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In this study, the influence of curing temperatures (60, 80, and 100 °C) and sodium hydroxide concentrations molar (M) of (10 and 16) on the properties of geopolymer mortars, containing ceramic sanitary-ware waste (CSW) as the sole precursor was investigated. Microstructural and compositional properties were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Meanwhile, thermogravimetric analysis and its derivative (TGA/DTA) were conducted to assess the thermal stability of the geopolymer mortars. The compressive strength of the samples ranged from 0.5 MPa to 11.25 MPa, with the highest values recorded in samples with higher alkali concentration cured at 100 °C. Increasing the alkali concentration improved the flowability by 16 % and reduced the porosity from 18.41 % to 15.55 % in samples cured at 100 °C with 10 M and 16 M NaOH, respectively. This reduction in porosity, as confirmed by microstructural analysis, corresponded to a denser, more compact matrix associated with higher alkali concentrations. However, thermogravimetric analysis (TGA) revealed that higher NaOH concentrations led to increased thermal degradation at later ages. In the 16 M NaOH samples the weight loss exhibited a value of 11 % compared with 4 % weight loss of the 10 M NaOH samples. Additionally, curing at 60 °C and 80 °C for 24 h proved insufficient for complete hardening. These results highlight the importance of optimizing curing conditions and alkali concentrations for high-temperature applications. • Ceramic sanitary ware waste is a sustainable precursor for geopolymers. • Higher alkali concentrations enhance strength but increase thermal degradation. • Longer curing times at lower temperatures are needed for complete hardening. [ABSTRACT FROM AUTHOR]

This paper presents the results of the adhesion resistance before and after cyclic thermal treatments in NiCoCrAlY bond-coat (BC) coatings reinforced with dispersed SiC-ZrB 2 particles and conventional NiCoCrAlY. The ASTM-C-633 standard test method for the adhesion or cohesion strength of thermal spray coatings was used. The microstructure and morphology of the coatings were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Microhardness and coefficient of thermal expansion were also measured. The addition of SiC-ZrB 2 particles improved the long-term adhesion resistance by 1825 % compared to the system without reinforcement after 275 cycles. This improvement is attributed firstly to a self-healing mechanism and secondly to the lower thermal expansion coefficient (32.60 % lower) of the BC layer reinforced with SiC-ZrB 2 , which delayed the formation of cracks at earlier stages associated with CTE mismatch. [ABSTRACT FROM AUTHOR]

In this investigation the synthesis, structural and optical characterization of terbium-doped ZnO-ZrO 2 -ZnZrO 3 luminescent coatings, deposited by ultrasonic spray pyrolysis technique, are presented. These coatings were deposited at various substrate temperatures and were doped with different concentrations of the Tb3+ ions within the precursor solution. The XRD results for these coatings exhibited that their crystalline structure is subject to the deposition temperature. In the luminescence study, with an excitation wavelength of 270 nm the emission spectra were recorded, and all these spectra exhibit bands corresponding to the electronic transitions of trivalent terbium ions. When these samples were excited with 380 nm, the PL emission generated was reddish, probably produced by crystalline defects in the existing oxides. The concentration quenching effect appears at doping concentrations greater than 10 atomic percent inside the precursor solution. More information about the morphological and optical characteristics of these samples was obtained through techniques such as: SEM, TEM, EDS, and Diffuse Reflectance. Decay time study of the 544 nm characteristic green emission of Tb3+ ion was also obtained. [ABSTRACT FROM AUTHOR]

The high hardness and good wear resistance of Ti(C, N)-based cermets confer excellent applicability as cutting tools. However, the lack of in-depth research on the fracture mechanism limits further improvements in toughness. A typical commercial Ti(C, N)-based cermet with a core–rim structure was prepared through low-pressure sintering. The interface characteristics between the complex core, rim, and binder phases were characterized using transmission electron microscopy (TEM), while the actual hardness and modules of these phases were measured through in-situ nanoindenter assessments. The crack propagation behaviour of the cermet was analyzed using a 70° angle observation method combined with electron backscatter diffraction in scanning electron microscopy (EBSD/SEM). This study identifies a commonly occurring but long-overlooked fracture mode, termed "trans-rim" fracture. The experimental results were verified through simulation calculations. This novel idea offers insights into enhancing the toughness of Ti(C, N)-based cermets. [ABSTRACT FROM AUTHOR]

Bioactive glasses (BGs) have emerged as invaluable resources for bone tissue engineering due to their remarkable properties such as bioactivity, resorbability, cell compatibility, and osteoconductivity. However, these materials exhibit certain limitations when subjected to high temperatures, for their tendency to crystallize, thus leading to diminished bioactivity, reduced mechanical strength, and altered dissolution kinetics. One promising approach to counteract this problem is to reduce the alkaline element content in BGs while simultaneously adding strontium and magnesium. Building on previous studies of Bio_MS, a recently developed experimental formulation, we investigated the contributions of strontium and magnesium to the thermal, mechanical, and biological properties of various bioactive glasses, including commercially available options. Differential thermal analysis, heating microscopy, X-ray diffractometry, environmental scanning electron microscopy, measurement of the Young's modulus, simulated body fluid testing, cytotoxicity tests, cell viability, growth, adhesion and morphology were assessed through an integrated approach and compared for a complete evaluation of BGs, and of doped BGs, also undergoing thermal treatments. The results demonstrated improved thermal, mechanical and biological behaviors of the magnesium-strontium-doped BGs, thus paving the way for the development of BGs with enhanced biomedical perspectives. [ABSTRACT FROM AUTHOR]

In this study, 0.6Y 2 O 3 -0.4YCr 0.5 Mn 0.5 O 3 negative temperature coefficient (NTC) ceramics doped with different ZrO 2 contents were prepared using a two-step sintering method. The effects of Zr4+ content on the microstructure and electrical properties of 0.6Y 2 O 3 -0.4YCr 0.5 Mn 0.5 O 3 were mainly investigated. For the microstructure, X-ray diffraction (XRD) reveals the presence of two main crystalline phases in the samples: Y 2 O 3 and YCr 0.5 Mn 0.5 O 3. Scanning electron microscopy (SEM) reveals a clear two-phase appearance, and the porosity tends to decrease with the addition of ZrO 2. Combined with energy dispersive spectrometer (EDS) to derive the distribution of the elements, Zr4+ is mainly present in the Y 2 O 3 phase, with a small amount in the YCr 0.5 Mn 0.5 O 3 phase. In addition, the grain sizes of different groups were counted, and the grain size of Y 2 O 3 decreased from 2.73 ± 1.80 μm to 1.65 ± 0.93 μm with the increase of ZrO 2 content. For the electrical properties, the resistance-temperature curves were measured from 298.15 K to 1073.15 K, and all the samples exhibited NTC characteristics. And with the increase of ZrO 2 content, the resistivity increased from 1.91 × 107 Ω cm to 1.96 × 108 Ω cm, and the B 25/100 value decreased from 3315 K to 1310 K. In addition, the chemical state forms of the elements on the surface of the samples were analysed by X-ray photoelectron spectroscopy (XPS), and the valence states as well as the occupancy of the transition elements Cr and Mn were analysed in detail according to the principle of multiple splitting. Finally, the mechanism of influence on microstructure and electrical properties is explained by combining the theory of grain boundary migration and thermal ceramic conductivity. [ABSTRACT FROM AUTHOR]

Solid-state synthesis is widely used in exploratory research to study various structural modifications that affect the properties (critical temperature, critical current density, irreversibility field, etc.) of superconductors. The popularity of this method is due to its relative simplicity and availability of the necessary equipment. Combining solid-state synthesis and top-seeded melt growth allows us to increase the grain size in a Tm- and Nd-based 1-2-3 superconductor. Samples with a grain size up to 0.1 mm have been obtained. X-ray diffraction, scanning electron microscopy and magnetization measurements have been used for investigating this superconducting material. The magnetization width Δ M has increased significantly in the synthesized samples. However the temperature dependence of the intragrain critical current density and the pinning force scaling give evidences that the pinning mechanism in the obtained superconductor is essentially the same as in polycrystalline superconductors synthesized by standard solid-state technology. The increase in grain size in the synthesized samples is the main reason for the high values of Δ M. [ABSTRACT FROM AUTHOR]

In this work, the bioactive glasses are derived from biowaste resources such as corn husk ash, sugarcane leaves ashes, and eggshell powder via the melt quench method. The raw materials were melted in a platinum rhodium crucible at 1550 °C, followed by rapid cooling to obtain a glassy phase. In order to assess the in-vitro bioactivity, glasses were soaked in simulated body fluid at 37 °C for different time durations, i.e., 7,14, 21, and 28 days. Biocompatibility of these glasses was also tested on MG-63 cell lines using a 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT) assay test. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were used to analyze the hydroxyapatite (HAp) layer formation and the thermal stability of soaked samples. SEM micrographs showed the cauliflower and flakes type morphology of hydroxyapatite (HAp) on the glass surfaces after 7 days of soaking in SBF. The EDS analysis also confirmed the formation of a hydroxyapatite layer with a Ca/P ratio that varies from 1.6 to 3.9. MTT assay revealed the biocompatibility for different dosages (1, 2, 5, and 10 mg/ml) of the as-prepared glasses with MG-63 cell lines. The heat treatment of soaked glasses converts the amorphous HAp layer into a crystalline HAp layer, followed by its conversion in stable diopside as main and Ca 2.589 Mg 0.41 (PO 4) 2 as minor phase. The tested glasses exhibited good bioactivity and biocompatibility particularly higher CaO content glass, suggesting for use in bone regeneration applications. [ABSTRACT FROM AUTHOR]

Ceramic capacitors are widely studied and applied in the electronic industry. We utilized the sand-milling technique to produce a series of La-doped SrTiO 3 powders with varying particle diameters and investigated the effect of particle size on the resulting dielectric properties for the first time. We found that reducing the particle diameter significantly enhances the permittivity from approximately 7000 to 32000 (at 1 kHz, room temperature). Furthermore, a colossal permittivity of ∼32000 (at 1 kHz, room temperature), combined with ultra-high resistivity (>7 × 1011 Ω cm), low loss (0.004), and excellent frequency/temperature stability, were simultaneously achieved in the ceramic. Lastly, the sintering temperature is as low as 1360 °C, making it suitable for industrial production. By analyzing scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) results, we discuss the possible mechanism behind the enhancement of permittivity with increased sand-milling time. The low sintering temperature and highly controllable permittivity of the ceramics by adjusting the sand-milling time of the powders offer a new strategy for the scientific study and industrial application of materials with colossal permittivity. [ABSTRACT FROM AUTHOR]

The slag corrosion resistance and thermal shock and of MgO-C refractories are crucial in the steelmaking industry. The current study presents a novel approach to enhance these properties by incorporating reinforcing particles such as zircon and silicon carbide. MgO-C refractories containing various amounts of ZrSiO 4 and SiC were prepared and subjected to slag corrosion and thermal shock tests. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were used to characterize the microstructure and chemical composition of the samples. The findings demonstrated significant improvements in the overall performance of the refractories with the addition of zircon and silicon carbide. Thermal shock resistance increased from 11 cycles for MgO to 18 and 15 cycles due to the increased fracture toughness and altering crack propagation paths with the addition of ZrSiO 4 and SiC particles. The formation of a CaZrO 3 phase within pores significantly improved slag corrosion resistance. This led to a reduced slag penetration depth and a thinner decarburized layer compared to the unreinforced MgO-C refractory. SiC decomposition formed a protective silica layer, while zircon particles locked MgO grain boundaries, further enhancing corrosion resistance. The study proposes a corrosion mechanism based on the formation of microstructure containing dense and decarburized layers. These findings highlight the potential of reinforcing particles to improve the performance of MgO-C refractories in steelmaking applications. [ABSTRACT FROM AUTHOR]

With the waste of resources caused by human activities, it has gradually become an increasingly prominent social problem. The development of self-healing polymers in the field of insulation has attracted widespread attention. Develop polymer matrices with efficient healing efficiency and sound insulation properties to achieve green and sustainable resource conservation. In addition, improving the dielectric properties of intrinsic self-healing matrices has been a hot topic. In this work, we developed a new PEI matrix-modified self-healing polymer substrate that provides a breakdown field strength of 240 kV/mm and self-healing properties at room temperature, this has significantly improved the dielectric properties over other previously reported self-healing polymers. In addition to the abovementioned performance, we found significant differences in thermodynamic behavior in the synthesized end-modified polymers. By dielectric characterization (LCR), the breakdown composite can be left at room temperature for 60 min, and the material can recover 80 % of the initial properties without external intervention(This is demonstrated by the fact that its DC conductivity at 60 min of autonomous healing was significantly changed from that of the freshly electrically pierced DC conductivity and remained around 5.38 × 10−11 S/cm for a longer period of time thereafter). The microscopic morphology of the modified PEI matrix was observed by scanning electron microscopy (SEM) and EDS surface elemental analysis, which further supports the existence of metal coordination structures. These findings can further deepen the thinking of self-healing dielectric composites. The work inspired by this may break the limits and take self-healing composite dielectric materials to a new height. [ABSTRACT FROM AUTHOR]

xSrTiO 3 -(1-x)SmAlO 3 (ST-SA) (x = 0.4, 0.5, 0.6) microwave dielectric ceramics were prepared by solid-state reaction method and the microwave dielectric properties (ε r , Q × f , τ f) were studied. The 0.4ST-0.6SA component with better Q × f and τ f was selected and the effects of different ywt % Ga 2 O 3 (y = 0.5, 1.0, 1.5, 2.0, 2.5) doping on the phase structure, microstructure, and microwave dielectric properties of ceramics were investigated. X-ray diffraction analysis showed that Ga3+ mainly replaced Ti4+ site when y ≤ 0.5, and when y > 0.5, Ga3+ start to replace Al3+ site. The best grain uniformity of the ceramics was observed at y = 2.0 by scanning electron microscopy testing. Raman spectroscopy shows that the stability of the oxygen octahedron is improved after Ga 2 O 3 doping with increased Q × f value. The change of Ga 2 O 3 doping amount also affects the dielectric properties of ST-SA ceramics. The optimum Q × f value of the ceramic is improved by about 50% from 10,278 GHz (7.465 GHz, 0.4ST-0.6SA) to 15,712 GHz (6.950 GHz, 0.4ST-0.6SA-2.0 wt% Ga 2 O 3) with improved dielectric properties (ε r = 36.14， τ f = 4.17 ppm/°C). [ABSTRACT FROM AUTHOR]

A method to obtain sodium titanate nanoribbons starting from a mixture of brookite and anatase TiO₂ nanopowder is described. As-prepared TiO 2 nanopowder with a major brookite phase was used as a precursor in an alkaline hydrothermal approach, where the temperature was kept at 200 °C. The influence of hydrothermal treatment and consequent annealing temperature (T = 500 °C) on the crystal structure, phase composition, and morphology of samples were investigated by X-ray powder diffraction (XRPD), Raman and FTIR spectroscopy, and electron microscopy techniques (FESEM, HRTEM). All these methods point out that the hydrothermally treated sample, containing the NaTi 3 O 6 (OH)(H 2 O) 2 , Na 2 Ti 3 O 7 , and Na 2 Ti 9 O 19 , is dominated by layer-structured sodium hydroxititanate dihydrate. The annealing leads to the formation of rare sodium titanates, Na 3 Ti 6 O 13 and Na 2 Ti 9 O 19 , with tunnel structures where the hexatitanate with increased sodium content prevails. The photocatalytic activity of synthesized nanostructures was tested in the degradation process of Reactive Orange (RO16) azo-dye upon UV excitation. It appears that photocatalytic activity is lower after hydrothermal treatment, but subsequent annealing makes sodium titanate nanoribbons faster in the degradation of RO16. The research implies that these sodium titanate nanostructures are promising photocatalytic materials and should be considered in the future for removing different pollutants from water. [ABSTRACT FROM AUTHOR]

Obtaining high-purity MAX-phase powders is a challenging issue. Therefore, in this article, the effects of two key parameters, including mechanical activation time (1, 2, and 3 h), and preheating temperature (800 and 1000 °C) were investigated on the formation mechanism of Ti 2 AlC MAX phase using mechanically activated (assisted) self-propagating high-temperature synthesis (MA-SHS) combustion method through thermal explosion mode. For this aim, a powder mixture of titanium, aluminum, and carbon with a stoichiometry ratio of (2:1:1) was used. Differential thermal analysis (DTA) was carried out to evaluate the effect of mechanical activation and preheating temperature of the formation temperature of the target MAX phase. Subsequently, the microstructural, phase analysis, chemical composition, and determination of surface chemical states studies were carried out through scanning electron microscopy (SEM), X-ray energy distribution spectroscopy (EDS) transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and X-ray photoelectric spectroscopy (XPS), respectively. DTA results illustrated that applying mechanical activation alters the formation temperature, which leads to an increase in the purity of the MAX phase. The quantitative measurements were carried out using the Rietveld method to determine the purity of the achieved MAX phase. The results indicated that samples subjected to 2 h of mechanical activation at a preheat temperature of 1000 °C exhibited to contain 96.1 % of Ti 2 AlC MAX phase, which is the highest value among other specimens and the lowest amount of secondary and oxide phases (3.9 % of TiC) during the combustion synthesis process compared to other samples. [ABSTRACT FROM AUTHOR]

The mechanical properties and microstructure of double-hard-phase TiB 2 –25-wt.%-TiC–20-wt.%-CoNi cermets prepared at different temperatures were investigated by performing scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The results showed that the transverse rupture strength, indentation fracture toughness, hardness, and relative density of the cermets reached the maximum values of 1654 MPa, 11.06 MPa m1/2, 90.1 HRA, and 99.42 %, respectively, when the sintering temperature was 1462 °C. Solid- and liquid-phase sintering occurred at temperatures below and above 1354.5 °C, respectively. The cermets were composed of TiB 2 , TiC, TiB, and CoNi phases when sintered at 1440 °C and below, but the TiB phase disappeared when sintered at 1462 °C and above. Both TiB 2 core–(Ti, Co, Ni)B rim and TiC core–(Ti, Co, Ni)C rim structures appeared in cermets sintered at 1440 °C and above. In addition, a few TiC core–(Ti, W)C inner–(Ti, W, Co, Ni)C outer double rim structures were formed. A coherent interface was found between the (Ti, Co, Ni)B rim and TiB 2 core. A thin CoNi amorphous metallic layer existed at the interface between the (Ti, Co, Ni)C rim and TiC core. In addition, amorphous CoNi was observed in the interfacial region between the CoNi binder and (Ti, Co, Ni)C rim phase and inside the CoNi binder phase. These multi-interface and core–rim structures resulted in excellent strength and toughness of the cermets. [ABSTRACT FROM AUTHOR]

Hexagonal ferrites have drawn significant attention due to a broad range of telecommunication and stealth technology applications. β-Type hexagonal ferrites are rarely used in various technological applications. In the current work, Nd3+ substituted polycrystalline β-type hexagonal ferries with composition LiFe 11-x Nd x O 17 (x = 0.0–0.04, ∇ x = 0.01) were prepared using the sol-gel method. All prepared samples were sintered at 1000 °C for 4 h. The influence of Neodymium (Nd3+) on its structural, electrical, and dielectric properties was investigated. Lattice parameters (a, c) and V cell increased with varying Neodymium substitution levels. The crystallite size was measured in the range of 38–42 nm. Fourier Transform IR (Infrared) spectroscopy exposed the presence of two spectral bands at 416 to 449 cm−1 and 449 to 489 cm−1. XPS (x-ray photoelectron spectroscopy) analysis verified the presence of metal ions and their chemical states in all prepared samples. The dielectric constant, loss, tan δ, and σ ac (ac-conductivity) decreased by increasing Nd3+ content. Jonscher's power law explains the conduction mechanism of charge carriers in all fabricated samples. The influence of relaxation time and grain boundaries on the electrical characteristics of prepared nanomaterials was investigated by impedance analysis. SEM (scanning electron microscopy) confirms the successful formation of β-hexaferrite nanomaterials. A minimum reflection loss of −32.08 dB was observed at 1.5 GHz for the x = 0.04 sample. This minimum reflection loss evidenced the novelty of the research and suggested their usefulness in high-frequency microwave applications. All samples investigated in this research work are suitable for high-frequency applications, multilayer chip inductors, and EM interference shielding. [ABSTRACT FROM AUTHOR]

In this article, a green pigment Bi 1.95-x Pr x W 0.05 MoO 6+δ (x = 0.1–0.5) co-doped with Pr and W was developed using high temperature solid-phase synthesis method. The microstructure, color performance, and optical characteristics of the novel pigment was analyzed using x-ray diffraction instrument (XRD), field-emission scanning electron microscopy (FESEM), L∗ a∗ b∗ color date, and ultraviolet–visible–near infrared light spectrophotometer. The results indicate that all the samples possess a monoclinic structure, characterized by the space group P21/c(14). Compared to Bi 2-x Pr x MoO 6+δ doped solely with Pr 6 O 11 , the Pr/W co-doped Bi 2 MoO 6 pigment demonstrates superior green coloration. The solar reflectance in the near-infrared region of all pigment samples exceeds 80 %, highest value reaches 92.82 %. In thermal insulation tests, the temperature difference between the Bi 1.95-x Pr x W 0.05 MoO 6+δ pigment coating and a blank galvanized sheet reaches up to 10.3 °C after 60 min under infrared lamp irradiation. The color difference Δ E∗ of the pigment powder after immersion in acid and alkali solution and high-temperature calcination are less than 5, indicating good chemical stabilities in acidic, alkaline and high-temperature environments. To our knowledge, Bi 1.95-x Pr x W 0.05 MoO 6+δ has the highest reflectivity among green pigments without toxic metals. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aims to improve the mechanical properties of biocompatible ceramic materials, which are known for their superior potential to integrate with bone compared to metallic implants. However, achieving sufficient mechanical strength, particularly for weight-bearing areas, poses a challenge. Hydroxyapatite (HA) powder is synthesized, taking into consideration the mechanical mixing and aging effects to achieve the desired composition and properties. The synthesized HA powder undergoes calcination under various atmospheres to assess its impact on the crystal structure. The study also explores the coating of HA particles with silicon dioxide (SiO2) using tetraethyl orthosilicate (TEOS) to enhance surface modification and wettability. This process results in a triphasic powder consisting of HA, tricalcium phosphate (TCP), and calcium phosphate silicate (CPS). The morphology of the powder is analyzed using techniques such as energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Moreover, a refined sintering procedure is developed to minimize cracking volume, leading to a significant 117 % increase in compressive strength compared to commercial materials. Finally, the powder is optimized for 3D printing by adding water, simplifying its use in biomedical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Ce 0.8 Sm 0.2 O 2-δ (wt.70 %)-Sm 0.6 Sr 0.4 Fe 1- x Cu x O 3-δ (wt.30 %) (SDC-SSFC) dual-phase oxygen permeable membranes were prepared by one-pot EDTA-citric acid combined complexing method. Effects of copper doping content on crystallographic phase, microstructure and oxygen permeability were deeply investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDXS). Systematic studies reveal that SDC as oxygen ion conductors and SSFC as electron conductor display an excellent synergistic effect only if a suitable doping content of copper was adopted. It can be found that Ce 0.8 Sm 0.2 O 2-δ -Sm 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ exhibits the highest oxygen permeation flux of up to about 0.61 ml cm−2 at 950 °C and lower oxygen permeation activation energy, which displays nearly a two-fold increase in oxygen permeability compared with the sample without any copper doping. If the copper doping content in B-site of SSFC perovskite exceeds about 30 %, a third phase, i.e., CuO, would appear in the bulk of SDC-SSFC dual-phase membrane and the grain size of CuO tend to gradually increase which would degrade the oxygen permeability of SDC-SSFC dual-phase membrane. Kinetical analysis showed that the critical membrane thickness (L c) of Ce 0.8 Sm 0.2 O 2-δ -Sm 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ membrane is close to approximately 0.6 mm, i.e., if the membrane thickness is larger than 0.6 mm, its rate-determining step would transform into the bulk-diffusion exchange from surface exchange. Meanwhile, Ce 0.8 Sm 0.2 O 2-δ -Sm 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ membrane exhibits a stable oxygen permeation flux of up to 0.32 ml cm−2·min−1 in pure CO 2 atmosphere for more than 120 h without any degradation. [ABSTRACT FROM AUTHOR]

Diameter-controlled growth of monoclinic gallium oxide nanowires was performed by chemical vapor deposition technique. Prior to growth, a thin layer of Au films was fabricated, SEM images indicated that Au could converge nanoparticles to govern the growth of β-Ga 2 O 3 nanowires. The SEM images revealed both diameter and length of β-Ga 2 O 3 nanowires strongly depended on the growth temperature. Nanowires grown at 1100 °C temperature have the minimum diameters and uniform lengths, compared with those grown at 900 °C and 1000 °C. The reasons are that a combination and a competition of vapor-liquid-solid (VLS) and vapor-solid (VS) mechanism occur in the growth process. High temperature would provide enough energy to make Ga and O atoms grow along one-dimensional axial orientation following the VLS mechanism. However, low temperature confines atoms at the nanowires interface and enhance sidewalls coalescence following the VS mechanism. X-ray diffraction (XRD) patterns and refinement indicated that the grown samples were of high crystallinity and had intrinsic oxygen vacancies. Photoluminescence spectra were examined and then followed by Gaussian fitting. Through analysis, the emission peaks were considered to originate from intrinsic oxygen vacancies and Ga-O vacancy pairs, consisting with the XRD refinement results. β-Ga 2 O 3 nanowires was coated on the interdigitated electrode, the response to the ultraviolet light and oxygen was studied. [ABSTRACT FROM AUTHOR]

Herein, MgO–12 % TiO 2 (w) ceramics with different contents of Bi 2 O 3 –CuO sintering aid were prepared using a solid-state method. The effects of the sintering aid content on the sintering temperature and the dielectric and mechanical properties of the ceramics were studied. The material was characterized using scanning electron microscopy and X-ray diffraction and Precision LCR tester and universal testing machine and Archimedes drainage method. When the Bi 2 O 3 –CuO content was less than 9 wt%, the ceramic sample has higher dielectric properties. When the Bi 2 O 3 –CuO content was greater than 9 wt%, the dielectric properties will deteriorate. This is because Bi 2 O 3 participates in the chemical reaction between MgO and TiO 2 , forming a high dielectric loss Bi 4 Ti 3 O 7 phase. At high temperatures, Cu2+ can easily change valence to Cu+, promoting oxygen vacancies and increasing dielectric loss in ceramic samples. The introduction of Bi 2 O 3 –CuO produces new MgTiO 3 , Mg 2 TiO 4 , and Bi 4 Ti 3 O 12 phases in the sample structure, resulting in a structure in which the MgO grains in the sample are surrounded by the new phases that appear around them. This structure fills the pores, increases density, enhances mechanical properties. The dielectric properties of the ceramics were the when the sintering temperature was 1050 °C, and the Bi 2 O 3 –CuO content was 3 wt%. The dielectric constant and dielectric loss were 11.19 and 1.17 × 10−4, respectively. The bending strength of the ceramic sample increased from 138.72 MPa to 179.64 MPa when the Bi 2 O 3 –CuO content was increased from 3 wt% to 15 wt%. The Bi 2 O 3 –CuO sintering aid enables MgO to be better applied in ceramic substrates. [ABSTRACT FROM AUTHOR]

The Ag-SnO 2 contact material is widely regarded as the most promising environmental friendly electrical contact material. However, during the make and break operations, SnO 2 particles rising to the surface can cause increased contact resistance and temperature rise, which affects the service life of the contact material. In this study, a three-dimensional (3D) Ni skeleton reinforced Ag-based contact material with CuO-coated SnO 2 are successfully fabricated via powder metallurgy technology. The basic physical properties of the novel contact material were tested and the microstructures and arc erosion morphologies were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The research demonstrated that the hardness and electrical conductivity of the novel contact material are 128.9 HV and 46 %IACS, respectively. It can be observed that the SnO 2 -rich phase is uniformly distributed in the Ag matrix without significant upward after arc erosion, which indicates that the SnO 2 @CuO core-shell structure effectively enhances the wettability between Ag and SnO 2. Meanwhile, the study revealed that the Ni phase uniformly distributed at the interface of the Ag phase during the arc erosion process, indicating that the 3D Ni skeleton structure effectively impedes the expansion of the Ag molten pool and improves the anti-arc erosion performance. [ABSTRACT FROM AUTHOR]

A SiC-SiO 2 nano-composite coating was prepared via a novel liquid-phase plasma-assisted particle deposition and sintering (LPDS) method to enhance the oxidation resistance of the Ti-6Al-4V alloy. For comparison, a conventional plasma electrolytic oxidation (PEO) ceramic coating is fabricated on the Ti-6Al-4V alloy. The microstructure and formation mechanisms of both ceramic coatings were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results indicated that the thickness of the SiC nano-composite coating (∼40 μm) increased significantly by 285 % compared to the PEO coating (∼14 μm). The microstructural evolution and isothermal oxidation performance of the PEO and SiC-SiO 2 nano-composite coating were comparatively investigated at 800 °C. After 100 h, the thickness gain of the SiC-SiO 2 nano-composite coating (∼14 μm) was lower than that of the PEO coating (∼26 μm). The improved oxidation performance is primarily attributed to the outermost layer containing abundant SiC nanoparticles, which transform into SiO 2 during the oxidation process and effectively inhibiting the inward penetration of oxygen. [ABSTRACT FROM AUTHOR]

In this research, the accumulative roll bonding (ARB) technique was employed as a severe plastic deformation method to manufacture a unique bi-metal Pb/W composite reinforced by Co 3 O 4 ceramic oxide. For this purpose, composites with different amounts of reinforcement particles (0.25, 0.5, 1, 1.5, and 2 wt%) were successfully produced using the ARB process (up to 10 cycles). Also, the mechanical properties were evaluated using microhardness, tensile, and shear punch tests. For microstructural investigations, the X-ray diffraction method (XRD), transmission electron microscopy (TEM), and fractography analysis by scanning electron microscopy (SEM) were employed. The Pb-0.5%W/Co 3 O 4 following 10 ARB cycles exhibited optimal mechanical and microstructural properties. For this composite, the tensile strength showed a markable increase of 2.17 times, yield strength by 4.7 times, shear strength by 3.6 times, and hardness by 4.2 times compared to the pure Pb sample subjected to the same ARB cycles. However, the strain was reduced by 3.85 times. These enhanced properties are also followed by increased stiffness and improved anode dimensional stability, creep resistance, and operational lifespan. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, x ZrB 2 -AlCoCrFeNi (x = 0,5,10,15) (wt%) based high entropy alloy (HEA) composites were prepared by Spark Plasma Sintering (SPS). The influence of ceramic particle ZrB 2 content on the densification behavior, microstructural evolution, and mechanical properties of the composites was investigated through scanning electron microscopy, X-ray diffraction, and mechanical performance testing. The results indicate that the HEA composites undergo a phase transformation, from (FCC + BCC + B2) structure to (FCC + BCC + B2+Laves) structure with the addition of ZrB 2. The incorporation of ZrB 2 facilitates the emergence of the Cr precipitate phase, and the grain size of this phase enlarges as the ZrB 2 content rises. Additionally, when the ZrB 2 content is 10 %, the maximum compressive strength reached 2071 MPa. Furthermore, at the ZrB 2 content of 15 %, the composite material achieves a maximum densification of 99.13 % and a maximum hardness of 1222.2 HV. [ABSTRACT FROM AUTHOR]

In this research, a two-step hydrothermal technique is used to fabricate a NO 2 gas sensor based on MoS 2 nanoflowers with SnO 2 nanoparticles. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) , were used to determine the morphologies, nanostructures, and compositions of the materials. The nanocomposites consisting of MoS 2 /SnO 2 demonstrated a remarkable sensing response (38.6) towards 100 ppm of NO 2. Moreover, the nanocomposites showed a rapid response and recovery time (42/147 S) when exposed to 100 ppm at temperature (250 °C). The MoS 2 /SnO 2 nanocomposites demonstrated exceptional selectivity to NO 2 against CO, NH 3 , and H 2 S, as well as demonstrated good repeatability. The significant gas detection characteristics could potentially be controlled by the distinctive structures of thin layers assembled into flower-like formations of two-dimensional MoS 2. The multi-joint nanostructures promote the process of transferring the electrical charge of the carrier and the response to MoS 2 /SnO 2 and NO 2. The fabricated sensors are considered as potential candidates for the commercial in the nitrogen dioxide gas-sensing applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In the present research, it is reported that ball milling technique can be applied to enhance the photocatalytic properties of MnO and ZrO 2 metal oxide powders (MZOx) furthermore the fabricated photocatalyst can be used for the degradation of tetracycline (TTC). XRD analyses revealed that increasing the milling time resulted in the formation of a pure metallic Mn crystal phase, which boosted the antibiotic degradation rate. It was confirmed by SEM technique that the morphological structures of the particles were generally small and uniform. The band gap energy was calculated as 3.70 eV for the hybrid metal oxide. Additionally, the adsorptive and photoluminescence features were illuminated via DRS and PL analyses. The effect of milling time had a major impact on the photodegradation rate of TTC, and the 8 h milling sample (MZOx-8h) exhibited the highest catalytic degradation activity (79.4 %). Low photocatalytic activity was obtained at acidic pHs and increased at alkaline pHs. The presence of H 2 O 2 sharply decreased photocatalytic process time (60 min) and 94.3 % of the TTC was degraded at 7.5 mM H 2 O 2. The photocatalytic degradation process proceeded through superoxide radicals and was supported by holes. The stability of MZOx-8h almost remained constant (70.02 %) even after seven cycles. It was determined that the presence of oxalic acid positively affected the progress of TTC degradation reactions. Further, practical application areas were investigated and MZOx-8h doped on support materials was found to be suitable for such applications in proportion to the doping ratio. Finally, it was demonstrated that MZOx-8h exhibited remarkable performance in photocatalytic reactions of different types of organic pollutants. The synergistic nature of MnO and ZrO 2 with the contribution of ball milling time effect resulted in high photocatalytic activity. • High purity metallic Mn phase was successfully synthesized by ball-milling. • MZOx was used for the first time in TTC photodegradation. • TTC degradation was stable in the seventh cycle. • The different organic pollutants were removed with high efficiency. [ABSTRACT FROM AUTHOR]

Lanthanum iron oxide (LaFeO 3) nanoparticles, doped with yttrium (Y) at the A-site and nickel (Ni) at the B-site, were synthesized using a sol-gel method at 600 °C. This study focuses on the synthesis of nanocrystalline La 1−x Y x FeO 3 (Y doped LaFeO 3), LaFe 1−x Ni x O 3 (Ni doped LaFeO 3) and La 1−x Y x Fe 1−x Ni x O 3 (Y/Ni doped LaFeO 3) materials, where x = 0.01. The Synchrotron-based XRD analysis confirmed the single-phase formation of orthorhombic LaFeO 3 (Pbnm space group) in each sample. The characterization through scanning electron microscopy and EDX revealed grains of irregular shape with an average particle size of around 200 nm. Optical properties were explored using UV–Visible spectroscopy, indicating a band gap of 1.7 eV for the pure sample. Additionally, the photocatalytic properties of the synthesized nanoparticles were evaluated for dye degradation. Electrical properties were systematically examined using impedance spectroscopy across a frequency range of 1 Hz–10 MHz at room temperature. The effect of doping on crystal structure and possible implications on dielectric and photocatalytic properties were studied. The complex impedance diagram displayed a depressed semicircle, suggesting non-Debye relaxation processes. A correlation was established between impedance and UV–Vis spectroscopy. However, the current literature lacks a comprehensive investigation for isovalent i.e. +3 substitution at A and B site simultaneously for dye degradation properties of LaFeO 3 -based materials. This study addresses this research gap by systematically exploring the influence of separate as well as simultaneous Y+3 and Ni+3 doping on the structural, optical, electrical, and photocatalytic characteristics of LaFeO 3 nanoparticles, thereby providing valuable insights for the development of advanced functional materials for environmental applications. It was found that Y+3 dopants had a notable impact on the dye degradation properties for Mythlene blue dye at room temperature. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) of NiTi alloys has attracted significant attention for its exceptional forming precision and suitability for processing complex medical implant structures. However, challenges such as the excessive release of Ni2+, bioinertness, and insufficient antibacterial ability have emerged as primary factors impeding the application of NiTi alloy in the medical field. To address these issues, the silver-doped dicalcium phosphate dihydrate (Ag-DCPD) coating is electrochemically deposited on the LPBF-NiTi alloy surface for the first time. The study investigates the effects of varying Ag doping content (2 %, 4 %, and 6 %) on morphology, corrosion resistance, biomineralization, and long-term stability of DCPD coating using scanning electron microscopy (SEM), electrochemical analysis, and immersion tests. Results show that the 4Ag-DCPD coating exhibits the most uniform and dense surface morphology, excellent corrosion resistance, and biomineralization. The corrosion current density (I corr) is two orders of magnitude lower than that of the LPBF-NiTi alloy matrix (from 1.1 × 10−6 to 1.4 × 10−8), and a dense hydroxyapatite (HA) layer forms after immersion testing. In vitro cell experiments indicate that the 4Ag-DCPD coating maintains high cell viability, favorable cell morphology, and excellent biocompatibility. Additionally, the 4Ag-DCPD coating demonstrates effective antibacterial activity against Escherichia coli (79.75 %) and Staphylococcus aureus (69.33 %), which reduces the risk of implantation infection. Overall, the 4Ag-DCPD coated LPBF-NiTi alloy shows promising clinical application potential as a medical implant. [Display omitted] [ABSTRACT FROM AUTHOR]

In the present study, the boron carbide ceramics reinforced with silicon carbide fibers (B 4 C-SiC f) were fabricated by incorporating various contents of SiC f ranging from 2.5 to 10 wt%. The B 4 C-SiC f powder mixtures were sintered using the Field Assisted Sintering Technique (FAST), also known as Spark Plasma Sintering (SPS), at temperatures of 1800 °C and 2000 °C for 5 min by applying a pressure of 70 MPa in argon atmosphere, while heating and cooling rates were maintained at 100 °C/min and 50 °C/min, respectively. The influence of the initial powder ratio on the sintering behavior, relative density, microstructural development, and mechanical properties of the obtained B 4 C-SiC f composites was investigated. The results indicated that the sintered ceramic materials contained only the initial compounds, i.e. B 4 C and SiC phases. Scanning Electron Microscopy (SEM) showed that the sintered composites consisted of densely compacted B 4 C grains. The highest relative density (>99 %) was achieved for the sample with 95 wt%B 4 C and 5 wt%SiC f , sintered at 2000 °C. Depending on the constituent content and the densification temperature the obtained composites demonstrated hardness values ranging from 29 to 43 GPa. The maximal hardness was attained in the composite with 95 wt%B 4 C sintered at 2000 °C. To assess the performance of the composites under extreme conditions, the ablation resistance was evaluated using a flowing oxyacetylene torch test. The material containing 5 wt%SiC f exhibited superior ablation resistance when compared to the other compositions. The attained results of this study showed that the SPS technique is a highly effective method for the densification of additive-free B 4 C-SiC f ceramic composites, showcasing promising properties for applications in extreme environments. [ABSTRACT FROM AUTHOR]

An A site disordered rare earth-based perovskite-derived structured new compound is synthesized using low-cost solid-state reaction method. The phase formation of the desired compound is established through the X-ray diffraction technique. Rietveld analysis of the obtained XRD data confirmed that the compound exhibits orthorhombic symmetry with pbnm space group which is further supported through Raman spectroscopic analysis. The surface morphology and microstructure analysis of the synthesized compound is carried out using scanning electron microscopy approach. The optical properties study done through UV–Visible absorption spectroscopy suggests possible application in optoelectronic devices. The frequency and temperature dependence of dielectric properties are studied for the analysis of electric polarisation in the sample. Electrical properties study conducted through complex impedance spectroscopy approach disclosed the dominant contribution of grain to the electrical response of the material with temperature dependent relaxation process in the compound. The effect of temperature on the dc resistance is further analysed to find the suitability of the material for thermistor application. The frequency dependent data of ac conductivity follows Jonscher's power law. The temperature dependent ac conductivity graph was used to estimate the activation energy in order to identify the specific charge species engaged in the ac conduction process. [ABSTRACT FROM AUTHOR]

We hypothesized that we could prepare ZnO nanoparticles (ZnO NPs) as a biomedical application treatment of zinc deficiency in human populations. In this study, we report a formulation prepared using a low-cost method for the green synthesis of ZnO NPs by utilizing the medicinal species Salvia fruticosa as natural raw material and Zn(NO 3) 2 ∙6H 2 O as a Zn source. The final product was identified and characterized by elemental analysis using X-ray energy-scattering spectroscopy (EDS), ultraviolet–visible spectroscopy (UV-VIS Spectroscopy), X-ray powder diffraction (XRD), and morphometric analysis using scanning electron microscopy (SEM). Finally, crystallization was studied using transmission electron microscopy (TEM). Afterward, ZnO NPs thus produced were utilized for foliar spraying on S. fruticosa open cultures, and Zn fortification in the foliage. Then, their effects on the biosynthesis of essential oils, and Zn bioavailability to humans were studied through different modes of consumption. ZnO NPs produced using our method were spherical while some were hexagonal, with an average size of approximately 22 nm, based on XRD results. The green synthesis method devised in this study afforded ZnO NPs from Zn(NO 3) 2 ∙6H 2 O with a 95 % yield, and consequently yielded economic benefits with respect to the current market prices. Foliage Zn fortification and the desired features were successfully achieved using ZnO NPs, and the proper mode of consumption of this medicinal plant has been recommended in this study. In conclusion, the methodology described in this study enables eco-friendly green synthesis of ZnO NPs at a low cost using S. fruticosa and puts forward a contemporary and integrated biomedical use of ZnO NPs to treat disorders resulting from or related to Zn deficiency. [ABSTRACT FROM AUTHOR]

Microcrystalline cast stone is a silicate inorganic nonmetallic material prepared via a melting–casting–crystallization process using slag as the main raw material and appropriate nucleating, quenching, and tempering agents. However, crystallization of the microcrystalline cast stone causes overall shrinkage, producing defects such as holes on the surface and inside and affecting the quality and yield. In this work, the effect of quartz-sand addition on the formation of voids in microcrystalline cast stone prepared from blast-furnace slag is studied. The theoretical composition, phase transformation, and microstructure of microcrystalline cast stone are analyzed through FactSage thermodynamic calculations, X-ray diffraction, and scanning electron microscopy. The results show that the main crystal phases in the microcrystalline cast stone are gehlenite and akermanite for 5, 7, 8, and 10 % quartz-sand addition. When the amount of quartz sand added is 8 %, the overall shrinkage rate of the ordinary augite phase is 16 %. The maximum amount of dicalcium silicate is formed, filling the holes on the surface and inside and inhibiting the formation of holes. The crystal morphology is snowflake-like and the crystal connections are dense. The flexural strength reaches a maximum value of 40.08 MPa, which improves the overall performance of the microcrystalline cast stone. The results of this study can provide technical support for improving the yield and quality of microcrystalline cast stone prepared by melting. [Display omitted] [ABSTRACT FROM AUTHOR]

Lanthanum nickel oxide (LaNiO 3, LNO) films exhibit excellent electrical conductivity but poor mechanical properties, considerably limiting their further development in the field of flexible electronics. In this study, flexible LNO thin films of different thicknesses were fabricated on a unique two-dimensional (2D) mica platform using a simple metal organic deposition technique. The obtained LNO films exhibited a pseudocubic phase without impurities. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterisations proved that the films were well-crystallised, dense, and flat, with controllable thickness. In addition, the flexible LNO/mica element possesses low resistivity (5 × 10−4 Ω cm), translucency, and good bending resistance. The electrical resistivity can remain stable under various bending radii (r = 10∼2 mm), thousands of bending cycles, and a wide temperature range (28–200 °C), demonstrating good durability, mechanical stability and temperature resistance. Furthermore, a ferroelectric BiFeO 3 film was constructed based on the obtained conductive LNO electrode, which exhibited typical ferroelectric characteristics. This excellent performance suggests that the flexible LNO electrode is promising for flexible electronic applications. [ABSTRACT FROM AUTHOR]

In this study, the technology important Cu 0.5 Mn 0.5 Fe 2 O 4 and Cu 0.5 Mn 0.5 Fe 1.80 RE 0.2 O 4 (RE = La, Gd, Nd, and Dy) nanoferrites were synthesized via sonochemical method and characterized to overcome the electromagnetic pollution problems. Crystalline, morphological, electrical, magnetic, and microwave-absorbing parameter were identified by doping of RE (La, Gd, Nd, and Dy) in Cu 0.5 Mn 0.5 Fe 2 O 4 nanoferrites. The XRD analysis revealed a cubic spinel structure with a single-phase composition for Cu 0.5 Mn 0.5 Fe 2 O 4 nanoferrites whereas Cu 0.5 Mn 0.5 Fe 1.80 RE 0.2 O 4 (RE = La, Gd, Nd, and Dy) nanoferrites had a cubic structure with the presence of a secondary phase. SEM images confirmed the spherical shape of the particle and the grain size within the range of 19.25–28.19 nm, with elemental stoichiometry confirmed by EDS spectra. The dielectric constant and conductivity of Cu 0.5 Mn 0.5 Fe 1.80 RE 0.2 O 4 nanoferrites were low at higher frequencies, which lead good candidates for microwave-absorbing technologies. The substitution of RE decreases saturation magnetization (43.38–23.96 emu/g) and squareness ratio values of prepared nanoferrites were less than 0.5. The SE T values of the prepared nanoferrites were in the range of 32.31–41.81 dB. The minimal reflection loss (RL) values of Cu 0.5 Mn 0.5 Fe 2 O 4 and Cu 0.5 Mn 0.5 Fe 1.80 RE 0.2 O 4 nanoferrites were less than 10 dB and which indicated that the prepared nanoferrites possessed great potential for applications as microwave-absorbing materials. [Display omitted] • The dielectric properties of Cu 0.5 Mn 0.5 Fe 2 O 4 nanoferrites were enhanced by doping of RE (La, Gd, Nd, and Dy). • Magnetic behaviors of Cu 0.5 Mn 0.5 Fe 2 O 4 were tuned by doping of RE (La, Gd, Nd, and Dy) ions. • The SE T values for the LCMFO, GCMFO, NCMFO, and DCMFO nanoferrites are 41.81, 44.23, 49.24 and 54.92 dB, respectively. • RE (La, Gd, Nd, and Dy) doped nanoferrites showed good RL values (−23.62, −32.57, −39.729, and −45.520 dB) in the X-band frequency. [ABSTRACT FROM AUTHOR]

In this experiment, PrFeO 3 -In 2 O 3 nano-composites were prepared by electrospinning and hydrothermal approach. In particular, the PrFeO 3 -In 2 O 3 material has a rough surface, which can enhance the contact area with the gas, and further analysis shows that the band gap of the PrFeO 3 -In 2 O 3 material is reduced compared with the pure In 2 O 3 material. Compared with pure In 2 O 3 , PrFeO 3 -In 2 O 3 composite has better sensing performance for n-butanol. The results show that the PrFeO 3 -In 2 O 3 based sensor has remarkable gas sensing performance for n-butanol gas. Especially the response to 100 ppm n-butanol is as high as 95.98 at 190 °C, and good repeatability. In addition, the response of PrFeO 3 -In 2 O 3 based sensor shows a good linear relationship with the concentration,n-butanol gas can be quantitatively measured.In this work, X-ray diffraction (XRD), X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), specific surface area testing (BET), and UV–Vis spectroscopy were used to characterize the materials. [ABSTRACT FROM AUTHOR]

Cobalt removal is considered a common method to improve the performance of polycrystalline diamond compact (PDC). To effectively reduce the pollution during the process of cobalt removal, a neutral electrolyte was used in this work to remove cobalt from PDC by electrolysis with ultrasonication. The electrode process and mass transfer model of cobalt removal in a NaCl–KCl solution were established by performing electrochemical impedance spectroscopy (EIS) measurements. Different electrode potentials and electrolytic durations were set to investigate the limits of cobalt removal in the neutral electrolyte. Cobalt removal was assessed by conducting potentiodynamic polarisation, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) measurements. The ImageJ2x image analysis software was used to study the collected spectra. The experimental results indicated that cobalt was successfully removed in the neutral electrolyte and that ultrasonication enhanced its removal. The optimal electrode potential for cobalt removal in the NaCl–KCl solution was less than 500 mV or more than 2000 mV. As the electrolysis time increased, the porosity of the PDC surface first increased to 9.4 % and then decreased to 7.2 %, and the depth of cobalt removal was up to 224 μm. Over time, the rate of cobalt removal decreased, suggesting that the efficacy of ultrasonication in promoting the cobalt removal process gradually weakened as electrolysis products continued to accumulate. [ABSTRACT FROM AUTHOR]

Carbon black has been successfully converted into silicon carbide by reacting it with SiO vapor at 1500 °C under Ar gas environment. The influence of reaction temperature, duration and Ar gas flow rate on the final product was examined. The structural and microstructural property of synthesized SiC was characterized using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Micrographs of synthesized SiC showed that the final product was an agglomeration of SiC nano-powder of 50–500 nm size and nano-whiskers/fibres having a diameter of 50–500 nm and lengths in 0.1–10 μm depending on Ar gas flow rate. The higher conversion of C into SiC was observed at 1500 °C with Ar gas flow rate ∼250 ml/min. [ABSTRACT FROM AUTHOR]

Lithium tantalum phosphate LiTa 2 PO 8 ceramics have attracted significant attention as solid electrolytes in oxide-based all-solid-state batteries owing to their superior bulk conductivity of more than 1 mS cm−1 at room temperature. However, high-temperature sintering at 1050 °C, which is required to achieve a dense morphology, results in a high interfacial resistance at the grain boundaries. In this study, dense LiTa 2 PO 8 ceramics were successfully synthesized via a conventional solid-state method at a low sintering temperature of 900 °C using Bi 2 O 3 as the additive. A total lithium-ion conductivity of 1.41 × 10−3 S cm−1 at 25 °C was achieved. The microstructures of the sintered LiTa 2 PO 8 ceramics were analyzed by X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Large LiTa 2 PO 8 grains grew in the dense solid-electrolyte body together with the interfacial BiPO 4 phase, which acted as a sintering flux material, at a low sintering temperature of 900 °C. Thus, these LiTa 2 PO 8 ceramics can serve as oxide solid electrolytes for all-solid-state lithium batteries owing to their high total Li-ion conductivity. [ABSTRACT FROM AUTHOR]

We describe a low-cost method for the synthesis of reversible thermochromic K 2 O·nSiO 2 -based anti-fire materials with bidirectional responsion and memory function, which was significant for energy-saving and fire-resistant applications. Here, the reversible thermochromic (RTC) and inverted reversible thermochromic (IRTC) K 2 O·nSiO 2 -based anti-fire glass were prepared via an in-situ reaction using a high solid content and low viscosity SiO 2 sol (HSLV SiO 2 sol, 55 wt%). The morphological, thermochromic, thermal insulation, and memory performances were systematically characterized. The pincer-like structure, rod-like structure and the layered microporous morphology were clearly shown in scanning electron microscopy (SEM) micrographs. The color change, foaming, and memory mechanisms were further investigated in detail. The significant differences appeared in the visible region of RTC and IRTC K 2 O·nSiO 2 -based anti-fire glass during heating and cooling process. FTIR spectra were used to characterize the difference among RTC, IRTC and control samples. The results indicated that a small amount of NH 4 + caused the K 2 O·nSiO 2 -based anti-fire glass to exhibit IRTC characteristics, and the continuous addition of polyhydric alcohols was the key to obtain RTC performance. The IRTC K 2 O·nSiO 2 -based anti-fire glass was suitable for the conservatories or greenhouses, and the RTC K 2 O·nSiO 2 -based anti-fire glass reduced the direct sunlight exposure to control the indoor temperature. Combined with morphological and Tg analysis, the thermal insulation performance was enhanced by a microporous insulating layer with a sponge-like structure. We also used the bidirectional reversible thermochromic performance to prepare a novel anti-fire glass component for construction with anti-counterfeiting function. This work provided a new approach for the application of multifunctional smart windows. [ABSTRACT FROM AUTHOR]

ZnS thin films were synthesized using the spray pyrolysis technique at 350 °C. Following the annealing process, X-ray diffraction (XRD) analysis was performed to examine the structural characteristics of the films. This analysis revealed a gradual substitution of sulfur by oxygen during an extended annealing period, leading to the transformation of the samples into a mixed phase consisting of ZnS, ZnO, and a substitutional solid solution Zn(S,O). The surface morphology and elemental composition of the treated films were investigated using Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX) and profilometry. These crystalline particles of growing ZnO phase adopt a hexagonal shape, displaying well defined edges and smoother surfaces, with dimensions of approximately 600 nm. Moreover, a change in surface properties, marked by a transition from hydrophilic to hydrophobic behavior, was observed. The optical characteristics were examined through transmittance, reflectance and absorbance spectra, recorded in the range of 200–2500 nm. Films with a high percentage of ZnO are more absorbent in the UV range and have a narrower bandgap energy. Additionally, the photocatalytic activity was evaluated by monitoring the degradation of an aqueous solution of methylene blue (MB) when exposed to sunlight. Enhanced degradation of MB dye was observed as the amount of zinc oxide in the annealed samples increased. [ABSTRACT FROM AUTHOR]

The fabrication of hydroxyapatite (HAP)/MgO composite coatings on Mg alloy is crucial for enhancing the corrosion resistance and biocompatibility of biomedical implants. In this study, we aimed to investigate the effects of two different surface modification methods, i.e., electrochemical (electrodeposition, ED) and chemical (solution treatment, ST), on the phase structure, degradation properties, and biocompatibility of the composite coatings in comparison to the anodized coating. The surface morphologies and crystalline structures of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Subsequently, the degradation rate of the coatings in simulated body fluid were comprehensively evaluated by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electrochemical microscopy (SECM) tests. Additionally, in-vitro cell proliferation assays were employed to quantitatively assess the biocompatibilities of the coatings. The results showed that both ED and ST methods were effective in depositing HAP on anodized Mg alloy, resulting in different surface morphologies with hydroxyapatite layer thicknesses of 2.71 μm and 3.56 μm, respectively. In this way, the HAP-deposited coatings exhibited improved corrosion resistances and biocompatibilities compared with those of the anodized coating. Specifically, the ST-deposited composite film displayed superior degradability and biocompatibility which was attributed to its filiform surface morphology and thicker HAP layer. Overall, the present study demonstrates the potential of HAP/MgO composite coatings for biomedical applications, with implications for the development of advanced implant materials with improved performance and biocompatibility. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have a wide range of applications in energy storage power stations. However, thermal runaway of LIBs can lead to serious safety accidents and cause significant losses. Therefore, it is particularly important to carry out early security warning of LIBs. And H 2 is generated along with the growth of lithium dendrites, which can serve as an effective indicator for detecting LIBs before TR. In this paper, In 2 O 3 /NiO nanocomposites were prepared, and five groups of samples were systematically prepared by adjusting the molar ratio of In and Ni. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and other test methods were used to characterize the prepared nanocomposites. Through experiments, the best samples among several groups of samples were determined. When the test gas is introduced, the resistance change of this optimal sensor is the greatest, indicating the best performance, which is significantly better than pure In 2 O 3 and pure NiO samples. Furthermore, compared to other gases, this nanocomposite sensor exhibits significant selectivity towards H 2. The results show that In 2 O 3 /NiO is a promising candidate material for room temperature H 2 detection, and provide suggestions for the development of gas sensors with heterogeneous structures. [ABSTRACT FROM AUTHOR]

Two experimental ceramic systems, 3Y-TZP/5Y-PSZ (3Y/5Y) and 4Y-PSZ/5Y-PSZ (4Y/5Y), underwent analysis before (3Y/5Yi or 4Y/5Yi) and after hydrothermal aging (3Y/5Ya or 4Y/5Ya) to simulate low-temperature degradation (LTD). The samples were sintered and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy, alongside nanoindentation tests to measure elastic modulus (Em) and hardness (H). Assessments were conducted on the external surfaces and at individual layers on cross-sectioned samples at predetermined regions of interest (ROIs). Degraded superficial regions were observed in the cross-sectional SEM images of the 3Y and 4Y zirconia layers after aging. XRD indicated a tetragonal→monoclinic phase transformation in the aged groups for both 3Y (66 % m-ZrO 2) and 4Y (29 % m-ZrO 2). Raman spectroscopy revealed monoclinic phase amounts of 86 % for 3Y and 62 % for 4Y in the degradation regions observed in the SEM micrographs. Monoclinic phase peaks were virtually no longer detected in either material beyond a depth of 15 μm. Hydrothermal aging significantly diminished the H and Em values for the 3Y and 4Y zirconia surfaces. For the analysis of different zirconia surfaces within the same subgroup, all pairwise comparisons showed statistically significant differences, except for the values of H of 3Y/5Yi and Em for 4Y/5Yi. Regarding the nanoindentation results of cross-sectioned samples, the aging protocol did not affect the H and Em values of the equivalent ROIs (layers), regardless of the bilayered system. However, significant differences in H values were observed among the ROIs (layers) within the same bilayered system. Despite surface changes, nanomechanical properties remained preserved below the surface and at the interfaces of bilayered materials after aging. Nanoscale H values varied among some layers and interfaces, whereas the Em values exhibited differences across certain surfaces. [ABSTRACT FROM AUTHOR]

The fragmentation behavior of mixed diamond particles with different grain sizes under high pressure is important to guide the design of raw material diamond powder ratios and obtain high performance polycrystalline diamond compact (PDC). In this study, five different grain size diamond powders commonly used for the preparation of PDCs were selected, and the single and mixed diamond particles were cold pressed at 7.7 GPa for 60s. The particle size variations of diamond powders with different principal particle sizes and ratios after cold pressing were analyzed by a laser particle size scanner, and the crushing behavior was observed by scanning electron microscopy. The results showed that the larger the initial grain size, the more significant the degree of fragmentation under high pressure. The crushing morphology of fine-grained diamond showed that the majority of grains were locally fractured at the edge, and the peak of the grain size distribution curve was shifted to the left after high pressure. In comparison, the coarse-grained diamond produced a large number of cracks and fractures along the weak grain boundaries under high pressure, which generated a large number of fine grains, and multiple secondary peaks in the particle size distribution curve. The addition of fine-grained diamond as filler particles to coarse-grained diamond could inhibit the crushing phenomenon to some extent. As the proportion of filler particles increased, the crushing of coarse-grained diamond was inhibited more significantly. When the proportion of filler particles was 30 wt%, the crushing under high pressure was greatly limited, especially when the size difference between filler particles and main particles was large. The results of the cold pressing experiments provided preliminary evidence that 30 wt% of filler particles were too high, and that a better ratio should be between 10 wt% and 20 wt%. [ABSTRACT FROM AUTHOR]

This paper presents the results of the combined study of the thermoluminescence (TL) and electron paramagnetic resonance (EPR) properties of La-doped CaF 2 (CaF 2 : La) phosphor. X-ray diffraction (XRD) results confirmed that CaF 2 has been successfully synthesized. Scanning electron microscopy (SEM) results and energy dispersive spectrometer (EDS) spectra show that the synthesized phosphor is pure and has a good overall morphology. The glow curve of CaF 2 : La phosphor shows an emission band between 230 and 500 nm centered at 340 nm. The Tm-Tstop method and the deconvolution technique were used to find the number of overlapping TL peaks in the 50–300 °C region and their kinetic parameters. A linear dose-response curve was obtained for the range 1–9 Gy, with the onset of a slight supralinear behavior for doses higher than 9 Gy. Gamma-irradiated CaF 2 : La phosphor has been studied using the technique of EPR to identify the defect centers and also to infer the centers involved in the TL process. Thermal annealing studies indicate the presence of three defect centers. One of the centers (center I) is identified as the O 2 − ion and is characterized by an axial g -tensor with principal values g ∥ = 2.013 and g ⊥ = 2.0053. This center correlates with the TL peak at 200 °C. Center II with an isotropic g -value of 2.0005 is attributed to an F center and also relates to the 200 °C TL peak. The third center (center III) is assigned to an F center. [ABSTRACT FROM AUTHOR]

Batteries can be overdischarged in practical applications, which does not pose safety risks. However, overdischarge can have a significant impact on battery performance. In this work, LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM)&LiMn 2 O 4 (LMO)/graphite batteries are used as the main body. The failure mechanism of the batteries under different temperatures (−10 °C, 25 °C, 45 °C) and different depth of discharge (DOD) (105 % DOD and 110 % DOD) is studied systematically through the electrochemical methods, scanning electron microscopy (SEM), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that the deep overdischarge and high temperature accelerate the degradation of electrolyte, separator and collector, and cause rupture and recombination of solid electrolyte interphase (SEI) film. These result in the loss of conductivity, active substances and lithium ions, in which the loss of lithium ions plays a dominant role. Moreover, the attenuation of positive active material mainly comes from NCM. Our research results are of great significance for researchers to understand the failure mechanism of lithium batteries under different conditions and can provide important guidance for the safe design of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

A recent study delves into the enhancement of supercapacitors to increase their energy density while maintaining fast charge-discharge capabilities and longevity. This is achieved by developing electrode materials with improved conductivity and carefully designed nanostructures to overcome the limitations of pseudocapacitors. The study highlights MnCo 2 S 4 for its impressive specific capacitance and cost-effectiveness. It elucidates the synergistic interactions and charge transfer dynamics between manganese (Mn) and cobalt (Co), which significantly enhance electrochemical performance. A new one-step hydrothermal synthesis method is presented for producing MnCo 2 S 4 nanogranules directly on a nickel foam substrate, eliminating the need for binders and achieving an optimized morphology that boosts electrochemical activity. Through a thorough analysis involving X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM) along with cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), the study comprehensively characterizes the structural, morphological, and electrochemical properties of MnCo 2 S 4. The synthesized MnCo 2 S 4 electrode exhibited an outstanding capacitance of 6375 mF/cm2 at a current density of 25 mA/cm2. This exceptional performance is mainly attributed to its well-designed 3-D nanogranular structure, which not only enhances the accessibility of electrolyte ions to active sites, thus improving electrochemical reactivity and capacitive utilization, but also utilizes the synergistic interaction between manganese and cobalt. This synergy promotes enhanced redox reactions and stability, resulting in a higher specific capacitance and energy density. These results highlight the crucial role of advanced electrode material development and creative synthesis methods in advancing supercapacitors as a viable energy storage solution, demonstrating the groundbreaking potential of MnCo 2 S 4 in electrochemical energy storage progress. [Display omitted] [ABSTRACT FROM AUTHOR]

A long-term foundational study aimed at developing a thermodynamic database for continuous basalt fiber systems is in progress. In this work, the equilibrium phase relations of the SiO 2 –Al 2 O 3 –Fe 3 O 4 -5 wt.% CaO system at 1400 °C in air atmosphere were determined experimentally using the equilibrium-quenching technique. Subsequent analyses were conducted using Electron Probe Micro-Analysis (EPMA), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) to validate the experimental results and further investigate the microstructural characteristics. The results revealed a single liquid region and three distinct two-phase regions as Liquid-Cristobalite, Liquid-Mullite solid solution, and Liquid-Spinel solid solution. Additionally, two three-phase regions were identified as liquid-cristobalite-mullite solid solution, and liquid-mullite solid solution-spinel solid solution. This work contributes to a deeper understanding of the phase behavior during the melting of basalt ore systems, which is crucial for optimizing their production and enhancing their applications. [ABSTRACT FROM AUTHOR]

In the current study, the effect of Cr 2 O 3 on the break temperature and crystallization behavior of Cr-containing molten titanium slag was investigated. The type, composition, and morphology of crystallized phase were analyzed by FactSage, X-ray diffraction (XRD), and scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS). It was found that the break temperature (T Br) of Cr-containing molten titanium slag tended to increase with the increase of Cr 2 O 3 content. When the Cr 2 O 3 content was 4 wt%, the T Br was 1470 °C. With the increase of Cr 2 O 3 content, the Ti-containing phase began to appear at the temperature above the T Br. Moreover, the main crystallized phase that existed at the temperature below the T Br transformed from only anosovite to both anosovite and spinel, indicating that Cr 2 O 3 promoted the precipitation of spinel. The rapid increase in viscosity was mainly determined by the precipitation of anosovite in the slag without Cr 2 O 3. When the Cr 2 O 3 content was 2 wt%, the increased precipitation amount of Ti-containing phase caused the abrupt change in viscosity. As the Cr 2 O 3 content further increased to 4 wt%, the precipitation amounts of anosovite and spinel significant increased, which resulted in the sudden increase in viscosity. This study could provide theoretical support for the comprehensive utilization of Cr-containing molten titanium slag and sustainable development of titanium and chromium resources. [ABSTRACT FROM AUTHOR]