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In this work, stacked SiC fibers paper‐reinforced SiC ceramic matrix composites (SiCnf/SiC CMCs) were prepared by nanoimpregnation and transient eutectic (NITE) process using ultra‐long single‐crystal SiC nanofibers. The effect of the SiCnf surface modification via boron nitride (BN) interphase deposition as well as the sintering additive (Al2O3–Y2O3) content on the density, microstructure, and mechanical properties of SiCnf/SiC CMCs has been investigated systematically. The results revealed that the laminated SiCnf/SiC CMCs feature a significant saw‐tooth‐like curve on the load–displacement test, which indicates that the obtained laminated structure with the weak interlayer binding owning to the BN coating treatment possesses significant toughening to the SiC ceramics. Specifically, the SiCnf/SiC CMCs with the sintering additive content of 12 wt% revealed a fracture toughness of over 10 MPa m1/2 after 60 min of BN interface deposition, which is 104.31% higher than that of the composites prepared without BN coating. [ABSTRACT FROM AUTHOR]

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]

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]

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]

In this paper, X‐ray‐activated super long persistent ultraviolet A luminescence from Ca3(PO4)2: Ce3+ has been observed. The crystal structure analysis has shown that the as‐prepared samples are pure β‐Ca3(PO4)2 phases with rhombohedral structure and R3c space group. The photoluminescent spectra of the samples all consist of a broad band in 340–400 nm UVA1 region, which is assigned to the 5d1–4f1 electronic transition of Ce3+ ions. More important, under the 3 min X‐ray irradiation, Ca3(PO4)2: Ce3+ show super long persistent luminescence in the UVA1 region, which can persist for more than 16 h. And its afterglow intensity after 16 h decay is still 4.10 times stronger of the back ground intensity. Furthermore, only 10 s X‐ray irradiation can induce excellent long persistent UVA luminescence of Ca3(PO4)2: 0.08Ce3+, which can persist for more than 5 h and afterglow emission intensity is about 3.03 times of the background intensity. The trap analysis has confirmed that the different X‐ray irradiation time do not create new traps and there is the same trap with 0.75 eV trap depth existing even under the extremely low X‐ray dose (10 s X‐ray irradiation). Furthermore, under 10 s X‐ray irradiation, the thermoluminescence (TL) intensity of Ca3(PO4)2: 0.08Ce3+ still reaches 0.32 times of the initial TL intensity even after 120 min, which thus leads to the super long persistent luminescence. Thus, the large amounts of trapped electrons induced by the high energy X‐ray irradiation are the principal cause for super long persistent UVA luminescence of Ca3(PO4)2: Ce3+. [ABSTRACT FROM AUTHOR]

As a luminescent center ion in materials for deep red and near‐infrared light, Cr3+ has been extensively studied in octahedral host materials. In this study, using zinc aluminate (ZnAl2O4) and magnesium aluminate (MgAl2O4) spinels with abundant octahedra as substrates, a series of Zn1−xMgxAl2O4:0.5%Cr3+ (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) fluorescent powders were first prepared via a high‐temperature solid‐state method. The influence of different Mg/Zn ratios on (Zn/Mg)Al2O4:0.5%Cr3+ optical properties was thoroughly explored. Experimental results show that an increase in the Mg/Zn ratio reduces the crystal field strength (Dq) and leads to distortion of the [AlO6] octahedra, resulting in broadening of the photoluminescence emission spectrum. Furthermore, the addition of Mg gradually reduces the formation of inverse spinel. An appropriate Mg/Zn ratio can improve luminescent intensity and quantum efficiency. In summary, this paper, through bandgap engineering by adjusting the Mg/Zn ratio, provides a detailed account of the changes in optical properties and the underlying mechanisms during the transition from ZnAl2O4:0.5%Cr3+ to MgAl2O4:0.5%Cr3+ spinels. It offers valuable insights for further research on the practical applications of Cr3+ in areas such as lighting displays and bioimaging. [ABSTRACT FROM AUTHOR]

With the emergence of 5G–6G communication technology, the miniaturization and integration of electronic components are crucial. Ba3Ti4Nb4O21 (BTN) ceramics with hexagonal structures have attracted special attention due to their high dielectric constant, which shows greater application potential in communication base stations and dielectric resonators. However, its high sintering temperature and low‐quality factors also greatly limit the application field. In this paper, boric acid (H3BO3) as a dopant, was used to investigate the influence on the structure, microstructure, Raman spectrum, and microwave properties for Ba2.92Cu0.08(Zn1/3Nb2/3)2Ti2Nb4O21 (BCZTN)‐xHB (0.25≤x≤1.25 wt%) ceramics. The results reflected that H3BO3 was an effective additive, which could promote ceramic densification, accelerate grain growth and uniform distribution, and enhance its microwave performance. Among them, high densification was 93.92 ± 0.35%, and the Q × f value ∼16981 ± 340 GHz at x = 0.75, was more than 2∼3 times higher than other BTN‐based ceramics. Superior microwave dielectric properties were achieved for 0.75 wt% H3BO3‐doped BCZTN ceramic sintered at 900°C: εr∼42.35 ± 0.48, Q×f∼16981 ± 340 GHz, and τf∼40.02 ± 1.43 ppm/°C. More encouragingly, BCZTN‐0.75HB ceramic did not chemically react with Ag, which suggested that it had the potential to be a candidate material for low‐temperature co‐fired ceramics base station communication devices. [ABSTRACT FROM AUTHOR]

In this paper, we examine the cleavage fracture anisotropy in tantalum carbides, namely, TaC, α‐Ta2C, and ζ‐Ta4C3 − x, using density functional theory (DFT) calculations. Our investigation identifies the presence of multiple low‐energy cleavage planes indicating multiple potential pathways for crack propagation in these ceramics, even the low symmetry compounds. The anisotropy characteristics of cleavage fractures exhibited by α‐Ta2C and ζ‐Ta4C3 − x closely align with the intrinsic fracture anisotropy observed in TaC. Notably, there exist at least three pyramidal planes in ζ‐Ta4C3 − x whose cleavage energies are less than those of the carbon‐depleted basal planes, previously reported to have the lowest cleavage energy. The observed preference in experiments for cleavage along carbon‐depleted basal planes, exclusive of other identified low‐energy planes, points to factors beyond cleavage energy influencing cleavage plane preference. [ABSTRACT FROM AUTHOR]

High‐temperature piezoelectric sensing is usually used in the aerospace, automotive, and power plant fields. High temperature piezoelectric ceramics are considered the key materials in these fields. In this paper, Ca1−x(Ba1/2Sr1/2)xBi2Nb1.985(W3/4Mn1/4)0.015O9 (x = 0.05, 0.10, 0.15 and 0.20) (C1−xBSxBNWM) has been synthesized by a traditional solid state reaction method. The effects of substitution of calcium at the A‐site by barium and strontium on phase evolution and piezoelectric properties of the CaBi2Nb2O9 orthorhombic Aurivillius phases were investigated. The crystal structure of piezoelectric ceramics was characterized by XRD, Rietveld refinement, and Raman spectroscopy. Co‐substitution of barium/strontium (Ba2+/Sr2+) and tungsten/manganese (W6+/Mn4+) resulted in lattice distortion of C1−xBSxBNWM ceramics. The results induce that the tetragonal crystal structure increase with increasing the co‐substitution cations. Isothermal impedance spectroscopy confirmed intrinsic thermally activated conduction in the system. The C1−xBSxBNWM ceramics with x = 0.15 exhibit a very high Curie temperature (TC ∼ 923°C), a reasonable piezoelectric coefficient (d33 = 13.3 pC/N). Remarkably, even after thermal annealing at temperatures up to 800°C, it still retains a high d33 of 13 pC/N. In addition, the C0.85BS0.15BNWM ceramic had a relatively high resistivity (3.82 × 106 Ω·cm, 500°C). The Ca0.85(Ba1/2Sr1/2)0.15Bi2Nb1.985(W3/4Mn1/4)0.015O9 ceramics make possible their application in high‐temperature acceleration transducers. [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]

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]

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]

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]

[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]

In ceramic injection molding, the conventional solvent‐debinding process encounters limitations such as solvent cost and environmental pollution. In this paper, a suitable thermal‐debinding process from room temperature to 250°C using carbon/alumina embedding powders with nano and submicron size was developed to remove the soluble binders replacing the conventional solvent debinding of injection molding ZrO2 ceramic. The effects of the embedding powders on microstructure and debinding ratio were studied in detail. The results showed that the main factor influencing debinding ratio was associated with the sufficient dispersing of mixed particles, which was characterized by the relative change ratio of tap volume. A debinding mechanism was proposed to explain the effects of carbon/alumina mixed powders on the debinding ratio and surface cracks. Based on the influencing mechanism, the debinded green part with the elimination of soluble binders and optimal surface was achieved using the mixed powders with C/A = 8/2 on the top and C/A = 4/6 on the bottom. [ABSTRACT FROM AUTHOR]

Powder synthesis is crucial for achieving the densification and facilitating widespread applications of high entropy carbide (HEC). Specifically, the production of fine particle‐size powders is essential to enhance the densification of HECs. Consequently, this paper proposes the molten salt method for synthesizing HEC powders. The synthesis process successfully yielded (Ta Nb Ti V) C powders with a particle size of only 0.44 µm at 1400°C, exhibiting a uniform distribution of each element. Subsequent densification of (Ta Nb Ti V) C within the 1700–1900°C temperature range was carried out using spark plasma sintering. It was observed that as the densification temperature increased, the densification and mechanical properties of HEC significantly improved. This study presents innovative ideas for the preparation of HEC at lower temperatures. [ABSTRACT FROM AUTHOR]

Ytterbium disilicate (Yb2Si2O7) is a potential environmental barrier coating (EBC) material. In this paper, the microstructure and phase composition of plasma‐sprayed Yb2Si2O7 coatings with different spraying process were systematically investigated to optimize the spraying power and spraying distance. Furthermore, in order to obtain Yb2Si2O7 coating with single phase, a certain proportion of SiO2 was added to the Yb2Si2O7 powder to compensate for the volatilization of SiO2 during plasma‐spraying process, and the influence of spraying powder composition on the microstructure and phase structure (composition and content) of Yb2Si2O7 coatings were also characterized in detail. The results showed that the Yb2Si2O7 coating was dense with fewer pores and cracks at the spraying power of 40 kW and the spraying distance of 100 mm. Yb2Si2O7 coating with the "sandwich" structure was composed of Yb2Si2O7, Yb2Si2O7 + Yb2SiO5, and Yb2SiO5 three microstructures, which was mainly caused by the volatilization of SiO2 in Yb2Si2O7 spraying powder. The Yb2Si2O7 coating contained 90.68 mol.% Yb2Si2O7 phase and 9.32 mol.% Yb2SiO5 phase after crystallization at 1300°C for 20 h. The coating was composed of Yb2Si2O7 phase and amorphous phase after SiO2 addition. Yb2SiO5 phase precipitated from the coating after heat treatment at 1300°C, and its content decreased with the increase of SiO2 content. The content of the Yb2Si2O7 phase was as high as 99.41 mol.% when SiO2 content was 10 mol.%, which would provide a scientific basis for further research on stoichiometric Yb2Si2O7 EBCs with excellent properties. [ABSTRACT FROM AUTHOR]

A large adiabatic temperature change along with a wide operating temperature region is usually required for the electrocaloric materials to fulfill their refrigeration function. In general, doping foreign ions into BaTiO3 is the frequently utilized strategy in order to obtain excellent electrocaloric materials for the practical application. In the current paper, BaTiO3 lead‐free ferroelectric ceramics were doped by Ca2+ and Sn4+ simultaneously in order to generate a coexistence state at room temperature, where ferroelectric domains and nanodomains exit. As a result, a large polarization and a wide operating temperature range were finally induced. It is found that Ba0.9Ca0.1Ti0.85Sn0.15O3 has a maximum adiabatic temperature change of 0.85 K and an excellent working temperature region (65 K, ∆T > 90% Tmax) was achieved under an electric field of 50 kV/cm. The above phenomenon indicates that the modified BaTiO3 ceramics can be a good potential electrocaloric material in the state of cross‐existence of ferroelectric domains and nanodomains. [ABSTRACT FROM AUTHOR]

The full matrix parameters of a piezoelectric material are crucial for designing and evaluating piezoelectric devices. However, due to their inverse problematic nature, commonly used single‐sample characterization methods heavily depend on the accuracy of initial values and mode matching. In this paper, we propose a quasi‐31‐vibrator method to directly evaluate these parameters by designing the sample geometry and establishing the relationship equation between the parameters. This approach completely bypasses the need for characteristic spectrum simulation and mode identification processes. Subsequently, we tested the full matrix parameters of PZT‐5H ceramics and compared the simulated impedance spectra with the measured ones. The presence of well‐fitting spectra validates the feasibility of the method. This method will contribute to characterize the parameters of new piezoelectric materials and advance the intelligent implementation of measuring full matrix parameters. [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]

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]

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]

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]

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]

The thermodynamics and kinetics of interdiffusion are analyzed for the case of glass ion exchange, a process by which alkali ions from a glass inter‐diffuse with different, usually larger, alkali ions from a surrounding salt bath. The spontaneity of the ion exchange reaction is driven by entropy production. This paper details the first derivation and quantification of the entropy produced during this process. We present models for the evolution of the ion concentration profile for both common and extreme conditions, validate against experimental literature, and derive the entropy produced due to ion exchange as a function of time, temperature, composition, diffusivity, and glass and salt bath dimensions. Results reveal that when considering typical industrial parameter sets, the entropy produced in the glass accounts for <10% of the total entropy production, with the entropy produced in the salt bath being the dominant factor driving reaction spontaneity. Using the equations derived in this work, one can calculate concentration profile and entropy production for a two‐ion interdiffusion process between a low‐viscosity liquid and materials including, by not limited to, glass‐forming systems. [ABSTRACT FROM AUTHOR]

Thermal barrier coatings have been widely employed in high‐temperature turbine blades to enhance their resistance against corrosion, oxidation, and foreign object damage. Yttria‐stabilized zirconia (YSZ) coatings, both conventional and nano‐structured, exhibit distinct characteristics. Notably, nano‐structured coatings demonstrate remarkable reductions in oxygen permeability and thermally grown oxide (TGO) layer thickness owing to the presence of nano‐zones (NZs). This paper focuses on elucidating the formation mechanisms, dispersion patterns, and behavior of NZs under varying conditions. Furthermore, it investigates the shock resistance performance of YSZ coatings subjected to furnace heating and water quenching. The findings reveal that the incorporation of NZs effectively restricts oxygen penetration and TGO growth and significantly enhances the overall performance of the coatings. [ABSTRACT FROM AUTHOR]

Relaxor ferroelectric single crystal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) has received extensive research and attention due to its excellent piezoelectric, electromechanical, and other properties. In particular, tetragonal relaxor ferroelectric single crystals have shown greater application potential in high‐temperature devices due to their higher Curie temperature and better stability. However, the low piezoelectric performance of tetragonal crystals also greatly limits its application, and research on its optical properties is not sufficient. In this paper, the tetragonal phase Sm–PIN–PMN–PT single crystal was obtained by the Bridgman method, and its piezoelectric and electro‐optical properties are studied. At the same time, we gave a complete set of piezoelectric, dielectric, and elastic coefficient matrices. The results show that the crystal has excellent piezoelectric and electromechanical properties. The piezoelectric coefficient can reach 905pC/N, the electromechanical coupling coefficient k33 is 85%, and the kt is 72%. The transmittance of the sample polarized along [001] direction can reach 66%. The effective electro‐optical coefficient γc is 60 pm/V at room temperature and can reach 86 pm/V at 70°C. It has a wide operating temperature range and stable performance with frequency variation, which has certain reference significance for application in new electro‐optical devices. [ABSTRACT FROM AUTHOR]

The effect of resting time on the rheological properties of cement suspensions is generally explained by early formed structure and overconsumption of polycarboxylate superplasticizers (PCEs). In this paper, we propose that the influence of resting time on the rheological properties is closely related to size variation of non‐absorbed PCE. To identify this, glass bead suspensions were prepared with various amounts of PCE and ionic solution, and their rheological properties were evaluated at various times. We found that the yield stress increases with time at higher PCE concentrations and higher ionic strength solutions. Adsorbed PCE during resting tends to bridge the particles rather than disperse them. In addition, it was found that hydrodynamic radius of PCE increased with resting time, and depletion forces resulting from non‐absorbed PCE size changes correlate well with the increased yield stress. [ABSTRACT FROM AUTHOR]

Thermal stability and phase transition rate are two important issues that restrict the engineering applications of phase change memories. In this paper, GeSb/Sb multilayer films were prepared by multilayer stacking, and their phase transition properties were investigated. GeSb/Sb multilayer films had higher crystallization temperature, better data retention, and lower resistance drift than pure Sb films, which indicated that they had excellent thermal stability and accuracy of resistance identification. The test results of X‐ray diffraction and atomic force microscopy showed that GeSb spacer layers could inhibit grain growth of Sb film layers, thus reducing the roughness and potential fluctuation of the film surface. X‐ray reflectivity experiments showed that the GeSb/Sb multilayer films before and after crystallization had small volume changes. The devices based on [GeSb(7 nm)/Sb(3 nm)]8 multilayer films could achieve reversible resistive transition operation between SET and RESET at a pulse width of 10 ns, showing satisfactory transition rate and operational power consumption. The low resistance drift and ultra‐fast phase transition speed make GeSb/Sb multilayer films one of the promising choices for phase change memories. [ABSTRACT FROM AUTHOR]

In this paper, synthesis and sintering of MAX phases in the Zr–Al–C system is described. Different mixtures of initial Zr/Al/C and Zr/Al/ZrC powders were used to synthesize the MAX phases of Zr2AlC and Zr3AlC2 compositions by a combined method (high‐temperature sintering followed by spark plasma sintering [SPS]). The highest content of the Zr3AlC2 MAX‐phase was obtained using initial Zr/Al/ZrC powders in a component ratio of 1:1.5:2—51.1 vol.%. The optimal temperature for the synthesis of a material based on the Zr2AlC MAX phase is 1525°C, and a material based on Zr3AlC2 is 1575°C. During subsequent SPS at a temperature of 1500°C, a pressure of 50 MPa, within 5 min, it was obtained a material containing up to 71.1 vol.% Zr3AlC2. The relative density of the samples synthesized and consolidated by the SPS method reaches 98.9%. The structure of the obtained synthesized MAX materials includes elongated grains of the composition Zr2AlC and Zr3AlC2, which determines their high strength. The influence of the sintering time and temperature on the formation of the MAX phase of Zr3AlC2 from the initial powders of Zr/Al/ZrC is shown. Zirconium carbide, as an intermediate phase, is always present in the final products. Due to the large evaporation of aluminum, the ZrAl2 phase is also present in the synthesis products. An excess of aluminum contributes to the greatest formation of the Zr2AlC and Zr3AlC2 phases during the combined synthesis. [ABSTRACT FROM AUTHOR]

This paper introduces a fast, low‐temperature, pressureless process to chemically bind ceramic parts with the help of infrared (IR) irradiation and phosphate binder condensation. Ceramic components are synthesized from slurries of ceramic powders and Al(H2PO4)3 binder that are irradiated with short‐waved IR light capable of heating the system to 350°C. This irradiation is found to be sufficient to drive phosphate condensation, binding the ceramic powders together within a matter of seconds. The IR‐irradiated components show an increase in density and Vickers hardness. Layer‐by‐layer spraying and irradiation is demonstrated as a route to additive manufacturing using various ceramic chemistries. While further optimization is needed to control desired microstructure, this process of using chemically bonded ceramic binders with IR heating for additive manufacturing shows the potential to find applications in various ceramic systems, including refractories, bone implants, electronics, and thermal barrier coatings. [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]

It is reported that the self‐forming CrTaO4 oxide scale can protect refractory high‐entropy alloys from oxidation, superior to Cr2O3. In this paper, the phase stability, mechanical, and thermal properties of three polymorphous phases of CrTaO4 are systematically investigated from first‐principles density functional theory calculations. The mechanical properties predicted using the strain–energy methods indicated that all three phases are mechanically stable. The temperature dependence of elastic constants and polycrystalline moduli of three phases demonstrated the thermal softening as temperature increase. The Helmholtz‐free energies as a function of volume and temperature are derived from phonon dispersions within the quasi‐harmonic approximation at six strained volumes. The calculated apparent bulk coefficients of thermal expansion of these three phases are evaluated, the highest value approximately 13.4× 10−6 K−1 within a temperature range of 500–2000 K for the rutile I41md phase. The lattice thermal conductivity calculated by the Debye–Callaway model suggested that the rutile type I41md phase has the lowest value of approximately 2.1 W/m/K at 1800 K. The other two phases, C2/m and P2/c, exhibit higher values due to relatively lower Grüneisen parameters and larger phonon velocities. The melting point of CrTaO4 is predicted to be between 1975 and 2449 K using ab initio molecular dynamics simulations. This work provides a comprehensive theoretical understanding of the thermodynamic, mechanical, and thermal properties for the new material CrTaO4 and serves as an example of a viable computational design strategy for improved oxidation resistance of refractory alloys at high temperatures. [ABSTRACT FROM AUTHOR]

The creation of robust joint among different materials with notably different coefficients of thermal expansion (CTE) is an urgent task for the development of the engineering, laser technology, and aerospace industry. In this regard, femtosecond laser welding is a promising technique for efficient adhesion‐free bonding of transparent materials. This paper reports on the laser welding of laser phosphate glass (CTE = 110 × 10−7 K−1) and spinel‐based glass–ceramic (CTE = 50 × 10−7 K−1) by the Bessel beam. Dependencies of weld geometric parameters on the pulse energy and scanning speed were investigated, and the laser exposure conditions were optimized for durable welding. The weld joints were tested on shear strength, which was shown to be as record high as up to 147 MPa. Atomic force microscopy, Raman spectroscopy, and elemental analysis were used to investigate the structure and morphology of the weld after its fracture, which revealed the laser‐induced amorphization of glass–ceramics and the formation of strong interconnection by laser‐driven mutual diffusion of two glassy phases. The results demonstrate the prospects for using femtosecond lasers for efficient industrial welding of a wide range of materials. [ABSTRACT FROM AUTHOR]

The mixed modifier effect (MME) is one of the most challenging puzzles in the field of oxide glasses, as there exists no universal quantitative theoretical model for accurately describing and predicting the nonlinear deviation of property values. In this paper, pairwise and ternary interactions are examined experimentally to understand the MME in a series of aluminosilicate glasses. By keeping the glass network former concentration constant and adjusting the molar ratios of three network modifiers (Na2O, K2O, and CaO), the MMEs in glass transition temperature (Tg), Vickers hardness (Hv), and activation energy (Ea) for aqueous dissolution for each modifier cation are investigated. We examine whether a pairwise interaction model is sufficient, or if ternary interactions also need to be included to predict the MME in these aluminosilicate glass systems. This work reveals that the pairwise model can be used to predict the MME for Tg in complex multiple‐modifier glass systems using only two‐body interaction factors. However, ternary mixed‐modifier interactions are present in other properties such as Hv and Ea. [ABSTRACT FROM AUTHOR]

Calcium sulfate (CaSO4), an essential retarder in cement, retards the hydration of tricalcium aluminate (C3A) and tetracalcium aluminoferrite (C4AF) phases. However, its retarding mechanism remains unclear. This paper focused on the adsorption of CaSO4f on C4AF and C3A surfaces based on isothermal calorimetry, the measurement of the ionic concentrations in a diluted system, and density functional theory to enhance the understanding of the retardation mechanism. The results showed that the retarding effect of CaSO4 on C4AF was stronger than that on C3A due to the slower CaSO4 consumption rate, lower driving force for CaSO4 adsorption, and surface coverage of Fe(OH)3 gel. The adsorption of CaSO4 hindered Ca dissolution more markedly on C4AF than C3A, which was pronounced on Fe‐free C4AF surfaces. The adsorption of CaSO4 weakened the affinity of water on C4AF and C3A surfaces, lowering the driving force for H2O adsorption. The adsorption of H2O and CaSO4 promoted the dissolution of Al on the [AlO6] octahedral surface of C4AF, which may be responsible for the maintenance of a higher Al concentration in the solution. Based on the above results, the adsorption of CaSO4 on initial C4AF and C3A hydration was explained. [ABSTRACT FROM AUTHOR]

High‐entropy strategy is a design that uses multiple elements to increase configurational entropy. As an emerging research field, high‐entropy was originally applied to metals, but it has shown great potential in inorganic nonmetallic materials. Since the first discovery of colossal dielectric permittivity in high‐entropy ceramics, it indicates that the high‐entropy strategy is feasible in dielectric ceramics. The multi‐ion solid solution will bring a broader space for the material structure and property tailoring. With the research of domestic and foreign scholars in high‐entropy dielectrics, we believe that entropic engineering can effectively regulate dielectric properties. The review paper explores the potential of the high‐entropy strategy in dielectric ceramics. It provides a detailed overview of the structural properties and the potential benefits of utilizing high‐entropy materials in dielectric ceramics. The review also covers the current research advancements in the field and provides insights into future directions for further development of high‐performance dielectric ceramics. [ABSTRACT FROM AUTHOR]

Recently, poled Na0.50Bi0.50TiO3‐BaTiO3 (NBT‐BT)‐based polycrystalline materials have been characterized as possessing a high degree of poling‐induced domain texture in their remanent state. This finding is suggested to be the reason for their stable mechanical quality factor at high‐vibration velocity, making them promising candidates for high‐power applications. The materials in consideration are prone to self‐heating and thermal run‐away, particularly at slightly elevated temperatures. Therefore, this paper evaluates the temperature dependence of the poling‐induced domain texture of (Na0.47Bi0.47Ba0.06)TiO3 (NBT‐6BT) doped with 0.5 mol% of Mg as compared to undoped NBT‐6BT. Its influence on small‐signal, large‐signal, and high‐power properties was investigated. To obtain a fundamental understanding of crystal structure, in‐situ synchrotron measurements were conducted as function of temperature to establish a relationship between structure and piezoelectric properties of both Mg‐doped and undoped NBT‐6BT materials. [ABSTRACT FROM AUTHOR]

In this paper, the gamma irradiation effect on the microstructure and physical performances of porous silica, including mechanical, thermal, and optical performances, are systematically investigated by using molecular dynamics and density‐functional theory‐based methods. The study of bond angle distribution, pair distribution function, coordination number distribution, and average ring size distribution show that, after gamma‐ray irradiation, the microstructure of porous silica is obviously modified. The tight packing of SiO2 tetrahedrons in the porous silica network is broken by gamma‐ray irradiation. Defects of three‐coordinated Si and non‐bridging oxygen are induced by gamma‐ray irradiation. Moreover, we find that the defects concentrations rapidly grow as gamma‐ray dose increases. The mechanical, thermal, and optical performances of porous silica are all seriously degenerated by gamma‐ray irradiation. Our results show that, for mechanical performance, Young's modulus, Bulk modulus, and Shear modulus first decrease and then keep stable as gamma‐ray dose increases, but the change of Poisson's ratio is slight. For thermal performance, the thermal conductivity decreases exponentially as gamma‐ray dose increases. For optical performance, light absorption coefficients increase exponentially and light transmittance drops as gamma‐ray dose increases in the working range (photon energy range around 3.5 eV) of inertial confinement fusion. Present work is expected to be valuable for studying the degradation mechanism of silicate materials under gamma radiation and developing gamma‐ray irradiation protection technology. [ABSTRACT FROM AUTHOR]

In this paper, we theoretically and experimentally reported a lead‐free pyroelectric infrared (PIR) detector using (Bi1/2Na1/2TiO3)‐BaTiO3(BNT‐BT) ferroelectric ceramics as the sensitive material. The variation of noise density, voltage response rate (RV), and specific detection rate (D*) with the modulation frequency under the current mode amplification circuit was investigated, and it was found that the lead‐free PIR detector showed high RV in the low frequency band. The RV and D* reached 1.51 × 105 V/W and 2.02 × 108 cmHz1/2W−1 at 10 Hz, respectively. The results were much superior to the PIR based on traditional commercial pyroelectric ceramics, indicating that BNT‐BT lead‐free ceramics have great potential in application to PIR detectors. [ABSTRACT FROM AUTHOR]

Calcium chloride is widely used in various fields of society because of its good chemical stability and non‐toxic properties. As an inorganic salt with low ductility at low temperature, it is never used to prepare bulk materials but is usually used to prepare energy storage materials. The work in this paper presents the first synthesis of a moldable calcium chloride ceramic‐like material (flexural strength up to 32 MPa) using calcium chloride. The process results in occurring ion‐dipole interactions between calcium chloride and glycerol by means of direct heating and forms supramolecular structure. Due to the presence of dynamic and reversible non‐covalent bonds, the bonds break upon heating bringing good flowability; the re‐established bonds upon cooling allow the formation of rigid materials. The preparation is also a green and recyclable process, as the molded material can be reshaped by heating. Such a brilliant moldable property reveals the potential of this new approach for the design and production of calcium chloride materials with adjustable shapes. [ABSTRACT FROM AUTHOR]