Search Results (197)

Transparent ceramics offer a uniquely accessible platform for examining Kerr-type optical phenomena through the lens of molecular structure and local electronic interactions. This review highlights both the magneto-optical (MOKE) and electro-optic (EOKE) forms of the Kerr effect and relates them to the accompanying Faraday and Cotton–Mouton responses. We briefly outline material classes exhibiting Kerr activity—from classic spinels and garnets to perovskites and modern composite ceramics. Particular attention is given to the molecular and atomic mechanisms underlying Kerr behavior—crystal symmetry, site-specific ionic coordination, covalency, electronic-level splitting, carrier localization, vacancy chemistry, and the influence of dopants on polarizability and nonlinear susceptibility. We also summarize advances in experimental setups that have improved measurement precision and spectral range. Selected examples demonstrate how molecular-scale control over electronic structure enables diverse and tunable Kerr responses in different ceramics. We conclude by identifying key remaining challenges in materials design and measurement techniques, and by pointing to future directions driven by improved synthesis and molecular-level engineering. Full article

Lead-free transparent ferroelectric ceramics with integrated opto-electro-mechanical functionalities are pivotal for next-generation multifunctional devices. In this study, K_0.48Na_0.52NbO₃-xLa₂O₃ (KNN-xLa, x = 0.005 − 0.04) ceramics were fabricated via a conventional solid-state route to investigate the La³⁺-induced multiscale structural evolution and its modulation of optical and electrical properties. La³⁺ substitution drives a critical structural transition from an anisotropic orthorhombic phase (Amm2) to a high-symmetry pseudocubic-like tetragonal phase (P4mm) for x ≥ 0.025, characterized by minimal lattice distortion (c/a = 1.0052). This enhanced structural isotropy, coupled with submicron grain refinement (<1 μm) driven by ${\mathrm{V}}_{\mathrm{A}}^{\prime }$-mediated solute drag, effectively suppresses light scattering. Consequently, a high-transparency plateau (T₇₈₀ ≈ 53–58%, T₁₇₀₀ ≈ 70–72%) is achieved for 0.025 ≤ x ≤ 0.035. Simultaneously, the system undergoes a crossover from normal ferroelectric (FE) to relaxor (RF) state, governed by an FE–RF boundary at x = 0.015. While x = 0.005 exhibits robust piezoelectricity (d₃₃ ≈ 92 pC/N), the x = 0.015 composition facilitates a transitional polar state with large strain (0.179%) and high polarization (P_m ≈ 33.3 μC/cm², P_r ≈ 15.8 μC/cm²). Piezoresponse force microscopy (PFM) confirms the domain evolution from lamellar macro-domains to speckle-like polar nanoregions (PNRs), elucidating the intrinsic trade-off between optical transparency and piezoelectricity. This work underscores La³⁺ as a potent structural modifier for tailoring phase boundaries and defect chemistry, providing a cost-effective framework for developing high-performance transparent electromechanical materials. Full article

With the continuous increase in energy density of lithium-ion batteries, thermal safety has become a critical constraint on their further development. To address the limitations of mechanical brittleness and high-temperature infrared transparency in SiO₂ aerogels for thermal safety applications in lithium-ion batteries, this study developed a novel nanofiber aerogel composite by incorporating chitosan and MXene into a SiO₂ aerogel matrix. This material retains the characteristics of being ultra-lightweight and highly elastic while significantly enhancing mechanical strength and high-temperature insulation performance. It exhibits a thermal conductivity of 0.034 W/m K at room temperature and 0.053 W/m K at 400 °C, alongside a compressive strength of 1.172 MPa. In battery thermal runaway propagation tests, the aerogel successfully prevented propagation in serially connected and electrically isolated systems, and delayed thermal runaway propagation by 35 s in a parallel system, demonstrating excellent thermal runaway suppression capability. This work provides an effective material solution for the practical application of high-performance thermal insulation aerogels in battery safety protection and offers inspiration for developing new insulating ceramic aerogels. Full article

Spinel-based glass-ceramics face challenges such as a narrow crystallization window for the target phase and the difficulty in suppressing the competitive Li_xAl_xSi_1−xO₂ crystals. This study proposes a method to regulate the phase formation in ZnO-MgO-Al₂O₃-SiO₂ glass by precisely controlling the heat treatment temperature. The microstructural evolution was analyzed by DSC, XRD, Raman spectroscopy, SEM, TEM, and XPS. The results indicate that the heat treatment at a nucleation temperature of 780 °C for 2 h and a crystallization temperature of 880 °C for 2 h effectively inhibits the precipitation of the Li_xAl_xSi_1−xO₂ secondary phase, yielding a glass-ceramic with nano-sized MgAl₂O₄, ZnAl₂O₄ spinel as the primary crystalline phase. The obtained glass-ceramic exhibits excellent mechanical properties, including a Vickers hardness of 922.6 HV, a flexural strength of 384 MPa, and an elastic modulus of 113 GPa, while maintaining a high visible light transmittance of 84.3%. This work provides a clear processing window and theoretical basis for fabricating high-performance, highly transparent spinel-based glass-ceramics through tailored heat treatment. Full article

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. Full article

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. Full article

Recent developments in sixth-generation (6G) communication systems have increased interest in using sub-terahertz frequencies, particularly the W-band (75–110 GHz), for high-capacity indoor links. At these frequencies, electromagnetic (EM) wave attenuation introduced by building materials becomes a key factor limiting system performance. The objective of this study is to provide continuous, laboratory-validated attenuation characteristics of commonly used construction and finishing materials across the full W-band. Measurements were conducted in an accredited electromagnetic compatibility laboratory using a calibrated far-field setup with a vector network analyzer, W-band frequency extenders, and standard-gain horn antennas inside an anechoic chamber. For each frequency point, 20 measurements were recorded under controlled environmental conditions. The results show distinct attenuation behaviour depending on material type: wood-based materials exhibit 6–13 dB/cm, construction materials 2–4 dB/cm, and insulation materials below 0.3 dB/cm, while ceramic materials exceed 15–23 dB/cm. A general increase in attenuation with frequency is observed, particularly for materials with higher dielectric losses. The presented dataset enables more accurate indoor propagation modelling, supports ray-tracing and link-budget analyses, and provides practical guidelines for designing radio-transparent building components for future 6G communication systems. Full article

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. Full article

Enhancing the mechanical strength of transparent glass-ceramics (TGCs) without compromising their optical performance remains a key challenge for advanced optical and photonic materials. Among aluminosilicate systems, ZnO–MgO–Al₂O₃–SiO₂ (ZMAS) glasses are particularly attractive due to their ability to form ZnAl₂O₄-based nanostructures; however, their ion-exchange (IE) strengthening has not been systematically explored due to the absence of single-charged cations in their composition. In this study, a sodium-modified ZMAS glass was developed to enable efficient chemical strengthening while preserving glass-forming ability and optical clarity. Controlled two-stage heat treatment produced TGCs containing 5 mol% Na₂O, composed solely of ZnAl₂O₄ (gahnite) nanocrystals with an average size of 4–5 nm. The obtained TGCs showed a Vickers hardness of ~8.5 GPa, increasing to ~10–10.5 GPa after ion exchange in molten KNO₃ at 450 °C, without changes in phase composition or optical transmittance. Compared with literature data on alkali-containing TGCs, the developed material demonstrates a higher hardness level while maintaining full transparency. The results reveal a practical route toward chemically strengthened ZnAl₂O₄-based glass-ceramics combining optical clarity, high hardness, and damage tolerance for optical, photonic, and protective applications. Full article

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. Full article

Cr content χ of 0.4 at% for a Cr doped Nd (1 at%): YAG laser rod (LR) gave a higher laser output (I_output) than that of 0.0, 0.7, and 1.0 at% in a specially designed compact solar-pumped laser (SPL) outdoors. I_outputs were measured as a function of an 808 nm pumping laser’s power indoors, changing the transmittance of the output coupler. From the obtained slope efficiencies, round-trip resonator losses Ls for the four χs were estimated, and the best-fit function L(χ) was derived. From the experimentally estimated Cr-to-Nd effective energy transfer efficiency η_Cr→Nd at the four χs, the best-fit function η_Cr→Nd(χ) was derived. Using L(χ), η_Cr→Nd(χ), and a wavelength λ- and χ-dependent absorption coefficient α(λ, χ), inferred from the literature, the power conversion efficiency η_power(χ) under 1 Sun was estimated. The estimated η_power(0.4) and η_power(0.7) were reproduced in experimentally deduced factors at the mode-matching efficiency η_mode = 0.19. The estimated maximum η_power(χ) appeared around χ = 0.2 at%, being 20% higher than that at χ = 0.4 at%. In addition to this, a composite LR (Cr, Nd: YAG core/Gd: YAG cladding) was found to achieve η_mode = 0.68 and η_power = 0.064, ranking among the highest-class SPL η_powers. Full article

Smart manufacturing demands adaptive, scalable, and human-centric solutions for predictive maintenance. This paper introduces the concept of Agentic AI, a paradigm that extends beyond traditional multi-agent systems and collaborative AI by emphasizing agency: the ability of AI entities to act autonomously, coordinate proactively, and remain accountable under human oversight. Through federated learning, edge computing, and distributed intelligence, the proposed framework enables intentional, goal-oriented monitoring agents to form self-organizing predictive maintenance ecosystems. Validated in a ceramic manufacturing facility, the system achieved 94% predictive accuracy, a 67% reduction in false positives, and a 43% decrease in unplanned downtime. Economic analysis confirmed financial viability with a 1.6-year payback period and a €447,300 NPV over five years. The framework also embeds explainable AI and trust calibration mechanisms, ensuring transparency and safe human–machine collaboration. These results demonstrate that Agentic AI provides both conceptual and practical pathways for transitioning from reactive monitoring to resilient, autonomous, and human-centered industrial intelligence. Full article

This study investigates how AI-driven innovations are reshaping manufacturing value chains through the transition from Industry 4.0 to Industry 6.0, particularly in resource-intensive sectors such as ceramics. Addressing a gap in the literature, the research situates the evolution of manufacturing within the broader context of digital transformation, sustainability, and regulatory demands. A mixed-methods approach was employed, combining semi-structured interviews with key industry stakeholders and an extensive review of secondary data, to develop an Industry 6.0 model tailored to the ceramics industry. The findings demonstrate that artificial intelligence, digital twins, and cognitive automation significantly enhance predictive maintenance, real-time supply chain optimization, and regulatory compliance, notably with the Corporate Sustainability Reporting Directive (CSRD). These technological advancements also facilitate circular economy practices and cognitive logistics, thereby fostering greater transparency and sustainability in B2B manufacturing networks. The study concludes that integrating AI-driven automation and cognitive logistics into digital ecosystems and supply chain management serves as a strategic enabler of operational resilience, regulatory alignment, and long-term competitiveness. While the industry-specific focus may limit generalizability, the study underscores the need for further research in diverse manufacturing sectors and longitudinal analyses to fully assess the long-term impact of AI-enabled Industry 6.0 frameworks. Full article

Industrial solid waste fly ash has been widely applied in various fields as a resource for waste repurposing. The use of fly ash can significantly reduce production costs and at the same time reduce environmental pollution to achieve sustainability. This study explores the feasibility of using fly ash as a raw material to formulate high-temperature ceramic glazes, examining the composition, surface phases, and texture patterns of the resultant glazes. This study systematically assesses the impact of formulation modifications on glazing qualities by XRF, XRD, and SEM testing methods. The results show that 1. in high-temperature glazes, the element that determines the degree of transparency in the surface phase is the Ti content; 2. Zinc and Ferrum are important factors that can fine-tune the color shade and crystal mention; and 3. controlling the fly ash content in the glaze can change its color and texture. The novelty of this paper lies in utilizing fly ash to create high-performance, high-value-added ceramic products that feature unique aesthetics and artistic effects. In the future, we can investigate the influence of fly ash on glaze coloration, and the formation of different texture effects, as well as achieve specific color mixing. Full article

The precursor-derived ceramic route is recognized as an advanced and efficient technique for fabricating ceramic matrix composites, particularly suitable for the development and microstructural tailoring of continuous fiber-reinforced ceramic matrix composites. In this work, octamethylcyclotetrasiloxane and tetravinylcyclotetrasiloxane were employed as monomers to synthesize a branched siloxane via ring-opening polymerization. A subsequent hydrosilylation reaction led to the formation of polyvinylsiloxane with a three-dimensional crosslinked structure. The precursor exhibited excellent fluidity, adjustable viscosity, and superior thermosetting characteristics, enabling efficient impregnation and densification of reinforcements through the polymer infiltration and pyrolysis process. Upon pyrolysis, the polyvinylsiloxane gradually converted from an organic polymer to an amorphous inorganic ceramic phase, yielding silicon oxycarbide ceramics with a high ceramic yield of 81.3%. Elemental analysis indicated that the resulting ceramic mainly comprised silicon and oxygen, with a low carbon content. Furthermore, the material demonstrated a stable dielectric constant (~2.5) and low dielectric loss (<0.01), which are beneficial for enhanced thermal stability and dielectric performance. These findings offer a promising precursor system and process reference for the low-cost production of high-performance, multifunctional ceramic matrix composites with strong potential for engineering applications. Full article