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The small‐signal dielectric and piezoelectric coefficients of paper‐derived sodium potassium niobate, K0.5Na0.5NbO3 (KNN), were compared with those of conventionally prepared samples. Results show similar functional properties of paper‐derived KNN without significantly decreasing the small‐signal piezoelectric coefficient. The structure and microstructure analysis of conventional KNN and paper‐derived KNN did not reveal any significant difference in the crystal structure and grain size. However, the temperature‐dependent inter‐ferroelectric phase transition temperature estimated from the temperature‐dependent dielectric permittivity data revealed a decrease of approximately 18°C for the paper‐derived KNN and is possibly associated with the structural and microstructural defects. This work indicates that optimizing suspension chemistry and sintering conditions will be critical to enhance the functional response of paper‐derived KNN further. Moreover, paper‐derived ceramic processing, a novel and cost‐effective additive manufacturing technology, can be potentially used to fabricate other electroceramics with a wide range of porosities and sizes as well as complex geometries and multilayer structures. [ABSTRACT FROM AUTHOR]

SiFeO(N,C)‐based ceramic papers were prepared via a one‐pot synthesis approach by dip‐coating a cellulose‐based paper template with a polymeric perhydropolysilazane precursor modified with iron(III)acetylacetonate. The preceramic composites were subsequently pyrolyzed in ammonia atmosphere at 500, 700, and 1000°C, respectively, and the characteristics of the three resulting ceramic papers were comparatively investigated. Scanning electron microscopy revealed that in each sample, the morphology of the template is successfully transferred on the ceramic system, with the cellulose‐derived fibers being converted to elemental carbon encased by a SiFeO(N,C) coating. Electron transparent cross‐sectional samples for transmission electron microscopy (TEM) were prepared from the ceramic papers, employing a standard ultramicrotomy slice cutting procedure, allowing for a detailed characterization of their in situ generated micro‐/nanostructure as well as occurring crystalline phases. TEM imaging and diffraction revealed that depending on pyrolysis temperature a different microstructure with a distinct phase assemblage is generated in the polymer‐derived ceramic papers. Crystallization from the polymer precursor starts with the precipitation of wüstite (Fe(1‐x)O) nanoparticles at 700°C inside the ceramic coating and secondary ε‐FexN at the fiber‐coating interface. Upon pyrolysis at 1000°C however, the sample primarily accommodates metallic α‐iron nanocrystals that impart ferromagnetic characteristics to the ceramic paper. The results show that the template‐assisted polymer‐derived ceramic route is a feasible approach in the production of complex ceramic compounds with fibrous paper‐like morphology. By adjusting the pyrolysis temperature, microstructure and phase composition of the ceramic paper can be conveniently tailored to the needs of its respective application. [ABSTRACT FROM AUTHOR]

A novel class of preceramic paper may serve as a preform to manufacture lightweight as well as multilayer ceramic products. In this article, we discuss the formation, microstructure, and properties of preceramic papers and their conversion into ceramic materials. Oxide as well nonoxide ceramics were processed into single-sheet, corrugated structures, and multilayer ceramics. A high filler loading and uniform distribution of ceramic fillers involves control of colloidal surface interaction including electrostatic, electrosteric, and mechanical retention. Sintering of an oxide-loaded preceramic paper in air results in highly porous products, with the porosity shape and distribution templated by the pulp fiber used in papermaking. In the case of carbide-loaded paper, dense composite materials are obtained by reactive infiltration processing. Anisotropic properties of machine-fabricated preceramic paper and bonding interfaces in multilayer stacks give rise to anisotropic mechanical properties of the resulting ceramic composites. Noncatastrophic failure was observed when tensile loading stress was applied parallel to the interfaces (in-plane loading). Applying well-established paper processing technologies, including laminated object manufacturing, ceramic structures of complex shape and size can easily be processed, offering a high potential for economical manufacturing. [ABSTRACT FROM AUTHOR]

Novel polycrystalline TiN coated ZnO core‐shell heterostructure nanorods have been prepared on carbon paper substrate via a low‐temperature hydrothermal and sputtering process. The core‐shell emitters exhibit a highly efficient field‐emission performance with a low threshold of electric field ∼0.72 V/μm, and a high emission current density ~16.41 mA/cm2, a level that is the highest of ZnO emitters reported to date. The improved field‐emission characteristics may be attributed to the unique materials combination of ZnO core and TiN shell, resulting in the conductivity enhancement, emission sites increase, and the work function reduction. Our results demonstrate that ZnO/TiN core‐shell emitter will be a distinguished candidate for electronic source devices. [ABSTRACT FROM AUTHOR]

Nanocrystalline mullite has been synthesized by sintering of absorbed monophasic aluminosilicate precursors into cotton wool and filter paper cellulosic structures. Effects of molybdenum and tungsten doping on template mediated mullite at 1200°C and 1400°C have been investigated using differential thermal analysis ( DTA), X-ray diffraction analysis ( XRD), Fourier transform infrared spectroscopy ( FTIR) and field emission scanning electron micrographs ( FESEM). Microstructures of the sintered samples revealed successful replication of cellulosic structure with the formation of dense mullite phases having grain diameter in the range of 50-80 nm. Strong photoluminescence emissions in the UV and visible regions result from the oxygen vacancies and Al-O bonds present in mullite structures. [ABSTRACT FROM AUTHOR]

A biomorphic α-MoO3 ceramic was successfully derived from paper templates. By the infiltration of a Mo-contained solution into paper templates, followed by calcinations at 500°C in air, the cellulose fibers of paper were converted into branches composing of orthorhombic α-MoO3 crystals with grain size ranging from 0.5 to 2 μm. In the final product, the initial fibrous structure of the paper templates was retained. This simple biotemplate method provides a cost-effective and ecofriendly route to obtain advanced self-assembling biomorphic ceramics. [ABSTRACT FROM AUTHOR]

Cationic additives are generally used in coated inkjet printing paper to improve water fastness. This study develops a coating for photographic inkjet printing paper that achieves good water fastness without cationic additives. Porous χ- Al2 O3 flake powder, which has high porosity, high specific surface area, and positive surface charges, is used as a pigment in the coating. The water fastness of prints is evaluated using an immersion method combined with the measurement of light absorbance of the water used for immersion. The results indicate that water fastness can be improved by introducing χ- Al2 O3 powder into the coating pigments. The intrinsic crevices and pores of χ- Al2 O3 provide concave sites for dye colorants and enhance the sorbtion of liquid phase of inks, but stick the dye colorants on the pigment surface. Furthermore, the positive surface charge of χ- Al2 O3 provides cationic sites for the fixation of dye on the coating surface via electrostatic interactions. [ABSTRACT FROM AUTHOR]

This research study shows for the first time the hydration reaction of Activated Art Paper Sludge (AAPS)-lime mixtures cured at 20°C. Two mixtures series were prepared using weight ratios of 3:1 and 1:1 for AAPS/lime. The kinetics of the hydration reaction was investigated by characterization techniques such as X-ray diffraction, thermo-gravimetrical and differential thermal analysis, 27Al and 29Si {1H} magic angle spinning nuclear magnetic resonance. Results show higher quantity of hydrated phases formed with the increase of the AAPS/lime ratio (such as calcium silicates hydrates (C–S–H), hydrated tetracalcium monocarboaluminate , and hydrotalcite-like phases), specially C–S–H exhibiting a major incorporation of Al3+ into silicate chains, increasing its medium chain length. It becomes demonstrated that mechanical performance of the studied mixtures will be directly influenced by all these parameters. [ABSTRACT FROM AUTHOR]

In this paper, two new ternary layered MAX phase ceramics, Sc2GaC and Sc2InC, were successfully synthesized by spark plasma sintering. The crystal structures of two new compounds were determined by X‐ray diffraction. The lattice parameters were a = 3.3609(0) Å and c = 14.5849(9) Å for Sc2GaC, and a = 3.3453(6) Å and c = 15.2236(3) Å for Sc2InC, wherein the Sc atoms were located at (1/3, 2/3, 0.07330[Ga]/0.08268[In]), the A atoms were located at (1/3, 2/3, 3/4), and the C atoms were located at (0, 0, 0). Scanning electron microscopy images of two new MAX phase ceramics were also given in this paper, showing obvious layered characteristics. [ABSTRACT FROM AUTHOR]

[Ca24Al24.08Zr3.92O64]4+(4e−) electrides are ceramic materials with low work functions that can store high‐density free electrons. So, it has great application potential in electron emission. In this paper, The mixed powders of CaO, Al2O3, ZrO2, and Al in a certain stoichiometric ratio were used as precursors, and [Ca24Al24.08Zr3.92O64]4+(4e−) blocks were fabricated through in‐situ reduction. The synthetic block samples have fewer pores, cracks, and impurities, and the blocks' relative density reaches 99.6%. At the same time, the blocks' cages were injected with high‐density electrons during the sintering, and the electron density reached 2 × 1021 cm−3. This makes the sample realize the transition from insulation to conductor. In addition, the block's emission current and effective work function is 1.75 A/cm2 and 2.25 eV, respectively, at 1100°C. The research in this paper provides a new way for the low‐cost and industrial production of high‐quality [Ca24Al24.08Zr3.92O64]4+(4e−). [ABSTRACT FROM AUTHOR]

This paper investigates the phase evolution and pulverization mechanism of a self‐pulverizing carbonatable clinker (SPCC) with a variety of raw material compositions. The particle size, mineral phases, and microstructure of SPCC, produced by sintering at 1400°C for 3 h, were systematically studied by laser particle size testing, XRD/QXRD and SEM/EDS. Results show that clinkers sintered by raw materials with low‐Ca/low‐Al (Ca/Si < 1.6; Al2O3 < 10 wt.%) or high‐Ca/medium‐Al (Ca/Si > 2.6; Al2O3 ≈ 10 wt.%) are non‐pulverized after cooling. The mineral phases of C2AS, CA, and C12A7 are considered to facilitate clinker pulverization at low γ‐C2S contents. With the increase of Al2O3 content in raw materials, SPCC is refined in particle size, accompanied by the significant decrease in the content of calcium silicates. Based on the results, guidelines for producing SPCC are proposed. [ABSTRACT FROM AUTHOR]

B Cover Photograph b : Atomic force microscopy topographies and scanning electron microscopy (inserts) images depict the rationally designed interfaces to mitigate the photogenerated charge losses in the hematite photoanode. B Image Credit b : Images are partially modified from the paper Bedin, K.C., Rodríguez-Gutiérrez, I., Peregrino, L.R.P., Vayssieres, L. and Souza, F. L. Souza. On electron loss lowering at hematite photoelectrode interfaces. [Extracted from the article]

A novel hybrid compressive mica seal was developed that showed an exceptionally low leak rate of ∼8.9 × 10[sup -4] sccm/cm (standard cubic centimeters per minute per unit leak length of seal) at 800°C and a compressive stress of 100 psi, about 740 times lower than that of the conventional compressive mica seals (6.6 × 10[sup -1] sccm/cm), at a pressure gradient of 2 psi. The hybrid compressive mica seals were composed of two compliant metallic layers and a mica layer. Three commercially available micas were tested in this study. All showed substantial improvements in reducing the leak rates by using the hybrid design. The best results were obtained using muscovite single-crystal mica and 125 µm silver layers. Using the paper form of muscovite and phlogopite mica, the leak rates were still far superior (∼1 × 10[sup -1] sccm/cm) compared with mica without the compliant silver layer (about 6-9 sccm/cm). The microstructure of the mica was examined before and after the 800°C leak tests. These results are compared with results for hybrid seals using glass interlayers. In addition, an explanation for the substantial reduction of the leak rates is proposed, and the application of the hybrid compressive mica seals in planar SOFC stacks is briefly addressed. [ABSTRACT FROM AUTHOR]

Here, we provide the correct glass transition temperatures for 10°C/min cooling/heating rate-treated samples. Corrigendum to "A tetrad effect in the glass transition of lanthanide-doped sodium disilicate glasses" (J. Am. Ceram. In our paper "A tetrad effect in the glass transition of lanthanide-doped sodium disilicate glasses", rather than plotting values for the glass transition (T SB g sb ) for a matched cooling/heating rate of 10°C/min (as stated in that paper), we erroneously plotted values for the glass transition (T SB g sb ) of first calorimetric runs on glasses "as synthesized" with unknown thermal history (i.e., cooling rate). [Extracted from the article]

Phosphors doped with Mn4+ ions have strong emission in the red and far‐red light regions and are therefore used as red phosphors for indoor plant cultivation light‐emitting diodes (LEDs) and white LEDs (w‐LEDs). This paper introduces La2Mg(Mg1/3Ta2/3)O6: Mn4+ (Mg2La3TaO9: Mn4+) red phosphors prepared by conventional high‐temperature solid‐phase method. The broad excitation band of Mg2La3TaO9: Mn4+ phosphor is effectively excited by ultraviolet and blue light in the range of 250–600 nm, with the emission of 707 nm centered on far‐red light. The phosphor has a high color purity of 99.07% and an internal quantum efficiency of 59.87%. To further enhance the performance of the phosphor, a cation substitution method was adopted in this paper to synthesize La2Mg(Al1/2Ta1/2)O6: Mn4+ phosphor by replacing [1/3Mg2+–2/3Ta5+] in La2Mg(Mg1/3Ta2/3)O6: Mn4+ with [1/2Al3+–1/2Ta5+]. The luminescence intensity and thermal stability of the samples were enhanced. The emission spectrum of the Mg2La3TaO9: Mn4+ samples matched well with the phytochrome PFR (phytochrome that absorbs far‐red light) and is suitable for the preparation of LEDs for indoor plant cultivation. The concentration quenching effect of the samples was investigated, the main mechanism of which is the electric dipole–dipole interaction. Red LEDs and w‐LEDs devices were prepared with the synthesized phosphors that produce light stably at different currents. The w‐LEDs have a correlated color temperature of 5310 K and a color rendering index of 80.1. Therefore, these samples are expected to be used as red components for w‐LEDs. [ABSTRACT FROM AUTHOR]

This paper describes research on clay wastes (CWs) produced in the paper manufacture process. Once activated under controlled thermal conditions, CW is transformed into calcined clay products providing added value as supplementary cementing materials. The obtention of a pozzolanic material (metakaolin (MK)) from valorized CW constitutes an alternative source of pozzolans for the elaboration of blended Portland cements, as well as a priority research line from the environmental point of view. This research work presents the properties of calcined CW (chemical, mineralogical, and pozzolanic) and its influence on Portland cements containing 10% calcined clay product. The results obtained with different characterization techniques (XRF, DTA, XRD, SEM-EDX) showed that the thermally activated CW exhibits acceptable properties to be used as supplementary cementing materials in the manufacture of commercial Portland cements. The derived MK can react with calcium hydroxide, from cement hydration, producing hydrated phases with hydraulic properties (calcium silicate hydrate gels, tobermorite, C4AH13, zeolite). These novel blended cements comply with the chemical, physical, and mechanical specifications established in the existing standards. [ABSTRACT FROM AUTHOR]

Engineering the optical bandgaps of classic ferroelectrics from the typical ultraviolet range down to the visible range is an emerging methodology of developing the next‐generation optoelectric and opto‐ferroelectric devices including ferroelectric solar cells, light‐driven transistors and modulators, and multi‐sensors/energy harvesters. Recently, a material interface comprised of a pseudo‐morphotropic phase boundary between the tungsten bronze and perovskite phases of the KNBNNO [(K,Na,Ba)x(Ni,Nb)yOz] has been reported to be an effective approach for bandgap engineering while retaining excellent ferroelectricity and piezoelectricity of the perovskite‐phased KNBNNO. However, this approach requires the compositions of the materials to be determined at the synthesis stage, leaving little room for any further modification of the microstructure and functional properties at the post‐processing stage. This paper presents a post‐processing method, that is, atmospheric annealing in N2 and O2, to grow the necessary tungsten bronze phase out of the perovskite phase in the KNBNNO. This method is advantageous over the previously reported because it enables to grow the tungsten bronze–perovskite interface region independent of the initial composition. The distinctive electrical properties and the giant tunability of photoconductivity of the tungsten bronze phase, the perovskite phase, and the interface are characterized in detail in this paper, supporting the exploitation of fabricating opto‐ferroelectric devices using the reported method which is compatible and comparable with some of the post‐processing methods applied in the silicon industry. [ABSTRACT FROM AUTHOR]

The penetration of copper‐smelting slag into refractories is a major challenge to the research of chromium‐free refractories for copper‐smelting furnace. In this paper, Y2O3 was added to regulate the pore structure of periclase refractories, which enhanced their various properties, especially corrosion resistance to copper converter slag. The results showed that the periclase refractories doped with 1.0 wt.% Y2O3 (1Y sample) possessed the optimum properties. Compared to the sample without Y2O3, the apparent porosity of 1Y sample was decreased by 7.3%, and its average pore diameter was only 3.7 μm. The addition of Y2O3 filled the pores among MgO grains and promoted the expansion of high melting point silicates, thereby reducing the pore size and causing more complex pore structures. This was beneficial to improving the corrosion resistance of periclase to copper slag, especially to prevent the penetration of Cux+ and Na+. After static slag corrosion, the permeability index was significantly decreased by 41% compared to periclase refractories without Y2O3. Moreover, compared to industrial MgO–Cr2O3 refractories, the 1Y sample possessed better resistance to copper slag erosion based on rotating finger tests, and its permeability index and penetration depth decreased by almost 50%. [ABSTRACT FROM AUTHOR]

So far, developed microwave absorbers exhibit significant changes in absorption with temperature, which hinder their operation within a wide temperature range. In this paper, a microwave absorber based on SiBCN ceramics was prepared. Due to the excellent high‐temperature stability of SiBCN ceramics, its permittivity changes less with temperature, avoiding the issue of performance deterioration or even failure that traditional refractory absorbers face at high temperatures. The experiment proves the absorption bandwidth for –15 dB of the SiBCN metamaterials absorber (SMA) is 12 GHz at 800°C, with a maximum absorptivity of 99.99%. According to the computed data, the resonance loss contributes 81.9 to 94.5% of the microwave absorption of SMA. This work demonstrates significant potential for applications in radar stealth under harsh conditions. [ABSTRACT FROM AUTHOR]

Functionally graded ceramics (FGCs), which combine the properties of various composite ceramics, have been widely used in the aerospace, armament, and other industries. One of the newest melt‐growth ceramic additive manufacturing techniques, laser directed energy deposition (LDED), enables the creation of gradient materials by controlling the ratio of powder delivery. Ceramic–ceramic type gradient materials are the subject of fewer studies, and the majority of LDED gradient material systems now in research are metal–metal type and metal–ceramic type gradient materials. In this paper, LDED is used to create TiCp reinforced Al2O3 FGCs with three different transition paths. The results indicate that the longitudinal section of the gradient samples distinctly exhibits characteristics of gradient distribution. Furthermore, as the proportion of TiCp increases, there is a corresponding increase in the proportion of TiCp particles in the samples. The microstructure of Al2O3 transforms from columnar crystals to irregular shapes. Regarding the mechanical properties of the gradient samples, the area containing 30 wt.% of TiCp shows a significant improvement in wear resistance, with a 48.13% increase compared to the Al2O3 region. Additionally, this region demonstrates a 12.62% rise in hardness and a 9.48% increase in fracture toughness. [ABSTRACT FROM AUTHOR]

Recently, there has been a growing demand for broadband near‐infrared (NIR) phosphor. The paper proposes a novel Cr3+ doped Ca2Y3Sb3O14 phosphor through basic research of Ca2Ln3Sb3O14: Cr3+ (Ln = Sc, Lu, and Y) phosphor. Under 467 nm excitation, Ca2Y3Sb3O14: Cr3+ phosphor shows a broad NIR emission band (650–950 nm) centered at 776 nm with a full width at half‐maximum of 110 nm. The optimal Cr3+ doping concentration is 0.05, with an internal quantum efficiency of 78%. Meanwhile, the photoluminescence emission intensity at 373 K remains 61.3% of that at room temperature. Using phosphor‐in‐glass technology, a glass–ceramic plate showed a slight improvement in its thermal stability compared to the pure phosphor. Combining Ca2Y3Sb3O14: 0.05Cr3+ phosphor with a commercial blue‐light‐emitting chip presents an output power of 44.51 mW with a photoelectric conversion efficiency of 14.78% at a drive current of 100 mA. These results suggest that the Ca2Y3Sb3O14: Cr3+ phosphor has great potential in the pc‐light‐emitting diodes. [ABSTRACT FROM AUTHOR]

Dielectric capacitors have been widely studied in advanced electronics systems due to their rapid discharge rate and high-power density. Among them, relaxor ferroelectrics characterized by nanodomains possess broad application prospects as dielectricmaterialswith high energy density and high efficiency. In this paper, the dielectric characteristics, energy storage performance, and charge--discharge behavior of rare-earth Yb-doped Sr0.7Bi0.2TiO3 ceramics are systematically investigated. The Yb-doped SBT ceramics reduced the grain size, improved the insulation and thermal conductivity, and significantly improved the dielectric breakdown strength. Finally, a high recoverable energy density of 2.32 J/cm³ and an excellent energy storage efficiency of 92.2% were obtained at 300 kV/cm. In addition, pulsed charge--discharge tests show that Sr0.7Bi0.15Yb0.05TiO3 possesses a rapid discharge rate and high-power density with superior thermal stability. Based on these outstanding characteristics, Sr0.7Bi0.15Yb0.05TiO3 exhibits promising applications in pulsed power systems. [ABSTRACT FROM AUTHOR]

BaTiO3‐based compounds are recognized as the most common dielectric material used in multilayer ceramic capacitors (MLCCs), among which, BaTiO3‐BiMeO3 is extensively investigated to improve the thermal stability and extend the service life of MLCCs, which are strongly dependent on the conductivity at high temperatures. Despite numerous efforts have been made, the mechanism of oxygen vacancy conduction, which makes the major contributions to the conduction mechanism of BaTiO3‐based compounds at high temperatures below 450°C, is still unclear. In this paper, BaTiO3, 0.88BaTiO3‐0.12Bi(Zn2/3Nb1/3)O3, 0.88BaTiO3‐0.12Bi(Mg2/3Nb1/3)O3, and 0.88BaTiO3‐0.12Bi(Mg2/3Ta1/3)O3 ceramics have been prepared by solid‐state reaction method, and their electrical and dielectric properties have been studied in detail. Meanwhile, first principles were applied to study the mechanisms of the increase of electrical resistivity and the decrease of dielectric loss. It is found that B‐site dopants (Zn, Mg, Nb, and Ta) are effective in reducing the conductivity by inhibiting the migration of oxygen vacancies, which is a kinetics process with an increase of energy barrier. Notably, the greater ability of Zn to inhibit oxygen vacancies migration is a combination of thermodynamics (a strong ability to trap oxygen vacancies) and kinetics (an effect of block the migrating defects in the lattice). This work reveals a new insight into the mechanism of oxygen vacancies migration in BaTiO3‐based perovskite compounds, which makes BaTiO3‐BiMeO3 prospective in designing efficient and durable medium‐temperature solid oxide capacitor devices. [ABSTRACT FROM AUTHOR]

Knowledge of thermodynamics and phase equilibria of oxidic materials is crucial for advancement in the field of ceramics and glass. With the development of computational thermodynamics, predicting phase diagrams and chemical reactions of multicomponent systems has become possible. However, there are still plenty of oxides, the thermodynamic properties of which have not been identified due to the challenges in conducting experiments. Therefore, a key to the advancement in thermodynamic modeling would be to develop a universal model that can be used to estimate the thermodynamic properties of oxides with reliable extrapolation capacity. Atomistic (or molecular) scale models are still insufficient in predicting the thermodynamic properties of oxides at any scale. Alternatively, among group contribution–based methods, the polyhedron model has presented its potential in the estimation of the thermodynamic properties of ionic crystals. However, this model still demands improvements that increase the model's accuracy and extrapolation capacity. In this paper, the background and the state‐of‐the‐art of polyhedron model will be presented together with its strengths and shortcomings. Subsequently, it will be briefly discussed how the field of artificial intelligence could be exploited to devise the next generation of the polyhedron model, the modified polyhedron model. [ABSTRACT FROM AUTHOR]

Ceramic matrix composites (CMCs) and environmental barrier coatings (EBCs) are key technologies that can enable improvements in the thermal and propulsive efficiency of gas turbine engines. However, CMCs and EBCs are susceptible to various life limiting damage modes associated with the engine operating environment such as oxidation, recession, thermomechanical stress/strain, corrosion, foreign object damage (FOD), and solid particle erosion (SPE). Despite its importance, there is a limited understanding of the SPE behavior of CMCs and EBCs in the literature. This paper reviews the status of SPE research for CMCs and EBCs and provides a perspective towards future research. [ABSTRACT FROM AUTHOR]

High‐temperature corrosion resistance is one of the major challenges for hot‐section components in gas turbines. In this paper, the interaction of a novel high entropy (HE) (Y0.2Gd0.2Ho0.2Er0.2Yb0.2)3Al5O12/Al2O3 directionally solidified eutectic (DSE) with molten calcium–magnesium–aluminosilicate (CMAS) at 1500°C for 4 to 200 h was investigated and the results indicate that (Y0.2Gd0.2Ho0.2Er0.2Yb0.2)3Al5O12/Al2O3 DSE possesses excellent CMAS resistance, with a true recession depth about 219.5 μm after corroded by CMAS at 1500°C for 200 h. Moreover, possible explanations on the outstanding CMAS corrosion resistance, including the protective diffusion‐blocking garnet layer and the actively adjustment on the corrosion activity of CMAS melt by both the rapid dissolution of Al2O3 phase and the synergetic effects of multicomponent RE elements, are deduced based on the identification, distribution and evolution analysis of the reaction products over the corrosion time. The current results can cast light on new mechanisms and strategies with respect to multilevel optimization to develop new high‐temperature structural materials with enhanced CMAS corrosion resistance ability. [ABSTRACT FROM AUTHOR]

Glass is a versatile material with a remarkable history and many practical applications. It plays a critical role in our everyday lives, the advancement of science, and the development of many technologies. The Edisonian type trial‐and‐error method was commonly used for conventional design of glass compositions, which was time‐consuming and costly. With the urgent need to develop new glass compositions for technology applications rapidly, it has become necessary to develop precise property models with predictive powers using large databases and efficient formulation approaches. This paper reviews the design of glass compositions using these analytical and numerical models of composition–structure–property relations of glasses, some based on large databases and machine learning approaches. Aspects of data collection, model fitting, feature extraction, model evaluation, and uncertainty quantification will be covered. Furthermore, advances in the glass optimization framework and available tools are summarized with examples. The outlook and perspective for further glass property model development and formulation approaches are discussed. [ABSTRACT FROM AUTHOR]

Ceramic aerogels are attractive for their promising applications in thermal insulation, ultrafiltration, catalysis, and many other areas, owing to their high porosity, low density, high specific surface area, low thermal conductivity, and thermal stability. However, the practical applications of conventional ceramic aerogels are usually impeded by brittleness. Resilient ceramic aerogels overcame the brittleness of conventional ceramic aerogels and realized reversible compressibility, but they usually show brittleness under tensile stress and limited load‐bearing ability. In this short review paper, we reviewed the strategies to modify the mechanical properties of resilient ceramic aerogel. These strategies were achieved through tuning the deformation and moving ability of the nanowire building blocks and the deformation resistance provided by the aerogel architecture. Perspectives for further modifying the mechanical properties of resilient ceramic aerogel are also discussed. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the effect of processing parameters and composite regulation on the structure and property relationship of lightweight low‐permittivity Li2O–Al2O3–B2O3 dielectric system. Li2BAlO4 ceramic and (1 − x)Li2BAlO4–xSrTiO3 ceramics were synthesized using a conventional solid‐state reaction method. Thermodynamic analysis, sintering temperature, phase formation, crystal structure, and microwave dielectric properties were investigated. Thermal analysis revealed a melting temperature of 847°C, suggesting a comparatively low temperature for the sintering of Li2BAlO4 ceramics. Li2BAlO4 crystalized into a monoclinic structure with P21/c space group, with [Al2B2O8] rings connected by [BO3] triangles and [AlO4] tetrahedra through Al–O–Al bridges. Dense Li2BAlO4 ceramics with a relative density of ∼97.7% were sintered at 750°C and had optimal microwave dielectric properties with relative permittivity (εr) of 5.13, quality factor (Q × f) of 22 610 GHz, and the temperature coefficient of resonance frequency (τf) of −112.5 ppm/°C. The 0.88Li2BAlO4–0.12SrTiO3 composite ceramic has excellent microwave dielectric properties with εr = 8.83, Q × f = 14 000 GHz, τf = 4.6 ppm/°C. The ceramics also demonstrated an inert behavior with silver electrodes proving its application in low‐temperature cofired ceramic (LTCC) technology. [ABSTRACT FROM AUTHOR]

Increasing the active site of redox reactions on the surface of photocatalysts and accelerating the separation and transfer of photogenerated electron‐hole pairs are effective methods to improve the hydrogen evolution of composite photocatalysts. Non‐precious metal Ni photo‐deposition is anchored in situ on the ZnIn2S4 surface to generate the cocatalyst Ni(OH)2, which improves the photocatalytic hydrogen evolution performance of the composite sample. Under visible light irradiation, the ZnIn2S4 semiconductor stimulates photon‐generated carriers. Ni2+ acts as the defect center of photogenerated electron‐hole pairs to promote the separation of carriers. It serves as the capture site of light‐generated holes to reduce the carrier recombination rate so that the light‐generated electrons on the ZnIn2S4 surface promote H+ reduction in H2. Ni(OH)2 provides the active site for oxidation reaction on the surface of semiconductor materials, allowing the carrier to be consumed faster and improving the photocatalytic stability of semiconductor materials. The addition of 2 wt% Ni2+ resulted in a hydrogen evolution rate of 10 066 µmol·g−1 ·h−1 for ZnIn2S4/Ni(OH)2, which was 2.5 times higher than that of pure ZnIn2S4. This paper presents a reference case for enhancing the stability of sulfide to promote its photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

The origin of the excellent properties of KTN‐based materials around Curie temperature (TC), which should be originated form the motion of polar nanoregions (PNRs), has attracted considerable research interest. In this paper, the relaxation of a KTa0.63Nb0.37O3 single crystal is discussed with the temperature dependence of permittivity. Moreover, its pyroelectric effect above TC is investigated. In detail, the pyroelectric coefficient decreases from ∼110.0 to ∼13.0 μC/(m2 K), with the temperature increasing from 22 to 33°C, and finally reduces to 0 at 100°C with PNRs disappear. Moreover, the dynamic dielectric nonlinearity for the KTN single crystal is studied in the paraelectric phase. To investigate these mechanisms, the amplitude and phase angle of the first and third harmonics under various electric fields, frequencies, and temperatures are analyzed. As a result, the motions of PNRs induced by electric field, which is pinned and depinned by the defect, are presented to explain the nonlinear dielectric response observed in the paraelectric KTN single crystal. [ABSTRACT FROM AUTHOR]

Silica glass is a superior functional material due to its excellent thermophysical properties. With the increasing demand for large‐size and high‐purity silica glass, a novel chemical vapor deposition (CVD) furnace characterized by a crucible has been proposed, which requires a deep understanding of heat and mass transport characteristics inside for better control. Aimed at this, a comprehensive simulation model is developed in the paper. The model is well verified with the experimentally measured temperature and is then used to examine distributions of temperature and critical components in the furnace. Effects of the injection conditions are further investigated, among which the H2–O2 equivalence ratio and flow rate have a great influence on the temperature and components distributions, whereas the SiCl4 flow rate mainly affects the SiO2 distribution. An improved injection condition is put forward finally, which is much better than the reference case; the average for the temperature and SiO2 concentration on the deposition surface is increased, respectively, by 23 K and 0.018 mol/m3, and sufficient homogeneity is maintained. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) fiber‐reinforced SiC matrix (SiC/SiC) composites have emerged as a new material candidate for fuel claddings in light water reactors. Recent studies showed that the load capacity of SiC/SiC materials exhibits a considerable statistical variation. Therefore, reliability analysis plays a critical role in design of SiC/SiC composite claddings. This paper presents a probabilistic model for the lifetime distribution of SiC/SiC composites. The model is anchored by a multiaxial stress‐based failure criterion and subcritical damage accumulation mechanism. Based on the kinetics of subcritical damage growth, the lifetime distribution of a laboratory test specimen for any given loading history can be calculated. A finite weakest‐link model is used to extrapolate the lifetime distribution of test specimens to full‐length claddings. It is shown that the damage accumulation mechanism has a strong influence on the lifetime distribution of the cladding. This finding highlights the importance of understanding the static fatigue behavior of SiC/SiC composites. The present analysis also demonstrates an intricate length effect on the failure probability of the cladding, which is expected to play a crucial role in design extrapolation. [ABSTRACT FROM AUTHOR]

This paper has studied the densification, microstructure, and properties of polycrystalline La0.6Ce0.3Pr0.1B6–ZrB2 composites prepared by spark plasma sintering (SPS). The highest relative density of 98.7% is obtained at the SPS condition of axial mechanical pressure 50 MPa, sintering temperature 1900°C and holding time 5 min. The Vickers hardness decreases linearly from the maximum value of 21.49 GPa to the value of 8.24 GPa with the tested temperature increased from room temperature to 1000°C. The effects of crack deflection and bridging have resulted in the fracture toughness of 4.56 MPa m1/2 of dense polycrystalline La0.6Ce0.3Pr0.1B6–ZrB2 composite. The J1kV of 7.02 A/cm2 obtained at 1600°C, the work function of 2.743 eV determined by ultraviolet photoelectron spectroscopy, and the good oxidation resistance below 1100°C in air have revealed that the dense polycrystalline La0.6Ce0.3Pr0.1B6–ZrB2 composite has a good potential to be a promising hot cathode material. [ABSTRACT FROM AUTHOR]

Y2/3Cu3Ti4O12 ceramic is a novel semiconductor with potential applications in electronic devices. However, its resistance drift and surface structure defects limit the application for negative temperature coefficient thermistor devices. A comparative study of solid‐phase and a Pechini processing of Y2/3Cu3Ti4O12 is presented in this paper, in the particular comparative study of stability. The Pechini method is found to be effective in lowering sintering temperature and improving thermal stability (ΔR/R0 < 0.3％) in comparison with solid‐phase method. The origin of the stability deterioration is related to the oxidation state of Cu ions and the migration of sublattice. The Pechini method overcomes stoichiometric ratio deviations and cation vacancy diffusion, thus reducing metal ion segregation in a continuous high‐temperature environment and thereby showing unique insensitivity to oxygen. The important role of the Pechini method in improving thermal stability is revealed, which is expected to be used in the preparation of high stability electron devices. [ABSTRACT FROM AUTHOR]