (0.2%), occurred through the consumption of surplus brucite and the formation of further magnesium silicate hydrate.

Ceramics doi: 10.3390/ceramics8040133

Authors: Mansour Ebailila Khaled Ehwailat Jonathan Oti

Sulfate soil stabilisation, while offering technical benefits for infrastructure, is a challenging process, complicated by the nucleation of ettringite, an expansive mineral that can cause soil deterioration. This study was undertaken to elucidate the synergistic effect of lime and metakaolin on the physico-mechanical performance of high-sulfate-bearing soil. The binder content in the stabilised specimens was fixed at 20 wt%, and metakaolin was used to partially substitute lime at different substitution levels. The physico-mechanical investigation revealed that supplementation of lime with metakaolin had a promotional effect on the unconfined compressive strength and swelling potential. The threshold of this effect was obtained by a binary blend of 7.5L–12.5MK, where the UCS was increased fourfold, while the swelling potential was reduced to a near-zero magnitude of 0.33%. This superior performance is due to the fineness and high reactivity of metakaolin, as both limit the nucleation of ettringite and promote the neoformation of further hydrated compounds, thus yielding a denser interlocked system and increasing its resistance to water soaking.

Ceramics doi: 10.3390/ceramics8040132

Authors: Chengjian Li Frank Kern Lianmeng Liu Christopher Parr Andreas Börger Chunfeng Liu

Garnet-type Li7La3Zr2O12 (LLZO) is a solid electrolyte candidate for ASSLBs, owing to its wide electrochemical window and intrinsic safety. Yet phase-pure LLZO remains difficult because secondary phases form, and the transition towards the tetragonal phase, aliovalent doping, mitigates these issues. Still, the phase formation pathway is not fully understood. Here, we present comparative in situ and ex situ studies of Nb- and Ta-doped LLZO (LLZNO and LLZTO) that were synthesized by a solid-state reaction. In situ/ex situ XRD reveals that the lithium precursor dictates the reaction path: differing decomposition temperatures of the lithium precursor define reaction windows that control cubic-phase purity and particle morphology. In air, limited Li diffusion favors oxycarbonates and pyrochlore, necessitating 950–1050 °C to achieve phase-pure cubic LLZO. Under N2, faster Li availability and diffusion enable uniform nucleation and a route to cubic LLZO without detectable secondary phases. These findings demonstrate the coupled effects of temperature, precursor, dopant, and atmosphere, guiding process optimization and scalable production.

Ceramics doi: 10.3390/ceramics8040131

Authors: Miguel Pérez Oscar G. de Lucio Alejandro Mitrani Carlos Peraza Lope Wilberth Cruz Alvarado Hugo Sobral Ciro Márquez Herrera Soledad Ortiz Ruiz

The great city of Mayapan has experienced a technological change in pottery making, and our results confirm a shift in the raw materials and possibly the potters’ knowledge about them. The dynamics of change during the Postclassic period in the Maya area are reflected in the material changes used to make pottery. A comprehensive analysis was conducted on a collection of 248 pottery items from the archaeological site of Mayapán in Yucatán, Mexico, dating from the Middle Preclassic to Postclassic periods (700 BC–1500 CE). Non-invasive methods were used for the entire pottery set, including X-ray fluorescence (XRF) and fiber-optic reflectance spectroscopy (FORS). Additionally, for a representative subset, minimally invasive techniques such as inductively coupled plasma optical emission spectrometry (ICP-OES) and laser-induced breakdown spectroscopy (LIBS) were employed. The resulting data enabled the identification of materials used in the pottery’s manufacture. The elemental composition of the objects was determined, revealing correlations between elements such as Si with Al that yield a R2 factor of 0.94. The results indicate the presence of smectite clays, carbonates, and iron oxides. The results show that a higher proportion of carbonates was found in the pieces from the Postclassic period compared to those from the Preclassic period, which may be associated with a change in the manufacturing process. Likewise, the Postclassic pieces are distinguished by a greater contribution of the Mg-OH signal, unlike the Preclassic and Classic, which show a greater contribution of the Al-OH group. The implications for the technological knowledge of the potters suggest the use of different technologies across various periods and material changes driven by shifts in political and economic relations in the city and the northern plains.

Ceramics doi: 10.3390/ceramics8040130

Authors: Mikhail Palatnikov Olga Shcherbina Nadezhda Fokina Maxim Smirnov Elena Zelenina Sofja Masloboeva Diana Manukovskaya

Fine powders of erbium niobate-tantalates ErNbxTa1−xO4 (x = 0; 0.1; 0.3; 0.5; 0.7; 0.9; 1) have been synthesized by the liquid-phase method in this study. Ceramic samples have been prepared using conventional sintering from these powders. Rietveld refinement of XRD patterns of polycrystals determined the phase composition and clarified the parameters of the phase structure of ErNbxTa1−xO4 solid solutions depending on the Nb/Ta ratio. The morphological features of the microstructure of erbium niobate-tantalate ceramics have been studied. Their mechanical properties, strength characteristics (Young’s modulus, microhardness) and critical stress intensity factor of the first kind KIC have been estimated. The photoluminescent properties of ceramic solid solutions of erbium niobate-tantalates depending on the composition have been studied. Dark and photoinduced toxicity of finely dispersed ErNbO4 powders have been studied in relation to Gram-positive, Gram-negative and spore-forming microorganisms. The best indicators of antibacterial activity of ErNbO4 have been demonstrated in relation to Gram-positive cells of Micrococcus sp. The discovered properties open up the possibility of not only traditional use as functional materials, but also the use of these materials for disinfection of surfaces, water and biological tissues.

Ceramics doi: 10.3390/ceramics8040129

Authors: Seyed Ali Mostafavi Moghaddam Hamid Mojtahedi Amirhossein Bahador Lotfollah Kamali Hakim Hamid Tebyaniyan

Background: Maxillomandibular bone defects present a complex challenge in regenerative medicine due to anatomical and functional intricacies. Calcium phosphate (CP)-based biomaterials have emerged as promising bone graft substitutes due to their biocompatibility, osteoconductivity, and bioactivity. Aim: This Review highlights recent clinical and experimental advancements in CP-based biomaterials for maxillomandibular bone regeneration, bridging the gap from bench to bedside. Method: An in vitro, in vivo, and clinical literature review was conducted to evaluate the performance of CP ceramics, including hydroxyapatite (HA), tricalcium phosphate (TCP), biphasic ceramics, and novel composites with polymers, growth factors, and nanoparticles. Results: Calcium phosphate-based biomaterials demonstrate excellent bone regeneration potential, with Beta-tricalcium phosphate (β-TCP) and HA being the most widely utilized. Composite scaffolds and 3-dimensional (3D)-printed constructs show enhanced mechanical properties and biological integration. Clinical trials have confirmed the safety and efficacy of CP-based materials, yielding promising outcomes in osteoconduction and defect healing. However, limitations persist regarding mechanical strength and long-term degradation profiles. Conclusions: CP-based biomaterials offer significant clinical promise for maxillomandibular bone regeneration. Continued advancements in scaffold design and biofunctionalization are crucial for overcoming current limitations and fully realizing their therapeutic potential.

Ceramics doi: 10.3390/ceramics8040128

Authors: Juan Li Jiwen Xu Guisheng Zhu Xianjie Zhou Fei Shang Huarui Xu

NiO-based hole-transport layers are crucial for high-efficiency perovskite solar cells. An industrial deposition method of NiO films is magnetron sputtering using ceramic targets. NiO targets doped with Li contents at 1%, 3%, and 5% were designed, and the doping contents and sintering temperatures were investigated. All the targets have a face-centered cubic phase, dense microstructure, and an average size of a few microns. The NLO targets sintered at an optimal temperature of 1400 °C exhibited high relative density (>98%) and low resistivity (<6 Ω∙cm). These results pave the way for depositing NiO-based hole-transport layer by magnetron sputtering.

Ceramics doi: 10.3390/ceramics8040127

Authors: Omar Zahhaf Giulia D’Ambrogio François Grasland Guilhem Rival Minh-Quyen Le Pierre-Jean Cottinet Jean-Fabien Capsal

This work presents a comprehensive study on the synthesis and application of Al2O3 fibers derived from an ammonium aluminum carbonate hydroxide (AACH) precursor. Through a hydrothermal route, the influence of critical synthesis parameters, including aluminum nitrate and urea concentrations, reaction temperature and time, and stirring conditions, on fiber morphology and aspect ratio was systematically investigated. The as-synthesized AACH fibers were subsequently converted into thermodynamically stable α-alumina fibers via controlled annealing. These high-aspect ratio alumina fibers were incorporated into polydimethylsiloxane (PDMS) to produce electrically insulating, thermally conductive composites. The thermal performance of fiber-filled composites was benchmarked against that of particle-filled counterparts, with the former exhibiting significantly enhanced thermal conductivity. Furthermore, the dielectrophoretic alignment of alumina fibers led to an additional increase in thermal conductivity, underlining the importance of high-aspect ratio fillers. This study uniquely combines the controlled synthesis of alumina fibers with their incorporation and alignment in a polymer matrix, presenting a novel and effective approach for engineering anisotropic, thermally conductive, and electrically insulating composite materials. Dielectrophoretic alignment of α-Al2O3 fibers synthesized through optimized hydrothermal conditions and incorporated into PDMS composites deliver over 95 % higher thermal conductivity than spherical fillers.

Ceramics doi: 10.3390/ceramics8040126

Authors: Thomas Hanemann Martin Ade Emine Cimen Julia Schoenfelder Kirsten Honnef Matthias Wapler Ines Ketterer

Barium strontium titanates (Ba1−xSrxTiO3, BST) with varying barium-to-strontium ratios were synthesized by the solid-state route (SSR) as well as by the sol–gel process (SGP). In the case of the SSR, the strontium amount x was varied from 0.0 to 0.25 in 0.05 steps, due to the enhanced synthetic effort, and in the case of the SGP, x was set only to 0.05, 0.15, and 0.25. The resulting properties after synthesis, calcination, and sintering, like particle size distribution, specific surface area, particle morphology, and crystalline phase were characterized. The expected tetragonal phase, free from any remarkable impurity, was found in all cases, and irrespective of the selected synthesis method. Pressed pellets were used for the measurement of the temperature and frequency-dependent relative permittivity enabling the estimation of the Curie temperatures of all synthesized BSTs. Irrespective of the selected synthesis method, the obtained Curie temperature drops with increasing strontium content to almost identical values, e.g., in the case of x = 0.15, a Curie temperature range 95–105 °C was measured. Thin BST films could be deposited on different substrate materials applying electrophoretic deposition in a good and reliable quality according to the Hamaker equation. The properties of the BSTs obtained by the simpler solid-state route are almost identical to the ones yielded by the more complex sol–gel process. In future, this result allows for a possible wider usage of BST perovskites for ferroelectric and piezoelectric devices due to the easy synthetic access by the solid-state route.

Ceramics doi: 10.3390/ceramics8040125

Authors: Jorge I. Fajardo César A. Paltán Marco León Annie Y. Matute Ana Armas-Vega Rommel H. Puratambi Bolívar A. Delgado-Gaete Silvio Requena Alejandro Benalcazar

We synthesized the current evidence from the literature and conducted a 2 × 3 factorial experiment to quantify the impact of thermocycling on the Vickers microhardness (HV) of dental CAD/CAM materials: VITA ENAMIC (VE, polymer-infiltrated ceramic network) and CERASMART (CS, nanofilled resin-matrix). Sixty polished specimens (n = 10 per Material × Cycles cell; 12 × 2 × 2 mm) were thermocycled at 5–55 °C (0, 10,000, 20,000 cycles; 30 s dwell, ≈10 s transfer) and tested as HV0.3/10 (300 gf, 10 s; five indentations/specimen with standard spacing). Assumptions regarding the model residuals were met (Shapiro–Wilk W ≈ 0.98, p ≈ 0.36; Levene F(5,54) ≈ 1.12, p ≈ 0.36), so a two-way ANOVA (Type II) with Tukey’s HSD post hoc (α = 0.05) was applied. VE maintained consistently higher HV than CS at all cycle levels and showed a smaller drop from baseline: VE (mean ± SD): 200.2 ± 10.8 (0), 192.4 ± 13.9 (10,000), and 196.7 ± 9.3 (20,000); CS: 60.8 ± 6.1 (0), 53.4 ± 4.7 (10,000), and 62.1 ± 3.8 (20,000). ANOVA revealed significant main effects from the material (η2p = 0.972) and cycles (η2p = 0.316), plus a Material × Cycles interaction (η2p = 0.201). Results: Thermocycling produced material-dependent changes in microhardness. Relative to baseline, VE varied by −3.9% (10,000) and −1.7% (20,000), while CS varied by −12.2% (10,000) and +2.1% (20,000); from 10,000→20,000 cycles, microhardness recovered by +2.2% (VE) and +16.3% (CS). Pairwise comparisons were consistent with these trends (CS decreased at 10,000 vs. 0 and recovered at 20,000; VE only showed a modest change). Conclusions: Thermocycling effects were material-dependent, with smaller losses and better retention in VE (PICN) than in CS. These results align with the literature (resin-matrix/hybrids are more sensitive to thermal aging; polished finishes mitigate losses). While HV is only one facet of performance, the superior retention observed in PICN under thermal challenge suggests the improved preservation of superficial integrity; standardized reporting of aging parameters and integration with wear, fatigue, and adhesion outcomes are recommended to inform indications and longevity.

Ceramics doi: 10.3390/ceramics8040124

Authors: Van Thi Thanh Tran Shusei Yamashita Hideaki Sano Osamu Nakagoe Shuji Tanabe Kai Kamada

This study reports the development of electrospun poly(methyl methacrylate) (PMMA) fiber mats incorporating ibuprofen (IBU)-intercalated layered double hydroxides (LDH) for enhanced transdermal drug delivery systems (TDDS). IBU, in its anionic form, was successfully intercalated into LDH, which possesses anion exchange capabilities, and subsequently embedded into PMMA fibers via electrospinning. In vitro drug release experiments demonstrated that UPMMA–LDH–IBU fibers exhibited significantly higher IBU release than PMMA–IBU controls. This enhancement was attributed to the improved hydrophilicity and water absorption imparted by the LDH, as confirmed by contact angle and water uptake measurements. Furthermore, artificial skin permeation tests revealed that the UPMMA–LDH–IBU fibers maintained comparable release rates to those observed during buffer immersion, indicating that the rate-limiting step was the diffusion of IBU within the fiber matrix rather than the interface with the skin or buffer. These findings highlight the critical role of LDH in modulating drug release behavior and suggest that UPMMA–LDH–IBU electrospun fiber mats offer a promising and efficient platform for advanced TDDS applications.

Ceramics doi: 10.3390/ceramics8040123

Authors: Apichai Maneenacarith Nantawan Krajangta Thanasak Rakmanee Awiruth Klaisiri

This study investigated the effect of piranha solution etching duration on the shear bond strength of zirconia ceramics bonded to resin cement, comparing it to conventional sandblasting treatment. Fifty fully sintered zirconia specimens (6.0 mm diameter, 4.0 mm thickness) were prepared and randomly divided into five groups (n = 10): sandblasting control and piranha solution treatment for 1, 2, 3, and 4 min. Piranha solution was prepared by mixing 98% H2SO4 and 35% H2O2 in a 3:1 ratio. All specimens were bonded to resin composite cylinders using dual-cure resin cement. Shear bond strength testing was performed using a universal testing machine at a 0.5 mm/min crosshead speed. Failure modes were analyzed using a stereomicroscope and classified as adhesive, cohesive, or mixed failures. One-way ANOVA revealed significant differences between groups (p < 0.05). Tukey’s post hoc test showed that 1-min piranha treatment produced significantly lower bond strength (7.64 ± 2.02 MPa) compared to all other groups. The 2-min (15.17 ± 2.79 MPa), 3-min (14.99 ± 3.27 MPa), and 4-min (18.34 ± 3.15 MPa) piranha treatments showed no significant differences compared to sandblasting (15.41 ± 2.61 MPa). Failure mode analysis revealed 100% adhesive failures for the 1-min group, while all other groups showed 80% adhesive and 20% mixed failures. Piranha solution treatment duration significantly affected zirconia bonding performance. While 1-min treatment proved inadequate, 2–4 min treatments achieved bond strengths comparable to sandblasting. The findings suggest that piranha solution treatment for 2–4 min represents a viable alternative to sandblasting for zirconia surface preparation, with the 2-min protocol being the most efficient choice for clinical application.

Ceramics doi: 10.3390/ceramics8040122

Authors: Mohammad Zaki Daoud Layla A. Abu-Naba’a Rami Al Fodeh

Translucency and color stability are key factors for the long-term success of dental ceramics. The aim was to compare the translucency parameter (TP) and color stability (ΔE) of CAD/CAM ceramics, including a lithium disilicate (E; IPS e.max CAD), a zirconia-reinforced lithium-silicate (S; VitaSuprinity), and a zirconia-based ceramic (Z; Ceramill Zolid HT+), before and after low-grade hydrothermal aging (134 °C and 2 bars for 20 h). Ninety disks (n = 30/group, A2, 1.2 ± 0.02 mm) were fabricated and their L*, a*, and b* values were recorded against black and white backgrounds to calculate TP, contrast ratio (CR), and opacity (OP). ANOVA, Bonferroni post hoc, and paired t-tests (α = 0.05) showed that after aging, the Z group showed ↓L and ↑a values; the E group showed ↓L with ↑ a and b; and the S group showed only ↑a. All ceramics exhibited ΔE values below the clinical acceptability threshold of 3.7. E presented the highest TP, whereas Z demonstrated the highest CR and masking ability. Aging significantly increased CR and OP but did not alter TP. Within the limitations of this study, all tested ceramics maintained clinically acceptable shade stability and translucency, with E showing superior initial translucency and Z offering improved masking potential.

Ceramics doi: 10.3390/ceramics8040121

Authors: Dongdong Zhang Haozhe Li Yu Liu Jingyu Jiang Yali Gao

In this paper, 316 stainless steel/TiC coatings with different LaB6 contents (0%, 2%, 4%, 6%) were prepared on the surface of 45 steel by laser cladding technology. The effects of the LaB6 content on the phase composition, microstructure, microhardness, and wear resistance of the coatings were studied. The results show that without the LaB6 addition, the coating is composed of Austenite and TiC phases, with defects such as pores and cracks, and the microstructure is mainly equiaxed grains. With the addition of LaB6, Fe-Cr phases are formed in the coating, and the microstructure transforms into columnar grains and dendritic grains. The grains are first refined and then coarsened, among which the coating with 4% LaB6 (C4) has the smallest grain size. The experimental results indicate that the microhardness of the coatings first increases and then decreases with the increase in the LaB6 content, and the C4 coating has the highest microhardness (594HV0.2). The wear rate shows the same variation trend. The C4 coating has the lowest wear rate and the best wear resistance. This is attributed to the synergistic effect of the fine grain strengthening and TiC particle dispersion strengthening.

Ceramics doi: 10.3390/ceramics8040120

Authors: Toshihiro Ishikawa

The mass transfer phenomenon of contained impurities causes differences in the morphologies, densification processes, and heat resistance of ceramics. Of these, in this paper, differences in the heat resistance of ceramic fibers are discussed. Third-generation SiC polycrystalline fibers demonstrated excellent heat resistance. However, at temperatures above 1800 °C, sintered fiber (Tyranno SA) and non-sintered fiber (Hi-Nicalon Type S) showed remarkable differences in heat resistance. At temperatures above 1800 °C, the non-sintered fiber underwent structural changes, including the formation of a surface carbon layer and abnormal SiC grain growth, whereas the sintered fiber maintained its stable polycrystalline structure. Until now, these differences and a detailed description of them have not been discussed. Here, we first explain the dramatic differences in heat resistance that occurred at high temperatures in relation to the mass transfer of excess carbon. Our findings should be widely used for the development of much more stable structures and for the long-term use of materials at higher temperatures in applications such as airplane engines and turbines.

Ceramics doi: 10.3390/ceramics8040119

Authors: Yana Suchikova Serhii Nazarovets Marina Konuhova Anatoli I. Popov

Binary oxide ceramics have emerged as key materials in solar energy research due to their versatility, chemical stability, and tunable electronic properties. This study presents a comparative analysis of seven prominent oxides (TiO2, ZnO, Al2O3, SiO2, CeO2, Fe2O3, and WO3), focusing on their functional roles in silicon, perovskite, dye-sensitized, and thin-film solar cells. A bibliometric analysis covering over 50,000 publications highlights TiO2 and ZnO as the most widely studied materials, serving as electron transport layers, antireflective coatings, and buffer layers. Al2O3 and SiO2 demonstrate highly specialized applications in surface passivation and interface engineering, while CeO2 offers UV-blocking capability and Fe2O3 shows potential as an absorber material in photoelectrochemical systems. WO3 is noted for its multifunctionality and suitability for scalable, high-rate processing. Together, these findings suggest that binary oxide ceramics are poised to transition from supporting roles to essential components of stable, efficient, and environmentally safer next-generation solar cells.

Ceramics doi: 10.3390/ceramics8030118

Authors: Chuyue Yang Xiaoqiang Liu

Zirconia is widely used in prosthodontics due to its excellent biocompatibility, mechanical properties, and esthetic characteristics. This article reviews the fundamentals of sintering zirconia for prosthodontic applications. Various sintering techniques, including conventional, spark plasma, high-speed, and microwave sintering, are discussed regarding their influence on translucency, strength, and microstructure. This review aims to provide a comprehensive reference for the sintering methods of zirconia currently used or may be used for dental prosthodontics.

Ceramics doi: 10.3390/ceramics8030116

Authors: Luigi Acampora Giulia Costa Iason Verginelli Francesco Lombardi Claudia Mensi Simone Malvezzi

In line with circular economy principles and the reduction of primary material exploitation, waste-to-energy (WtE) by-products such as bottom ash (BA) are increasingly being used as raw materials in cement and ceramics manufacturing. However, it is critical to verify that the final product presents not only adequate technical properties but also that it does not pose negative impacts to the environment and human health during its use. This study investigates the environmental compatibility of the use of ceramic porcelain stoneware tiles manufactured with BA as partial replacement of traditional raw materials, with a particular focus on the leaching behavior of the tiles during their use, and also after crushing to simulate their characteristics at their end of life. To evaluate the latter aspect, compliance leaching tests were performed on crushed samples and compared with Italian End-of-Waste (EoW) thresholds for the use of construction and demolition waste as recycled aggregates. Whereas, to assess the environmental compatibility of the tiles during the utilization phase, a methodology based on the application of monolithic leaching tests to intact tiles, and the evaluation of the results through multi-scenario human health risk assessment and the analysis of the main mechanisms governing leaching at different stages, was employed. The results of the study indicate that the analyzed BA-based tiles showed no significant increase in the release of potential contaminants compared to traditional formulations and fully complied with End-of-Waste criteria. The results of the monolith tests used as input for site-specific risk assessment, simulating worst-case scenarios involving the potential contamination of the groundwater, indicated negligible risks to human health for both types of tiles, even considering very conservative assumptions. As for differences in the release mechanisms, tiles containing BA exhibited a shift toward depletion-controlled leaching and some differences in early element release compared to the ones with a traditional formulation.

Ceramics doi: 10.3390/ceramics8030117

Authors: Hongfei Shao Ying Wang Jiahe Song Liwen Lei Xia Liu Xuejun Hou Jinyong Zhang

Due to its good thermal conductivity and small thermal expansion coefficient, aluminum nitride (AlN) is an excellent material for thermal shock resistance. Recently, carbon (C) doping has emerged as a potential strategy for tailoring the properties of AlN, but its effects on the mechanical properties and thermal conductivity of AlN remain unclear. In the present study, the mechanical properties and thermal conductivity of C-doped AlN (C@AlN) with various C-doping densities were investigated using first-principles calculations based on density functional theory. The results suggest that C doping often leads to an increase in the c lattice constant. When the C-doping concentration reaches 12.5%, the structural symmetry of 4C@AlN is fully broken. In addition, as the C-doping density increases, the strength and stiffness of C@AlN generally decrease while the ductility increases. Moreover, the thermal conductivity of C@AlN generally decreases as the C-doping density increases, mainly because of the structural distortion. Meanwhile, as the C-doping density reaches 12.5%, the thermal conductivity of 4C@AlN anomalously increases, due to the symmetry breakage.

Ceramics doi: 10.3390/ceramics8030115

Authors: Patrik Sokola Tina Skalar Pavel Šiler Jan Blahut Michal Kalina Peter Veteška Petr Ptáček

The stability of ceramic suspensions is a key factor in the preparation and shaping of ceramic bodies. The presented work offers an experimental determination of ceramics suspensions stability using the LUMiSizer analytical centrifuge, focusing on kinetic behaviour using transmission profiles and instability indexes. Multiple ceramic systems comprising corundum, metakaolin, and zirconia suspensions were experimentally examined under varying solid contents, dispersant dosages, and additive concentrations. Results showed that highly loaded corundum suspensions with dispersant (Dolapix CE64) achieved excellent stability, with an instability index below 0.05. Compared to classical sedimentation tests, which are time-consuming and not highly sensitive, LUMiSizer offers a suitable alternative by guaranteeing correct kinetic data and instability indexes indicating suspension behaviour using centrifugal force. Comparisons of the LUMiSizer results and data obtained using the modified Stokes law confirmed increased terminal velocities in experiments with metakaolin suspensions, indicating the sensitivity of the centrifuge to the effect of dispersion medium shape. The influence of porogen (waste coffee grounds) on the stability of corundum suspensions was also investigated, followed by slip casting to create and characterize a ceramic body, confirming the possibility of shaping based on stability results. Furthermore, instability indices are suggested as a rapid, quantitative method for comparing system stability and as an auxiliary criterion to the rheological measurements. Optimal dispersant concentration for zirconia-based photocurable suspensions was identified as 8.5 wt.%, which minimized viscosity and, at the same time, assured maximal kinetic stability. Integrating the LUMiSizer analytical centrifuge with standard methods, including sedimentation tests and rheological measurements, highlights its value as a powerful tool for characterizing and optimizing ceramic suspensions.

Ceramics doi: 10.3390/ceramics8030114

Authors: Rafael Shakirzyanov Sofiya Maznykh Yuriy Garanin Malik Kaliyekperov

The study of the relationship between the composition and mechanical properties of structural ceramics based on zirconium, magnesium and aluminum oxides is an important scientific and technological task. In this study, ceramics of the composition x·ZrO2-(90−x)·MgO-10·Al2O3 (x = 10–80 wt.%) were obtained using standard ceramic technology. XRD, SEM, Vickers hardness and biaxial flexural strength measurements were performed to determine the effect of concentration x on the phase composition, microstructure and mechanical characteristics of the sintered samples. The results show that with an increase in the starting concentration x in experimental samples, the fraction of the stabilized ZrO2 phase grows, and the grain size decreases. These two factors determine the values of microhardness and biaxial bending strength. Experimental investigation on the ternary oxide ceramics shows that for ceramics sintered at 1500 °C, the microhardness values varied within the range of 815–1300 HV1 and the biaxial bending strength of 110–250 MPa.

Ceramics doi: 10.3390/ceramics8030113

Authors: Pedro Sá Nathália Souza Pedrita Sampaio James Silva Larissa Rolim

Metal–organic frameworks (MOFs) are promising materials for drug delivery due to their structural tunability and high surface area. This work reports on the synthesis of ZIF-8 for the in situ encapsulation of hesperidin, a flavonoid with poor water solubility used in the treatment of circulatory system disorders, as a gastric-targeted drug delivery system (DDS). A 23 full factorial design was used to optimize drug loading, investigating the effects of DMSO concentration, 2-MIm/Zn2+ molar ratio, and final solution volume (water content). The materials were characterized by ATR-FT-IR, TG, XRD, and SEM analyses, confirming successful ZIF-8 synthesis and partial hesperidin encapsulation. Drug release kinetics were evaluated at pH 1.0 and 6.86. The system showed a faster and more pronounced release at pH 1.0, driven by MOF degradation, demonstrating its potential as a gastric-targeted DDS. This study confirms the feasibility of ZIF-8 to improve hesperidin solubility and bioavailability, highlighting a novel strategy for its therapeutic application.

Ceramics doi: 10.3390/ceramics8030112

Authors: Aida Tulegenova Victor Lisitsyn Gulnur Nogaibekova Renata Nemkayeva Aiymkul Markhabayeva

(YxGd3−x)(AlyGa5−y)O12:Ce and (LuxGd3−x)(AlyGa5−y)O12:Ce ceramics were synthesized for the first time by direct exposure of a powerful electron flux to a mixture of the corresponding oxide components. Five-component ceramics were obtained from oxide powders of Y2O3, Lu2O3, Gd2O3, Al2O3, Ga2O3, and Ce2O3 in less than 1 s, without the use of any additional reagents or process stimulants. The average productivity of the synthesis process was approximately 5 g/s. The reaction yield, defined as the mass ratio of the synthesized ceramic to the initial mixture, ranged from 94% to 99%. The synthesized ceramics exhibit photoluminescence when excited by radiation in the 340–450 nm spectral range. The position of the luminescence bands depends on the specific composition, with the emission maxima located within the 525–560 nm range. It is suggested that under high radiation power density, the element exchange rate between the particles of the initial materials is governed by the formation of an ion–electron plasma.

Ceramics doi: 10.3390/ceramics8030111

Authors: Mia Omerašević Miomir Krsmanović Nada Adamović Chang-An Wang Dušan Bučevac

Porous acicular mullite was fabricated at 1300 °C starting from Al2O3 and mixture of SiO2 and MoO3 obtained by previous oxidation of waste MoSi2. It was found that the presence of MoO3 favors formation of acicular (prism-like) mullite grains with sharp edges. The effect of addition of Fe2O3 (4–12 wt.%) on phase composition, compressive strength, thermal conductivity and microstructure was studied. The addition of Fe2O3 improved the compressive strength from approximately 25 MPa in pure mullite to about 76 MPa in samples containing 12 wt.% Fe2O3, while the open porosity decreased from 55.4% to 51.8%. The presence of Fe2O3 caused a decrease in mullite formation temperature owing to the formation of liquid phase and accelerated diffusion. The solubility of iron oxide in mullite lattice was between 8 and 12 wt.% Fe2O3. The incorporated iron ions also promoted the rounding of sharp edges in prismatic mullite grains, leading to a reduced specific surface area of 0.55 m2/g in the sample with 12 wt.% Fe2O3. The thermal conductivity of mullite increased with addition of 12 wt.% Fe2O3 reaching value of 1.17 W/m·K.

Ceramics doi: 10.3390/ceramics8030110

Authors: Said Abidi Mohamed Benchikhi

This study reports the successful synthesis of pure cobalt-substituted calcium molybdate powders (Co-doped CaMoO4) through a co-precipitation method conducted at room temperature, without the use of surfactants or hazardous organic solvents. The formation of solid solutions with x values ranging from 0.00 to 0.08 was confirmed by X-ray diffraction, Rietveld refinement, and Raman spectroscopy analyses. Elemental analysis using energy-dispersive X-ray spectroscopy showed a strong correlation between the experimental and nominal stoichiometries. The synthesized molybdate powders consist of micrometer-sized particles exhibiting diverse morphologies, including microspheres, flower-like architectures, and dumbbell-shaped particles. These agglomerates are composed of primary particles smaller than 43 nm. The specific surface area increased from 3.59 m2/g for the undoped CaMoO4 to 10.74 m2/g for the 6% Co-doped CaMoO4. These nanostructured powders represent promising host materials for 4f ions, making them potential candidates for solid-state lighting applications.

Ceramics doi: 10.3390/ceramics8030109

Authors: Elena Battiston Francesco Carollo Giulia Tameni Enrico Bernardo Anna Mazzi

To mitigate the issue of accumulating glass waste, an advanced process has been developed for the production of glass foams via alkaline activation, employing industrial glass cullet as the primary raw material. This method contributes to circular economy strategies by enabling high-value upcycling of secondary raw materials. The aim of the study is to conduct an environmental assessment of this recycling process using the Life Cycle Assessment (LCA). The analysis is performed with SimaPro software, adopting the ReCiPe impact assessment method, which allows for the quantification of 18 impact categories. Four distinct foaming processes were compared to determine the most environmentally preferable option and a sensitivity analysis was conducted to assess how variations in energy sources influence the environmental performance. The findings indicate that the scenario involving hardening at 40 °C for seven days results in the highest environmental burdens. Specifically, in the Human Carcinogenic Toxicity category, the normalized impacts for this process are approximately an order of magnitude greater. Electricity consumption is identified as the primary contributor to the overall impact. The sensitivity analysis underscores that utilizing photovoltaic panels reduces impacts. Future developments will focus on expanding the system boundaries to provide a more comprehensive understanding and supporting informed decision-making.

Ceramics doi: 10.3390/ceramics8030108

Authors: Giulia Tameni Enrico Bernardo

The recycling of glass presently poses several challenges, predominantly to the heterogeneous chemical compositions of various glass types, along with the waste glass particle size distribution, both of which critically influence the efficiency and feasibility of recycling operations. Numerous studies have elucidated the potential of converting non-recyclable glass waste into valuable materials thanks to the up-cycling strategies, including stoneware, glass wool fibres, glass foams, glass-ceramics, and geopolymers. Among the promising alternatives for improving waste valorisation of glass, alkali-activated materials (AAMs) emerge as a solution. Waste glasses can be employed both as aggregates and as precursors, with a focus on its application as the sole raw material for synthesis. This overview systematically explores the optimisation of precursor selection from a sustainability standpoint, specifically addressing the mild alkali activation process (<3 mol/L) of waste glasses. The molecular mechanisms governing the hardening process associated with this emerging class of materials are elucidated. Formulating sustainable approaches for the valorisation of glass waste is becoming increasingly critical in response to the rising quantities of non-recyclable glass and growing priority on circular economy principles. In addition, the paper highlights the innovative prospects of alkali-activated materials derived from waste glass, emphasising their emerging roles beyond conventional structural applications. Environmentally relevant applications for alkali-activated materials are reported, including the adsorption of dyes and heavy metals, immobilisation of nuclear waste, and an innovative technique for hardening as microwave-assisted processing.

Ceramics doi: 10.3390/ceramics8030107

Authors: Alex Ellery

Settlement on the Moon will require full exploitation of its resources if such settlements are to be permanent. Such in situ resource utilisation (ISRU) has primarily been focused on accessing water ice at the lunar poles and the use of raw lunar regolith as a compressive building material. Some work has also examined the extraction of metals, but there has been little consideration of the many useful ceramics that can be extracted from the Moon and how they may be fabricated. We introduce a strategy for full lunar industrialisation based on a circular lunar industrial ecology and examine the contribution of ceramics. We review ceramic fabrication methods but focus primarily on 3D printing approaches. The popular direct ink writing method is less suitable for the Moon and other methods require polymers which are scarce on the Moon. This turns out to be crucial, suggesting that full industrialisation of the Moon cannot be completed until the problem of ceramic fabrication is resolved, most likely in conjunction with polymer synthesis from potential carbon sources.

Ceramics doi: 10.3390/ceramics8030106

Authors: P. Casariego V. Sarrablo R. Barrientos S. Santamaria-Fernandez

Recent advances in prefabricated construction have enabled modular systems offering structural performance, rapid assembly, and design flexibility. Textile Ceramic Technology (TCT) integrates ceramic elements within a stainless-steel mesh, creating versatile architectural envelopes for façades, roofs, and pavements. This study investigates the integration of silicon photovoltaic (PV) modules into TCT to develop an industrialized Building-Integrated Photovoltaics (BIPV) system that maintains energy efficiency and visual coherence. Three full-scale solar brick prototypes are presented, detailing design objectives, experimental results, and conclusions. The first prototype demonstrated the feasibility of scaling small silicon PV units with good efficiency but limited aesthetic integration. The second embedded PV cells within ceramic bricks, improving aesthetics while maintaining electrical performance. Durability tests—including humidity, temperature cycling, wind, and hail impact—confirmed system stability, though structural reinforcement is needed for impact resistance. The third prototype outlines future work focusing on modularity and industrial scalability. Results confirm the technical viability of silicon PV integration in TCT, enabling active façades that generate renewable energy without compromising architectural freedom or aesthetics. This research advances industrialized, sustainable building envelopes that reduce environmental impact through distributed energy generation.