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Compatible nanoparticle properties in photocatalytic applications are crucial. Within the scope of this investigation, we constructed a nanocomposite of ZnO and CuCo 2 O 4 (ZnO/CuCo 2 O 4) to boost the photocatalytic properties of ZnO by constructing ZnO/CuCo 2 O 4 nanocomposite using Artocarpus altili s leaves extracts (AALE). Essential secondary metabolites contribute to the origin of weak bases and capping agents to form the spherical shape of ZnO/CuCo 2 O 4. X-ray diffractometry (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy, ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscope - energy dispersive X-ray spectroscopy (SEM-EDX) are some of the techniques that are utilized for the validation of nanocomposite properties, such as vibrational, crystallinity, band gap, morphology, particle size, and elemental composition. The formation of ZnO/CuCo 2 O 4 decreased the bandgap energy and enhanced the photocatalytic performance by 93.01 % under visible light irradiation for 2 h. ZnO/CuCo 2 O 4 followed pseudo-second-order kinetic in the photodegradation of malachite green (MG). It is noted that the increase in photocatalytic characteristics can be brought about by the narrower band gap of ZnO and increased kinetic rate toward dye degradation. Radical species analysis was of utmost importance in acknowledging that holes (h+) were the most crucial species that were indispensable to MG degradation. The photodegradation efficiency of the recycled catalyst only declines by approximately 12 % after five cycles of consumption. This study demonstrates a compelling method using plant extracts to prepare visible-light response ZnO-based nanocomposites for better photocatalytic activity and stability. [ABSTRACT FROM AUTHOR]

Orthorhombic stable phase of MoO 3 and Ni-doped MoO 3 with different weight percentages (2 %,5 % and 10 %) were successfully synthesized by following a surfactant free acid-assisted chemical co-precipitation method under optimized experimental conditions. Structural and compositional investigation using tools like X-ray diffraction and Raman spectroscopy verified the orthorhombic phase and structure quality of the prepared samples with findings from Raman consistent with those from XRD. The optical characteristics analysed using UV–Vis diffused reflectance spectroscopy and photoluminescence spectroscopy revealed that Ni2+ may act as a shallow acceptor at lower doping concentrations. It was observed that the structure and characteristics of MoO 3 dramatically altered as a function of Ni doping concentration, suggesting that Ni ions migrated from lattice substitution to grain boundaries. Images from field emission scanning electron microscope revealed the formation of layer-by-layer growth of micro-plate like morphology of the prepared samples with increasing agglomeration influenced by grain boundaries. EDAX spectrum confirmed the presence of Mo, O and Ni and their compositional proportion. Based on the properties analysed, the photocatalytic properties of the synthesized samples were analysed for degradation of Alizarin Red dye and kinetic studies were conducted. The optical characterization revealed defect induced emissions and the feasibility of MoO 3 acting as a photodetector was studied along with Ni-doping proving the versatility of material for multifunctional applications. [ABSTRACT FROM AUTHOR]

Mullite ceramic membrane is considered as microfiltration membrane suitable for oil-water (O/W) emulsion wastewater treatment. This study presented a facile sintering approach to prepare mullite ceramic membrane from coal fly ash. Various characterization techniques, such as X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), shrinkage and apparent porosity, bending strength etc. were used to reveal the effect of MoO 3 addition and sintering temperature on ceramic membrane. At sintering temperature 1300 °C, adding 5 wt% MoO 3 , the apparent porosity of membrane is 46.04%, the bending strength is 32.11 MPa, and the average pore size is 0.190 μm. Finally, whisker mullite ceramic membranes were applied for deep treatment of oily wastewater. As-synthesized ceramic membrane exhibits excellent permeate flux (391.10 L·m−2·h−1) and oil rejection (97%) for separation of O/W emulsion. The membrane fouling is mainly controlled by cake filtration mechanism. Meanwhile, the ceramic membranes show good regeneration performance and acid and alkali resistance. This study provides theoretical and technical support for preparation of whisker mullite ceramic membranes from fly ash and deep treatment of oily wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we present the fabrication of large single-domain ternary (Sm,Eu,Gd)Ba 2 Cu 3 O 7-y bulk superconductor with enhanced superconducting properties using various REBa 2 Cu 3 O y (RE-123) as a liquid source via the top-seeded infiltration growth process (TSIG) in air. We employed a 1:1 ratio of REBa 2 Cu 3 O y (RE = Sm, Gd, Y and Er) and Ba 3 Cu 5 O 8 as a liquid source for fabrication. Impressively, all the obtained bulk samples exhibited a superconducting transition temperature T (c, onset) above 94 K. However, the bulk sample fabricated using Y-123 + Ba 3 Cu 5 O 8 as a liquid source demonstrated a T (c, onset) of 94.53 K, with a 40.14 % improvement in transition width (Δ T c) and at 77 K the bulk recorded a self-field critical current density (J c) value of 44.73 kA/cm2 & 10.62 kA/cm2 at 1T resulting in a remarkable 93.08 % improvement in self-field J c compared to the bulk sample fabricated using Er-123 + Ba 3 Cu 5 O 8. Microstructural analysis using a scanning electron microscope revealed a significant reduction in the mean size of secondary (211) phase particles, a significant reduction of 38.41 % is observed for the Y-123 + Ba 3 Cu 5 O 8 employed sample. [ABSTRACT FROM AUTHOR]

The solubility/degradability of bioactive glasses play crucial role in bone tissue engineering applications owing to the release of ions from their structure, which exert therapeutic effects on tissues. The present study evaluates the findings of a detailed investigation on the main features and solubility behaviors of newly formulated Nb incorporated glasses (Nb-BGs). New glass formulation in SiO 2 –CaO–Na 2 O–P 2 O 5 –CaF 2 –SrO–xNb 2 O 5 (x: 0.0, 0.5, 1.0, and 1.5 mol. %) system was successfully synthesized by melt-quenching technique. Glass composition was verified with Energy Dispersive X-ray Fluorescence spectrometer analysis and its amorphous nature, functional groups of the matrix and morphological features were identified via X-Ray diffraction analyses, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscope analysis, respectively. Network connectivity (NC) of the Nb-BGs was assessed with respect to the role of Nb 2 O 5 in the glass matrix as network former, modifier, or both. In order to evaluate the in vitro solubility of Nb-BGs, released concentrations of particular ions from the glass compositions were determined at certain time points and comprehensively discussed with several mathematical models such as zero-order, first-order, second-order, Higuchi, and Korsmeyer-Peppas for the first time. Results showed that the incorporation of Nb 2 O 5 (up to 1.5 mol. %) increased the density, oxygen density as well as NC values of newly formulated glasses. Si, Na and Ca ions which play a main role in well-defined Hench's mechanism followed mostly second-order release kinetics for all glasses in the mathematical models studied. When the Nb content increase (to 1.5 mol. %) in glass composition, the release mechanism of Si ion according to Korsmeyer-Peppas model shifts from the diffusion mechanism to an erosion-dominant release mechanism. [Display omitted] [ABSTRACT FROM AUTHOR]

The crystal structure of La 0.7 Sr 0.3 Mn 1−x Al x O 3 (LSMAO) with x = 0,0.025,0.05,0.075 and 0.10 ceramics prepared by the Sol-gel method were investigated by employing the XRD technique. The XRD patterns analysis by employing the Rietveld analysis confirms the nonexistence of secondary crystal phase/s and, materials are crystallized to the R-3c(167) space group. The microstructural properties were studied using scanning electron microscope (SEM) and transmission electron microscope (TEM). The dielectric property, AC conductivity, complex impedance spectroscopy and complex electrical modulus have been studied over a wide range of frequencies (103 Hz–107 Hz) at different temperatures from 313K to 393K. The Non-Debye type relaxation process has been observed in synthesized samples confirmed from the Nyquist plot. The Cole-Cole plots were employed to estimate the individual grain and grain boundary contributions. The Maxwell-Wagner (MW) polarization model provides an explanation for the greater values of dielectric constant at the lower frequencies. The present study explores the technological usefulness of LSMAO. [ABSTRACT FROM AUTHOR]

This study centers on the synthesis and characterization of a novel double perovskite, termed Sr 2 TiZrO 6 (STZO), which was synthesized using the conventional solid-state reaction method and subsequently calcined at 1000 °C for 12 h. X-ray diffraction (XRD) pattern refinement confirmed the formation of the tetragonal phase Sr 2 TiZrO 6 (space group P 4 mm), while both XRD and scanning electron microscope (SEM) analyses revealed that the resulting STZO displaying spherical-like grains with nanometric diameters. Thermogravimetric analysis revealed a minor weight loss attributed to the emergence of the ZrO 2 phase and the formation of the STZO double perovskite. The diffuse reflectance spectroscopy (DRS) results demonstrated strong UV-light absorption, with an optical absorption onset below 400 nm. The obtained band gap for direct transitions of the STZO sample is equal to 3.26 eV. The conductance and impedance study of the STZO sample are investigated. The present properties provide crucial insights to enhance comprehension of the STZO double perovskite material, which holds promise as a viable candidate for a range of applications, such as solar cells and photodiodes. [ABSTRACT FROM AUTHOR]

Previously, a strategy for doping MIEC perovskites ABO 3-δ with highly charged cations B5+ (Nb, Ta) and B6+ (Mo, W) was developed. The doping strategy is based on the idea that strontium ferrite/cobaltite-based perovskites are ferroelastic, whereas highly charged cations are ferroactive species. An increase in the concentration of the dopant leads to a reduction in the size of the domains of the ferroelastic phase down to the nanoscale. This resulted in the smearing of phase transitions with the formation of the highly conductive glassy state. Tantalum-doped lanthanum-strontium-ferrite perovskite (La 0.6 Sr 0.4 Fe 1-x Ta x O 3-δ , LSFTx) was prepared via solid-state reaction using chemically pure oxide powders of La 2 O 3 , SrCO 3 , Fe 2 O 3 , and Ta 2 O 5 , followed by calcination and sintering up to 1350 °C. The structural and surface properties were examined using X-ray diffraction and a scanning electron microscope. The original oxygen partial pressure relaxation (OPPR) method was used to study the kinetic properties of LSFTx. Continuous equilibrium phase diagram "T – pO 2 – δ" first obtained by oxygen release technique for composition LSFT3.5. Power law dependencies of the kinetic properties on the oxygen partial pressure are presented. [ABSTRACT FROM AUTHOR]

Additive manufacturing of components with enhanced characteristics to combine the geometrical flexibility of layer-by-layer manufacturing and the remarkable thermomechanical and optical properties of advanced materials has become a focus for research in the last decades. In this investigation, in-house developed Al 2 O 3 slurries mixed with either MgO or MgAl 2 O 4 were digitally light processed and the resulting green parts underwent slow thermal debinding at low heating rates to produce dense and stable brown samples, which were subsequently subjected to different sintering regimes to obtain translucent samples. Air sintering trials were conducted at 1700 °C and the effect of different heating rates and holding times at the sintering temperature were investigated. In addition, vacuum sintering at 1600 °C was conducted for the best conditions to assess the effect of an oxygen-reduced atmosphere. Geometrical dimensions and density data were collected at the brown and fired stages to observe their evolution through the process with the help of high-magnification optical microscopy. Scanning electron microscope (SEM) images of the sintered samples were collected to observe and characterise the obtained microstructure. In addition, X-ray diffraction (XRD) was used to identify the crystal structure and assess the insurgence of secondary phases. Finally, total transmittance and in-line transmittance were measured to evaluate the translucency level achieved by the produced sintered samples. Translucent alumina samples exhibiting a maximum total transmittance of 90.4% and a maximum real in-line transmittance (RIT) of 16.9% in the visible and near-infrared regions were fabricated. [ABSTRACT FROM AUTHOR]

NiSi–NiCr thin film thermocouples (TFTCs) have significant application value as contact temperature sensors in cutting temperature measurements owing to their fast response and negligible volume. However, due to the relatively high chemical activity of Ni-based alloys, high-temperature oxidation strongly affects the operational reliability of NiSi–NiCr TFTCs. In this respect, depositing an anti-oxidation coating onto the surface of NiSi–NiCr TFTCs is considered an effective way to protect them in high-temperature environments. In this study, NiSi and NiCr films were deposited on cemented carbides and annealed at 200 °C–600 °C in air. Scanning electron microscope, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and four-probe resistivity tests were used to characterize the microstructure and resistivity of NiSi and NiCr film. Then SiN x O y films were deposited onto the NiSi and NiCr films and compared with uncoated samples after annealing at 600 °C. The effect of SiN x O y films on the thermal stability and thermoelectric output of NiSi–NiCr TFTCs was investigated. The results show that the NiSi film was partially oxidized at 200 °C and entirely oxidized when the temperature exceeded 400 °C. The completely oxidized NiSi films had evident defects and cracks, and the resistivity increased by a factor of over 1000. The NiCr film could not be completely oxidized at 600 °C, which is attributed to the formation of Cr 2 O 3 as an external oxide barrier layer. Below 600 °C, SiN x O y films could effectively protect NiSi and NiCr films from oxidation. Thus, the addition of SiN x O y film increases the maximum temperature at which NiSi–NiCr TFTCs can be used. [ABSTRACT FROM AUTHOR]

This work's main objective is to assess the effects of wollastonite/fluorapatite glass (G) and glass-ceramic (GC) on tricalcium silicate's (TCS) bioactivity and physico-mechanical properties. To achieve this goal, 10 and 20 wt percent of G or GC were used in place of TCS. The constructed specimens were kept submerged in SBF solution for 4 weeks at a temperature of approximately 37 ± 0.5 °C to create the hydroxyapatite layer (HA) on the cement paste surface and evaluate their biological behavior. Additionally measured were bulk density, apparent porosity, and compressive strength. The principal components had been studied using X-ray diffraction and Fourier transform infrared spectroscopy. An energy dispersive spectroscopy (EDS)-equipped scanning electron microscope (SEM) was used to examine the materials' morphology. The antibacterial and cytotoxic properties were also evaluated. The findings demonstrated that during soaking in SBF, bulk density and porosity ranged from 1.38 to 1.5 g/cm3 and from 44.99 to 39.12 %, respectively, and the results for compression strength varied from 65 to 88 MPa. The outcomes demonstrated that all of the prepared samples' surfaces had the hydroxyapatite layer (HA) formed on them following their immersion in the biological fluid (SBF). Additionally, it was discovered that raising the percentage of GC (TCS/20GC) in synthetic samples improves TCS cement's physico-mechanical and bioactivity characteristics. Furthermore, these substances had minimal cytotoxic effects on the typical fibroplast cell line of humans (BJ1), indicating their potential utility in dental applications. Ultimately, the antimicrobial test demonstrated good inhibitory behavior against the pathogens Bacillus cereus, Staphylococcus aureus, and Pseudomonas aeruginosa. [ABSTRACT FROM AUTHOR]

This work aims to modify the surface characteristics of cerium oxide (ceria, CeO 2) nanoparticles using different surface modification strategies for improved CeO 2 nanoparticle dispersion and suspension stability. Analysis and discussion were conducted on the two surface modification processes used by a cationic surfactant like hexadecyl cetyltrimethylammonium bromide (CTAB) and a silane agent like tetraethyl orthosilicate (TEOS). Untreated CeO 2 was used as reference material. The dispersion effect of surface-modified CeO 2 nanoparticles at different pHs was determined by zeta potential measurements. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Particle size analysis (PSA), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Brunauer–Emmett–Teller analysis (BET), and X-ray diffraction (XRD) were used to confirm the efficacy of the surface modification of CeO 2 nanoparticles. First, the results obtained in this experimental work demonstrate that both advanced modifications greatly enhance the dispersion and suspension stability of surface-modified CeO 2 nanoparticles in comparison with untreated CeO 2 nanoparticles. Second, it is also shown that the surface-modified CeO 2 nanoparticles obtained through a silanization surface process with TEOS silane agent had a better dispersion effect and dispersion stability than the surface-modified CeO 2 nanoparticles obtained by surface modification with CTAB cationic surfactant. These results can help better understand how advanced surface modifications can assist the application of well-dispersed CeO 2 nanoparticles in technological applications. [Display omitted] • Surface modification significantly improved the aqueous dispersion and stability of CeO 2 nanoparticles. • The modification improved the CeO 2 dispersion by increasing the spacing and negative charge. • CeO2 dispersion was optimal at a specific pH, with a significant effect of pH. • The modification strategy is crucial for the performance of CeO 2 in technological applications. [ABSTRACT FROM AUTHOR]

Ni 1-x Ag x O nanoparticles (NPs) with x = 0.00, 0.02, 0.04, 0.06, and 0.08) were fabricated using the composite hydroxide mediated (CHM) method. The effects of Ag doping on the structural, magnetic, and antimicrobial characteristics of NiO NPs have been reported. The stretching mode of the Ni–O molecules was identified at 443 cm−1 in the Fourier transform infrared spectra. The aggregation of nanoparticles with different sizes and shapes is seen under transmission and scanning electron microscopes. The blocking temperature (T B) peak in zero-field cooled (ZFC) magnetization curves display the magnetization from the core of NPs. This peak is absent for the samples with x = 0.00 and 0.02 , which show instead a small net magnetization from the antiferromagnetic core of these NPs. However, a T B peak was found for the samples with x = 0.04 , 0.06 and 0.08 , at 22, 72, and 65 K, respectively, which indicates that the magnetization is induced from the AFM core of NiO NPs for higher Ag doping. With an increasing concentration of Ag in the NiO NPs, the net magnetization did increase and a maximum was found for x = 0.04 at 300 K. For a higher doping concentration of 8 % Ag, a sharp decrease in magnetization was observed. Furthermore, the efficacy and synergistic effect of Ag doping had been analyzed for the effective improvement of the antibacterial properties of NiO NPs. Pure and Ag-doped NiO NPs were exploited to assess their anti-microbial activity against Enterobacter sp., E. coli, P. aeruginosa, and S. pyrogens. The study revealed that anti-bacterial or anti-biofouling properties were introduced as an additional attribute to NiO NPs by incorporation of Ag ions due to its inherent nature as an antimicrobial agent and enhanced its capability to sterilize microbial pathogens. [ABSTRACT FROM AUTHOR]

Lanthanum Strontium Cobalt Ferrite Oxide (LaSrCoFeO 3) has been widely used as cathode material for intermediate-temperature solid oxide fuel cells at the temperature of 500–800 °C. At this temperature range, understanding the electrochemical behavior which is commonly analyzed by complex nonlinear least-squares (CNLS) analysis is very crucial in improving the cathode's performance. However, this analysis shows some limitations in interpreting the electrochemical processes in detail, particularly at the electrode-electrolyte interface. Hence, this study is conducted to compare the electrochemical impedance data analyses by CNLS and the distribution of relaxation times (DRT) of a fabricated LaSrCoFe|BCZY|LaSrCoFe (LaSrCoFe La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 and BCZY=BaCe 0.54 Zr 0.36 Y 0.1 O 2.95) symmetrical cell. Impedance data of the cell is collected at T = 800 °C at two different stabilization times and to further enhance the analysis process, the impedance data of the cell at measurement temperatures of 700 °C and 750 °C are also included. In a Nyquist plot, the cell exhibits depressed semi-circles that represent a few processes occurring at the interface. The DRT analysis is more precise and easily reveals the semi-circles consisting of four different sub-processes (represented by four peaks) than CNLS (represented by four impedance arcs). The extracted responses from both analyses correspond to the oxygen reduction reactions that follow the Adler-Lane-Steele model. The stabilized symmetrical cells for respective 34 h and 17 h show an area-specific resistance (ASR) of (i) 0.22 Ωcm2 and 0.30 Ωcm2 (by CNLS) and (ii) 0.20 Ωcm2 and 0.26 Ωcm2 (by DRT). In addition, the ASR of the cell at T = 700 °C and T = 750 °C after being stabilized for 34 h is (iii) 0.71 Ωcm2 and 0.40 Ωcm2 (by CNLS) and (iv) 0.70 Ωcm2 and 0.44 Ωcm2 (by DRT), accordingly. Conversely, the cell's microstructure is not affected by the applied stabilization periods as observed by a scanning electron microscope. [Display omitted] • DRT analysis predominantly expresses P 1 , P 2 , P 3 and P 4 cathode sub-processes. • The 34 h stabilization period is sufficient to stabilize a 25-mm PCFC button cell. • ASR value of the S34 is lower than S17 according to DRT and CNLS analysis. • Shorter relaxation time means a faster kinetic reaction of electrochemical processes. [ABSTRACT FROM AUTHOR]

Steel slag-based glass ceramic for thermal energy storage was first fabricated by quenching method, and then their high temperature corrosion behavior in the eutectic carbonates and related mechanism have been investigated using X-ray diffraction，Raman spectroscopy and scanning electron microscope techniques. The results show that holding time has a significant influence on the corrosion layer thickness at 800oC. As the holding time was extended, the thickness of the corrosion layer with obvious cracks tended to increase. Further EDS analyses disclosed that the divided corrosive layers along the extended directions of the cracks should be similar in both the compositions and microstructure. Based on these observations, the possible corrosion mechanism was discussed after defining phase structure of nonstoichiometric (Fe 0.35 Al 0.20 Mg 0.44) Ca 0.96 (Fe 0.08 Si 0.70 Al 0.20) 2 O 6.12 as a combined system of CaMgSi 2 O 6 (Di)-CaFe3+AlSiO 6 (Es)-CaAl 2 Si 2 O 8 (An). Oxygen offered by the molten carbonates salt is regarded to play a critical role in the corrosion process. In an atmosphere rich in oxygen, both Na+ and K+ ions diffused into the diopside can replace Ca2+ and Mg2+, etc. resulting in polyhedral structural reorganization for electrical neutrality. On the other hand, the bonding stability of the cation-oxygen bonds in diopside was proved to be weaker than that in single oxides. These two aspects contribute to the continuous dissolution of Ca2+ and Mg2+, etc. in the molten carbonates salt. [ABSTRACT FROM AUTHOR]

Smart windows can benefit from the use of photochromic wooden materials. In the current study, we report the preparation of fluorescent wood that can switch color under visible and ultraviolet lighting conditions. In order to develop a transparent wood that is both fluorescent and photochromic, a mixture of europium and dysprosium activated strontium aluminum oxide (EDSA) nanoparticles (NPs; 8–13 nm) and room-temperature vulcanizing (RTV) silicone rubber (Polysiloxane) was integrated into a delignified wood. EDSA is known for its excellent photostability and thermal stability. The EDSA phosphor has to be efficiently dispersed in RTV to avoid the formation of aggregates, allowing for a better fabrication of colorless wood. The coloration findings from the CIE Lab parameters displayed that when illuminated with ultraviolet rays, this colorless wooden substrate turned green. Using a transmission electron microscope (TEM), the morphological properties of the synthesized EDSA NPs were examined. Various analysis techniques, including elemental mapping, energy-dispersive X-ray (EDX), X-ray fluorescence spectroscopic analyzer (WDXRF), scanning electron microscope (SEM), hardness testing, and photoluminescence spectra, were employed to study the photochromic woods. An absorption band (365 nm) and two emission bands (436 nm and 518 nm) were determined for the prepared photoluminescent woods. When increasing the EDSA content, the results showed that the produced EDSA-infiltrated wood was more water-resistant and highly protective against UV radiation. Reversible photochromic responsiveness to UV light was observed for the prepared transparent luminous wood without fatigue. [ABSTRACT FROM AUTHOR]

The LiVO 3 ultra-low temperature cofired ceramic (ULTCC) was synthesized by the solid-state chemical method and its crystal structure, sintering behavior, and microwave dielectric performances were systematically studied by X-ray diffractometer (XRD) and Scanning electron microscope (SEM). XRD showed that LiVO 3 were pure monoclinic single phase with a space group of C2/c. Furthermore, the best microwave dielectric properties Q × f = 16,900 ± 720 GHz, ε r = 8.78 ± 0.06, and τ f = − 117 ± 2.3 ppm/°C could be obtained when LiVO 3 sintered at optimal sintering condition 520 °C/8 h affirmed by SEM. The microwave dielectric properties were also deeply investigated utilizing the P–V–L chemical bond theory. The microwave dielectric performances of LiVO 3 had a great closer relationship with the V(1)–O bonds explained by analysis data. The low permittivity LiVO 3 with attractive features highlighted it to be a good candidate for ULTCC applications. [ABSTRACT FROM AUTHOR]

Optical diamond materials are essential for infrared optical windows, microwave windows, and laser windows due to their exceptional properties. However, dark features inside the diamond are significant factors limiting optical properties, particularly at high deposition rates. This work focuses on adjusting crystallographic parameters to prepare (110) oriented optical-grade polycrystalline diamond films, aiming to mitigate dark features. Diamond films deposited via microwave plasma chemical vapor deposition (MPCVD) exhibit discernible quality stratification. Characterization analysis of diamond film samples with varying levels of black defects reveals a correlation: films with higher dark feature content tend to exhibit a preference for the (111) orientation, accompanied by a significant presence of penetration twins and interstitial voids. Conversely, transparent diamond films demonstrate a prominent (110) orientation, featuring numerous contact twins that alleviate competition from penetration twins and original grains during growth. Electron backscatter diffraction (EBSD) and scanning electron microscope (SEM) results reveal that transparent diamond films cultivated with a pronounced preference for the (110) orientation manifest consistent and seamless contact twins, leading to fewer dark features and improved optical transmittance. In contrast, (111) oriented diamond film exhibits numerous penetration twins, and holes form between them. Based on the analysis, 5-inch optical polycrystalline diamond films with (110) orientation were achieved successfully by suppressing dark features. [ABSTRACT FROM AUTHOR]

This study investigates the magnetic response of Ho3+ doped Ni 0.4 Cu 0.6 Ho y Fe 2-y O 4 (y = 0.0, 0.02, 0.04, 0.06, and 0.08) spinel ferrites (SFs) and their correlation with crystallite size. The synthesis was achieved using a sol-gel auto-combustion (SGAC) route and performed different characterizations, including X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive x-ray (EDX), Inductively coupled plasma atomic emission spectroscopy (ICP-AES), and vibrating sample magnetometer (VSM) analysis. The cubic spinel phase was verified via XRD in pure NCF and Ho3+ doped NCF samples. The lattice constant (a) was improved from 8.344 Å to 8.378 Å. The substitution of Ho3+ ions led to a decrease in porosity from 42.22 % to 39.54 %. The introduction of Ho3+ ions also reduced the crystallite size (D) from 37.05 nm to 27.72 nm. The specific surface area (S) was increased from 27.44 g/cm2 to 36.14 g/cm2 with the doping of Ho3+. The average particle size (D S) was decreased from 54 nm to 35 nm. The EDX and ICP-AES analyses confirmed the good agreement with the theoretical composition. The VSM measurements provided insights into their magnetic properties. Furthermore, the doping of Ho3+ ions enhanced coercivity (H C), while reducing saturation magnetization (M S) from 64.35 emu/g to 16.22 emu/g. The decrease in crystalline anisotropy (K) observed at higher concentrations of Ho3+ may result from the increase in coercivity, potentially attributable to the smaller crystallite size of the single-domain SFs particles. The single-phase matrix and their magnetic behaviour showed that the Ho3+ doped Ni–Cu SFs samples are suitable for high-frequency applications. [Display omitted] • Ni 0.4 Cu 0.6 Ho y Fe 2-y O 4 was prepared via the sol-gel auto-combustion technique. • The crystallite size was the minimum (27.72 nm) for the y = 0.08 (NCHF4) sample. • The sample has y = 0.08 (NCHF4) and contains maximum coercivity (1031.44 Oe). • The sample has y = 0.08 (NCHF4) and is best-suitable for high-frequency applications. [ABSTRACT FROM AUTHOR]

This study aims to investigate the microstructural, mechanical, and tribological characteristics of Al-nano TiC composites. The microwave-sintered nanocomposites were analyzed using optical and scanning electron microscopes, providing valuable insights into the spatial distribution and interaction of TiC within the matrix material. Microstructure characterization confirmed the uniform dispersion of nano TiC particles throughout the Al. Furthermore, the microwave-sintered nanocomposite samples displayed greater hardness than pure aluminum, indicating the strengthening impact of nano-TiC. Al-6 wt.% nanocomposites fabricated using microwave-sintered powder metallurgy showcased an impressive hardness rating of 51 VHN. The assessment of tribological properties revealed that a higher TiC concentration reduced wear rate, showcasing improved surface protection. However, it was observed that the friction coefficient rise with the addition of nano-TiC particles, implying changes in the bonding between the composite and the interacting surface. The thorough examination of worn surfaces yielded insights into the wear mechanisms present in the nanocomposite materials. Detailed examination of worn surfaces highlighted the formation of protective oxide layers, contributing to the improved wear resistance. This research contributes to our understanding of the complex interactions occurring during tribological processes by clarifying the morphological features of worn surfaces. [ABSTRACT FROM AUTHOR]

Enhancing chemical mechanical polishing (CMP) performance is the key to improving the surface quality and processing cost of silicon carbide (SiC). However, traditional SiO 2 abrasive fails to meet the material removal rate (MRR) requirement for SiC processing. In order to solve this problem, we use chemical deposition method to coat MnO 2 on the surface of SiO 2 to enhance CMP performance. A series of SiO 2 @MnO 2 composite abrasives (the coating mass fraction of MnO 2 on the surface of SiO 2 is 0, 0.03 wt%, 0.05 wt%, 0.07 wt%, 0.10 wt%, respectively) are synthesized and characterized. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and the size distribution analyses confirm that the composite abrasive possesses a core-shell structure, wherein the core is composed of SiO 2 while the shell consists of MnO 2. The results of CMP experiments demonstrate that the MRR of SiO 2 @MnO 2 (0.05 wt%) can reach 403 nm/h, which is 220% higher than that traditional SiO 2 abrasive, effectively resolving the limitation of MRR in previous literature. Additionally, the surface roughness (Sa) is reduced to 0.62 nm (measuring area: 500 μm × 500 μm). X-ray photoelectron spectroscopy analysis, contact angle test and dynamic friction test are used to further explore the removal mechanism of composite abrasives in SiC CMP. As a result, Mn–O–Si bond is formed by chemical interaction between the slurry including SiO 2 @MnO 2 composite abrasive and SiC substrate, which weakens Si–C bond of SiC surface. The dynamic friction coefficient of the composite abrasive on SiC substrate is enhanced, implying that the coating of MnO 2 also increases the contact sites and mechanical effect between the abrasive and SiC. Under the synergistic action of chemical and mechanical effects, the MRR of SiC is improved, and a better flatness is obtained. [ABSTRACT FROM AUTHOR]

In this present investigation, novel hybrid magnesium composites were synthesized by the inclusion of self-lubricating (BN/MoS 2) and ceramic (ZrO 2) particulates with the help of the powder metallurgy technique. ZE41 magnesium (Mg–4Zn-1RE-0.7Zr) was applied for a broad range of components, including the gearbox casing, the framework of the door, and transmission in aircraft like the Sikorsky UH-60 and the Boeing 727. Apart from its structural application, its usage was limited because of its deficient wear and mechanical properties. This research focuses on enhancing the potential applications of the ZE41 magnesium alloy by improving its mechanical and tribological characteristics. The design of the experiment scheme was applied to explore the effect of individual reinforcements and their synergistic effects on various properties of prepared composites. Microstructural inspection was employed to inspect the morphological characteristics of prepared specimens through scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD). By analysing SEM, EDS, and X-ray diffraction patterns, the microstructural evaluation reveals uniform phase dispersion and the existence of reinforcements with some minor defects. As a result of the inclusion of reinforcements in composites, the hardness of the reinforced specimen improved to 39.65%, while the wear rate of the reinforced specimen decreased to 40.90% compared with monolithic alloy. A multi-objective grey relational analysis (GRA) optimization method was used to perform a detailed tribological analysis on Specimen G (ZE41 mg + 3% ZrO 2 + 3% MoS 2). According to the results of GRA, the optimized rate of wear and frictional coefficient were achieved on sliding velocity (4 ms−1), sliding distance (2000 m), and load (10 N). The worn surface micrograph reveals that the reinforced composite underwent abrasion and delamination wear, while the unreinforced alloy experienced plastic deformation. [ABSTRACT FROM AUTHOR]

Silicon carbide fiber reinforced silicon carbide ceramic matrix composite (CMC SiC f /SiC) has the advantages of high temperature resistance, corrosion resistance, high strength, low density, and oxidation resistance. It is a high-performance advanced material in aerospace, energy and other fields. However, due to its high hardness, brittleness and anisotropy of fiber structure, the research on application-oriented high-quality processing technology has become a hot issue. In this paper, a new process of rotational thirteen-beam coupling nanosecond laser processing of CMC-SiC f /SiC was studied. The rotational thirteen-beam coupling ablation experiments were carried out on CMC-SiC f /SiC workpiece. A laser beam is divided into thirteen beams and rotated around the beam center by using a beam splitter element. The morphology, structure and composition of ablation holes at different speeds were observed and analyzed by laser confocal microscope, scanning electron microscope, and X-ray energy dispersive spectrometer. It is found that the characteristics of rotational beam coupling have a significant effect on the laser ablation morphologies. The results show that the ablation region of CMC-SiC f /SiC is elliptical due to the fast heat transfer of fibers. The energy density distribution of the waist section of the Gaussian like beam after beam coupling is similar to the "W" shape, and the central energy is lower than the surrounding energy, and the ablation holes also show a similar "W" shape. With the increase of rotational speed, the hole depth first decreased and then increased, the hole diameter and roundness first increased and then decreased, and the hole section was "W" shaped. The ablation area can be divided into five parts: the white granular SiO 2 solid coverage area, the recast layer, the lower recast layer, the molten layer, and the heat affected zone. The rotational characteristics will make the reaction intensity of the whole ablation area more uniform in the circumferential direction. The formation mechanism and element distribution of each part were explored. The research work in this paper will provide a new technical way for the high-performance application of CMC-SiC f /SiC. [ABSTRACT FROM AUTHOR]

The effectiveness of silicon carbide (SiC) planarization mostly relies on the chemical and mechanical effects during chemical mechanical polishing (CMP). Nevertheless, the alumina (Al 2 O 3) abrasive only provides a mechanical effect and is incapable of achieving a high-efficiency polishing of SiC. To address this issue, a series of novel Al 2 O 3 @MnO 2 composite abrasives were prepared by encapsulating varying amounts of manganese dioxide (MnO 2) on Al 2 O 3 abrasive, and the polishing performance on SiC wafers was evaluated. The X-ray diffraction (XRD) and scanning electron microscope (SEM) images, along with the size and zeta potential data, show that MnO 2 is successfully coated on the surface of Al 2 O 3 , and the dispersion of Al 2 O 3 @MnO 2 composite abrasive is significantly improved when compared with the pure Al 2 O 3. Furthermore, the CMP experiment and surface profile analysis demonstrate that the material removal rate (MRR) can reach a maximum value of 640.47 nm/h when using a 0.05 wt% MnO 2 -coated Al 2 O 3 composite abrasive, which is 76 % higher than that of traditional Al 2 O 3 abrasive. Furthermore, the average surface roughness (Sa, arithmetic mean height) of SiC is reduced to 0.73 nm. X-ray photoelectron spectroscopy results reveal that the surface of SiC is oxidized and forms a chemical bond known as Mn–O–Si after CMP. The results of the friction coefficient test and contact angle test indicate that slurries containing composite abrasive have exceptional wettability and a higher friction coefficient. Under the synergistic chemical and mechanical effects, SiC is oxidized to soft oxide and then removed circularly to reach excellent flatness. [ABSTRACT FROM AUTHOR]

A composite coating of Ni–W–Ti 2 AlC was fabricated through direct current electrodeposition. The characterization of the composite coatings included analysis using X-ray diffractometry, scanning electron microscope, energy spectrum analysis, Vickers microhardness testing, electrochemical testing, and tribological testing. The findings indicate that the inclusion of Ti 2 AlC alters both the grain size and microstructure of the coatings. The presence of Ti 2 AlC particles facilitates the nucleation process during Ni–W–Ti 2 AlC deposition. The Ti 2 AlC content influences the coating's performance in the bath. Specifically, the microhardness of the Ni–W-(5 g/L) Ti 2 AlC coating exhibits the highest value, experiencing a 41.89 % increase compared to that of the Ni–W coating. Ti 2 AlC contributes to the rectification of defects in the Ni–W–Ti 2 AlC coating. This composite coating exhibits the lowest corrosion current and superior corrosion resistance, particularly with a Ti 2 AlC concentration of 5 g/L. The wear mechanism of the coating encompasses abrasive wear, adhesive wear, and oxidation wear. Notably, the Ni–W–Ti 2 AlC composite coating demonstrates enhanced friction resistance compared to the Ni–W composite coating. Incorporating Ti 2 AlC introduces a novel approach and avenue for fabricating high-performance tungsten-based functional coatings. [ABSTRACT FROM AUTHOR]

The applications of Si 3 N 4 ceramics are hindered by their brittleness and susceptibility to fracture, despite their high strength and wear resistance. To address this challenge, layered ceramics were prepared using lamination and plasma sintering techniques, inspired by the structure of shell pearl layers. The bio-inspired layered ceramics were alternately arranged with Si 3 N 4 as the matrix layer (hard) and BN as the interfacial layer (soft). During the study, ceramic specimens with different microstructures were obtained by modulating the layer thickness ratio (ratio of Si 3 N 4 to BN) and sintering temperature. The microstructure of the specimens was characterized using SEM (Scanning Electron Microscope) and EDS (Energy Dispersive Spectrometer). The mechanical of various specimens were assessed by measuring the flexural strength and fracture toughness. The results of the investigation revealed that the mechanical characteristics of the samples reached their optimum state (with a toughness of 13.51 ± 1.56 MPa m1/2 and a strength of 429 ± 4.28 MPa) when the ratio of Si 3 N 4 to BN was 5:1, and the sintering temperature was maintained at 2000 °C. [ABSTRACT FROM AUTHOR]

A nanostructure of lithium-zinc copper ferrite (LiZnCu-Ferrite) prepared experimentally by the auto-combustion method depends on different parameters. The auto-combustion method operates at a temperature (160 °C) suitable for preparing the required nanostructure ferrite phase. The dependent composition was [Li 0.5-x Zn x Cu x Fe 2.5-x O 4 at (x = 0, 0.05, 0.15, 0.25, 0.35, and 0.45)]. A pre-firing at temperature (650 °C) was applied during the calcination process that was suitable to remove unwanted products. The sintering at temperature (800 °C) was suitable for a pelletized shape of ferrite samples. The X-ray diffraction (XRD) pattern showed a spinel structure of ferrite phase produced for all samples under study with the lattice constant in the range (8.345–8.368 Å) as a function of (x). The crystallite size was in the range (18.41–30.27 nm) calculated by the Scherrer method. The transmission electron microscope (TEM) showed a production of nanorods in the size range (10–45 nm) and nanoparticles in the size range (10–40 nm). There was a coincidence between the results of the XRD and TEM analyses. On the other hand, the scanning electron microscope (SEM) showed the surface morphology and the nature of grain size, which was a sign of the presence of nanostructure; it agreed with the XRD analysis. FTIR spectra showed evidence that the system Li0.5-xZnxCuxFe2.5-xO4 had spinal ferrite nanoparticles successfully prepared by sol-gel auto-combustion. A vibrating sample magnetometer (VSM) showed a change in magnetic parameters as compensation factor (x) increased for all composites of LiZnCu-ferrite such as saturation magnetization (Ms), initial magnetic permeability (μi), remanence (Mr), and coercive force (Hc) that measured from M − H loops. A saturation magnetization increased as a function of (x) and recorded a maximum value at (x = 0.15). While the coercivity, initial magnetic permeability (μi), and remanence magnetization enhanced as a function of (x) and recorded a maximum value at (x = 0.45). [ABSTRACT FROM AUTHOR]

The main objective of this study is to fabricate composite materials having excellent thermal, mechanical and electrical properties for thermal and electronic applications. In this work, strontium feldspar-containing composites (Sr-feldspar/cordierite and Sr-feldspar/Sr-osumilite) were prepared by solid-state sintering of SrO-containing cordierite (MgSrAl 4 Si 5 O 18)/borosilicate glass powder mixtures. The phase composition, physical properties and microstructure of sintered composites were investigated by X-ray diffraction technique, water displacement method and scanning electron microscope, respectively. Moreover, the thermal expansion coefficient, hardness, and electrical properties were also measured. The results of X-ray patterns revealed the crystallization of Sr-feldspar and cordierite in the composites that contain up to 20% borosilicate glass. On the other hand, the composites that include more than 20% glass, displayed the crystallization of Sr-feldspar and Sr-osumilite with little amount of cristobalite. The bulk density values of sintered composites were decreased from 2.41 to 1.84 g/cm3 with increasing the amount of added glass. The microhardness values were increased from 519 to 710 kg/mm2 with increasing the glass content. Low thermal expansion coefficient (2.65 × 10−6, 2.22 × 10−6, 3.45 × 10−6 and 4.26 × 10−6 K-1 for C0, CG91, CG73, CG55, respectively) and low dialectic constant (7–8.5) were obtained for the prepared composites. [ABSTRACT FROM AUTHOR]

This research delved into the structural, morphological, and magnetic characteristics of rare earth doped strontium ferrites (SrRE x Fe 12-x O 19 (x = 0.05–0.2, RE = La, Sm, Eu, Dy, Er, Lu)) synthesized via the sol-gel method. The dopant ion radius is correlated with the performance of the material to a certain extent. Barium and calcium doping and related iron deficiency state experiments were designed to substantiate the reciprocal dependence between ion radius and coercivity. X-ray diffraction results revealed that doping ions had the capacity to modify lattice dimensions. The lattice size does not exhibit a clear linear relationship with the radius of the doping ion, nor does it inherently correlate with the grain size. The scanning electron microscope demonstrated that ion doping had the capacity to influence the size of grains. A general consequence of rare earth doping is the reduction in the saturation magnetization of strontium ferrites. The lanthanide contraction effect significantly influences the changes in coercivity. It is noteworthy that the variations in lattice internal space induced by doping constitute a primary driving factor for the observed coercivity dependence on the radius of the doping ion. [ABSTRACT FROM AUTHOR]

Osteogenic differentiation and bone regeneration can be effectively aided by porous scaffolds with multiscale cellular structures, making it easier to repair defects in bone tissue. Due to the scarcity of pore-forming agents, it is extremely challenging to fabricate interconnected hierarchically porous zirconia at multi-scale. This work described a novel and straightforward method for directly imprinting a slurry containing two pore-forming agents (microspherical and filamentary) to produce strong and highly porous zirconia (ZrO 2) ceramics with four levels of porosity ranging from nanometers to millimeters. The concentration of hemp fibers significantly affected printability when the rheological behavior of a zirconia slurry was examined. Utilizing a scanning electron microscope (SEM) to monitor the development of powder interstices under various sintering techniques. The permeability performance was assessed when simulated plasma had fully filled the scaffolds. The structure had a high compressive strength of 24.18 MPa, a porosity of 80.9 %, an apparent porosity of 55.7 %, and took just 1.11 s to fill a scaffold that was 15 mm high. It is anticipated that the proposed route will be expanded to include various engineering materials for structural and practical applications. [ABSTRACT FROM AUTHOR]

Daqiuni clay is an aluminosilicate clay with unique properties that make it a promising ceramic precursor. Understanding its sintering behavior is crucial for quality control in manufacturing. This study aimed to investigate the phase evolution, densification process, and reaction kinetics during sintering of Daqiuni clay. A combination of X-ray diffraction (XRD), simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques were employed to comprehensively analyse the phase transformations. The densification behavior, apparent activation energies, and reaction mechanisms were elucidated through thermodilatometric analysis conducted at varying heating rates. Four stages were identified during sintering including dehydration, dehydroxylation, mullite formation, and partial melting. The maximum shrinkages at each stage were measured. Kissinger analysis yielded apparent activation energies of 122.90, 258.40, 361.98 and 348.69 kJ/mol for the dehydroxylation, mullite nucleation, mullite growth, and partial melting stages, respectively. The dehydroxylation and partial melting processes followed the mechanisms of 3rd order reaction and 3D diffusion. Mullite formation was a two-step nucleation and growth process following the JMA model. This study clarified the phase evolution of Daqiuni clay during sintering. [ABSTRACT FROM AUTHOR]

This study successfully synthesized novel phosphors Ca 2 GaTaO 6 : x Dy3+ (CGTO: x Dy3+) and Ca 2 GaTaO 6 :0.06Dy3+, y Sm3+ (CGTO:0.06Dy3+, y Sm3+) using the high temperature solid-phase reaction preparation. The microstructure, optical properties, and energy transfer mechanism of the phosphors were studied through X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) spectra and fluorescence lifetimes. XRD and corresponding refinement results indicate that Dy3+ and Sm3+ ions were effectively doped into the Ca 2 GaTaO 6 (CGTO) lattice. The SEM graphs show that the elements in CGTO:0.06Dy3+, 0.5Sm3+ phosphors are uniformly distributed. PL spectra analysis show the CGTO: x Dy3+ phosphors display two strong emission peaks located at 482 nm for blue emission and 575 nm for yellow emission when excited with 350 nm light. Under uniform conditions, when excited with 365 nm of light, the CGTO:0.06Dy3+, y Sm3+ phosphors emit light that can be tuned with adjustable color coordinates and correlated color temperature (CCT) by incorporating varying proportions of Sm3+ ions. This tunability is achieved through the effective energy migration from Dy3+ to Sm3+ ions within the phosphor material. Furthermore, the emission spectra and weaken lifetimes of the CGTO:0.06Dy3+, y Sm3+ confirm the energy transport between Dy3+ and Sm3+, and the energy transfer efficiency reached to 76 %. At 423 K, the luminescence intensity of CGTO:0.06Dy3+, 0.05Sm3+ phosphor retains 87 % of the intensity observed at 298 K, signifying its excellent thermal durability. Finally, the electroluminescent performance of the CGTO:0.06Dy3+ and CGTO:0.06Dy3+, 0.05Sm3+ phosphors packaged on 365 nm light-emitting diode (LED) chips respectively were studied to investigate the capability applications of the phosphors in white light-emitting diodes (WLEDs) field. The CCT of the packaged LEDs decline from 3396 to 2825 K, indicating CGTO:0.06Dy3+, 0.05Sm3+ phosphor shifts to warmer white light. At a voltage input of 3.4 V and a current of 600 mA, the thermal sensing shows that the WLEDs maintain aptitude for 90 min, showing that the packaged WLEDs can function consistently under elevated temperatures. These studies indicated the phosphors have potential applications in indoor lighting. [ABSTRACT FROM AUTHOR]

High-performance Sr 0.99 La 0.01 TiO 3 ceramics were synthesized using a conventional solid-phase method, and Sr 0.99 La 0.01 TiO 3 percolated (SLT10-P) samples with excellent resistivity were obtained by coating with an oxidant and heat treatment. In this work, simultaneous excellent dielectric properties (16667 of dielectric permittivity, 0.016 of loss tangent at 1 kHz) and high resistivity (1.44 × 1011 Ω·cm at DC100V) was achieved in SLT10-P ceramics at room temperature by modulating the duration of thermal treatment. X-ray Diffraction and scanning electron microscope analyses proved the diffusion of the oxidant in the grains and grain boundaries during the heat treatment. The increase in grain boundary resistance is mainly due to the fact that the insulating layer formed by the oxide ions entering the grain boundary hinders the long-range movement of electrons. In addition, the diffusion of oxygen from the air into the ceramic during the heat treatment process also contributes to the insulation of grain boundaries. [ABSTRACT FROM AUTHOR]

Nitrogen dioxide (NO 2) exposure can have several adverse health impacts on people, especially the respiratory system. Low selectivity, a lack of long-term stability, and structural and morphological optimization are some challenges associated with using ZnO for NO 2 gas sensing. Therefore, we intended copper (Cu) doping in ZnO to alter its shape and gas-sensing characteristics. This study explores the synthesis, properties, and gas-sensing capabilities of bitter gourd-shaped Cu-doped zinc oxide (ZnO) nanostructures for the detection of nitrogen dioxide (NO 2). A facile hydrothermal synthesis method was employed to synthesize bitter gourd-shaped Cu-doped ZnO nanostructures and comprehensively characterized by several techniques. Comprehensive characterizations of our produced Cu-doped ZnO nanomaterial demonstrated by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS), and different energy spectrum. The material was annealed at 400 °C in a controlled dry air environment to improve its suitability for gas sensor applications. A series of temperature-ranging experiments were conducted to get gas-sensing readings from 25 °C to 300 °C. The resulting sensor, founded upon the distinctive morphology of Cu-doped ZnO structures reminiscent of the intricate shape of bitter gourd, unveiled good selectivity with a pronounced affinity for detecting NO 2 gas. Notably, the zenith of its performance was attained at an operating temperature of 200 °C, where its selectivity and sensitivity were most pronounced. Even at a low concentration of 1 ppm, the sensors displayed a maximum response of 3.7, highlighting their high sensitivity. The sensors demonstrated excellent reproducibility, selectivity, and a low detection limit. These findings position bitter gourd-shaped Cu-doped ZnO nanostructures as promising candidates for NO 2 sensing applications across diverse environments. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of incorporating nanoparticles on the energy absorption properties of nanocomposites using low-velocity impact (LVI) testing and molecular modeling. Various types of thermoset polymer-based nanocomposites reinforced with carbon nanotubes (CNTs) and alumina were analyzed, and the effect of adding two types of nanofillers and microfiber as a filler material was investigated. The results show that the addition of nanoparticles significantly improved the elastic energy absorption properties of the nanocomposites at the atomic level. The LVI tests demonstrated that adding both types of nanoparticles, along with microfiber, significantly enhanced the energy absorption capacity of the four-phase composite under practical conditions. The scanning electron microscope (SEM) analyses revealed the morphology behavior of the nanoparticles. Incorporating both types of nanoparticles simultaneously with the polymer and fibers increased the elastic modulus by up to 163 %. These findings have significant implications for designing structures with energy-absorbing materials to reduce sports-related injuries. The use of nanocomposites with enhanced energy absorption properties can help to improve the performance of energy-absorbing structures and reduce the risk of sports-related injuries. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) multiferroic composites are more promising candidates for low-power consumption devices, next-generation spintronic devices, and multistate memory devices since they exhibit significantly higher Magnetoelectric interaction over single-phase multiferroics. In this regard magnetic behaviour, dielectric, and magnetoelectric characteristics of a novel Pb-free (1-x) Na 0.5 Bi 0.5 TiO 3 -(x) Ni 0.5 Co 0.5 Fe 2 O 4 , (x = 0, 0.2, 0.4, 0.6, 0.8 & 1) particulate composites were explored. Solid-state synthesis was adopted to prepare the single-phase Na 0.5 Bi 0.5 TiO 3 (NBT), Ni 0.5 Co 0.5 Fe 2 O 4 (NCFO), and their composites. The presence of rhombohedral NBT and cubic inverse spinel NCFO in the composites were confirmed with X-ray diffraction (XRD) patterns. Microstrain (ε) induced in the prepared samples was estimated by using the Williamson-Hall (W-H) method. The piezoelectric NBT phase shows the tensile strain and the ferromagnetic NCFO shows the comprehensive strain. Among all the composites 0.8NBT-0.2NCFO shows a higher strain value of 0.012%, and the decrement in the strain values was observed upon increases in ferrite concentration. Backscattered scanning electron microscope (BS-SEM) images revealed the existence of highly dense uniformly distributed elements and Energy dispersive spectroscopy (EDS) confirmed the existing elements in the composites. UV–vis absorbance spectra disclosed a rise in energy gap values from 1.14 eV to 3.0 eV with increasing NBT percentage. Variations of dielectric permittivity and dielectric loss with respect to AC frequency were studied at room temperature (RT), and the 0.2NBT-0.8NCFO sample shows a high dielectric permittivity of 8500 at ∼100Hz. M − H (Magnetization-Magnetic field) hysteresis loops demonstrate the pure ferrite phase has a coercive field (H c) = 578 Oe, remnant magnetization (M r) = 21.43 emu/g and saturation magnetization (M s) = 71.29 emu/g. The M s and M r values in the composites are enhanced with increasing ferrite percentage. Studies on ME behaviour of (1-x) NBT-(x) NCFO, (x = 0.2,0.4,0.6 & 0.8) show the coupling effect between both the phases at room temperature and the highest coupling coefficient value 3.16mV/Cm. Oe was observed for the 0.8NBT-0.2NCFO further the reasons and mechanisms are discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

SrFe 12 O 19 is widely used due to its low cost, stability and corrosion resistance. In this study, Sm-doped porous SrFe 12 O 19 powder with high coercivity was synthesized using KCl- assisted spray pyrolysis. The Sm doping, microstructure and magnetic properties were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results showed that when Sm-doping amount was 0.2, the ferrite powder prepared by KCl-assisted spray pyrolysis had high coercivity of 7.286 kOe and saturation magnetization of 56.422 emu/g. The coercivity of the Sm-doped samples increased by 39.23 % compared with that of the undoped samples. The significant increase in coercivity was associated with the improvement of super-exchange interaction between Fe3+ particles caused by Sm doping, and the size decrease of the hexagonal plate Sr-ferrite particle caused by KCl action. The influencing mechanism of coercivity was discussed in detail based on the analysis of crystal structure and microstructure observation. [ABSTRACT FROM AUTHOR]

With the increasing consumption of non-renewable energy sources such as fossil fuels, human beings are facing the crisis of energy shortage. Therefore, researchers in most regions and countries in the world are actively committed to designing and developing new dielectric energy storage components with high energy storage density and high energy storage efficiency. In this work, 2-dimensional flaky Na 0.5 Bi 0.5 TiO 3 (NBT) inorganic powders were prepared by the two-step molten salt method and compounded with polymer polyvinylidene fluoride (PVDF). NBT/PVDF monolayer and 'sandwich' structure composites were prepared by the tape casting method, and the flaky NBT powders were arranged in parallel in the PVDF matrix. The phase and microstructure of the prepared NBT powders were analyzed by X-ray diffractometer and scanning electron microscope. The dielectric, conductivity, ferroelectric, and energy storage properties of the prepared composites were tested. The results show that the critical breakdown field strength of the prepared single-layer NBT/PVDF and 'sandwich' structure composites with a volume fraction of 0.75 vol.% NBT inorganic powder is 380 kV/mm and 540 kV/mm, respectively. The energy storage density reaches 13.78 J/cm3 and 21.57 J/cm3, which is about 1.87 and 3.01 times the volume fraction of 0 vol.%. [ABSTRACT FROM AUTHOR]

La3+ substituted Mn 0.5 Co 0.5 Fe 2 O 4 ferrites were synthesized through sol-gel auto-combustion route. The impacts of varying doping concentrations (0.03, 0.06 and 0.09) were studied on synthesized samples' structural, optical, morphological, vibrational, and dielectric properties. The spinel cubic phase of synthesized samples was confirmed by X-ray diffraction (XRD) analysis; increased La3+ concentration has altered the structural parameters of prepared ferrites. Diffuse Reflectance Spectroscopy (DRS) shows a decrease in band gap with increasing concentration of La3+. Morphology has been reviewed by Field Effect Scanning Electron Microscope (FE-SEM), and elemental composition was confirmed by Energy Dispersive X-ray (EDAX) spectra. In addition, M − O stretching bonds were verified employing Fourier Transform Infrared (FTIR) spectroscopy. Raman Spectroscopy shows five modes, further confirming the spinel structure. The XPS spectra verified the +2 oxidation state of Manganese. Finally, the dielectric constant, tangent loss, and AC (Alternating Current) conductivity were analyzed with temperature at several frequencies. The experimental results have unveiled intriguing findings: the dielectric constant exhibited its maximum value at the lowest frequency within the investigated range, and it demonstrated an increasing trend with the rising temperature at a specific frequency. Notably, introducing La3+ through substitution has led to a noteworthy enhancement in the dielectric constant, underscoring the novel impact of this dopant on the material's electrical properties. A positive correlation existed between AC conductivity and temperature; as the temperature increases, so does the AC conductivity. Also, it was found to be maximum at maximum frequency value for all samples. Additionally, it can be deduced that raising the La3+ concentration in crystal improves the dielectric characteristics of Manganese Cobalt ferrites. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, a bright white oxide coating was successfully prepared on 6061 Al alloy by PEO process from an environmentally friendly and low-cost concentrated silicate electrolyte as an alternative for commonly used fluozirconate electrolyte. The characteristics of PEO processes and resulting coatings both in diluted and concentrated silicate electrolytes were investigated by using Optical Emission Spectrometer (OES), Scanning Electron Microscope (SEM), X-ray Energy Dispersive Spectrometer (EDS) and X-ray Diffraction Spectrometer (XRD). The thermal control properties of the coatings were evaluated by UV-VIS-NIR spectrophotometer and infrared emissivity spectrometer, respectively. The corrosion protection performances of the coatings were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. Results show that the discharges in diluted silicate electrolyte are more pronounced than those in concentrated silicate electrolyte. The more intensive discharges in diluted silicate electrolyte are related to plasma electrochemical reactions at the material surface or at the metal-oxide interface, facilitating to a relatively dense structure and complex oxides including α -Al 2 O 3 , γ -Al 2 O 3 and mullite. The weaker discharges in concentrated silicate are associated with the fast silicate anions deposition process, resulting in the formation of amorphous SiO 2 with a porous microstructure and high thickness. The coating prepared in concentrated silicate electrolyte is characterized by a bright white color in appearance and has much lower solar absorptance (α s) of 0.159 and higher emissivity (ε) of 0.90 than the coating prepared in diluted silicate electrolyte with α s of 0.429 and ε of 0.79. However, the coating prepared in concentrated silicate electrolyte has a little inferior corrosion protection performance compared with that prepared in diluted silicate electrolyte due to the more porous microstructure. [ABSTRACT FROM AUTHOR]

Photocatalyst technology is the most feasible method for the degradation of industrial pollutants as it requires lesser energy and is also highly efficient. In this study, we report for the first time the synthesis of strontium nitrate nanocubes (ST NCs) by two-step decoration strategy using silver nanoparticles (Ag NPs) and graphene oxide nanosheets (GO NSs) to form Ag/ST and Ag/ST/GO nanocomposites via facile ultrasonication route. The crystallinity, chemical composition, morphology, optical, photocatalytic and electrochemical measurements of the samples were characterized using x-ray diffractometer (XRD), x-ray photoelectron spectrometer (XPS), high-resolution scanning electron microscope (HRSEM), high-resolution transmission electron microscope (HRTEM), ultraviolet–visible (UV–Vis) spectrophotometer and electrochemical workstation. The synthesized 3%Ag/ST and 3%Ag/ST/3%GO nanocomposites demonstrated highest degradation efficiency for the degradation of methylene blue (MB) dye, resulting in 97 % and 99 % degradation in 60 min and 45 min. The samples demonstrated good stability and reproducibility throughout the degradation process. [Display omitted] [ABSTRACT FROM AUTHOR]

The present study presents an analysis of the structural, morphological and magnetic properties of multiferroic YbMnO 3 (YBO) due to Lu doping. YbMnO 3 (YBO) and Yb 0.85 Lu 0.15 MnO 3 (YBLu) were prepared using a conventional solid state reaction method. The investigation employed techniques such as X-ray diffraction (XRD), Field Effect Scanning Electron Microscope (FE-SEM), Raman spectroscopy and magnetic measurements. The X-ray diffraction (XRD) patterns of both samples confirmed the growth of these samples in a polycrystalline single hexagonal phase having space group P6 3 cm with no detectable impurities. The evaluation of crystalline parameters, such as lattice parameters, cell volume, specific bond lengths etc. has been carried out. The Lu-doped sample shows a minor reduction in cell parameters and cell volume which can be attributed to the smaller ionic radius of Lu3+. Lu doping in YBO results in slight shift in Raman Lines towards slightly frequencies which is the result of a small change in the average bond length. The effective magnetic moment of YBLu is found to decrease ∼6 % and the antiferromagnetic ordering temperature T N nearly remains the same because Lu3+ has zero magnetic moment. Both samples show ferri/ferromagnetic behaviour below 5 K due to the ordering of the Yb3+ lattice. [ABSTRACT FROM AUTHOR]

In order to solve the problem of high accumulation of silicon-manganese slag, this paper proposes a method to prepare foam ceramics with high porosity using silicon-manganese slag as raw material. Two types of silicon-manganese slag were obtained from different regions of Ningxia, China, and used to prepare foam ceramics. This was done with the help of one-step sintering method by adding SiC as a foaming agent and borax as a flux. The effects of chemical composition and crystal phase difference of silicomanganese slag on the physical properties, phase and micromorphology of foam ceramics were investigated. By adjusting the firing temperature and foaming agent content, the optimal process for the preparation of foam ceramics by two kinds of silicomanganese slag was determined. The phase and microstructure of the samples were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM), and physical analysis was carried out. The results show that when the sintering temperature of the Huiyi silica manganese slag (HYSM) sample is 1100 °C, the bulk density reaches the minimum value of 0.41 g/cm3, while the porosity and compressive strength are 86.26 % and 0.95 MPa, respectively. On the other hand, when the sintering temperature of the Tianyuan silica manganese slag (TYSM) sample is 1110 °C, the packing density reaches a value of at least 0.51 g/cm3, while the porosity and compressive strength are 80.07 % and 2.09 MPa, respectively. The XRD and SEM results show that the crystalline phase of the HYSM sample is mainly magnesium feldspar, while that of the TYSM sample is mainly diopside. In this study, two kinds of silicon manganese slag with different physical and chemical properties were used to prepare foam ceramics with high porosity, and a theoretical basis for the large-scale use of silicon manganese slag in foam ceramics was presented. [ABSTRACT FROM AUTHOR]

The phase composition, microstructure, and hydration process of C 3 A with different MgO content were compared to elucidate the mechanism of hydration resistance of CaO improved by MgO–C 3 A solid solution. The process of hydration heat release was detected by isothermal calorimetry and the hydration products were analyzed by X-ray diffraction and scanning electron microscope. The results showed that the addition of MgO resulted in lattice distortion of C 3 A. In the middle and late stages of the hydration process, Mg(OH) 2 and amorphous gel-like substances covered the surface of the unreacted C 3 A and reduced the hydration reaction rate. The addition of MgO effectively reduced the hydration activity of the MgO–C 3 A solid solution that indicated the addition of MgO can improve the hydration resistance of CaO materials. [ABSTRACT FROM AUTHOR]

In order to solve the problem of high accumulation of silicon-manganese slag, this paper proposes a method to prepare foam ceramics with high porosity using silicon-manganese slag as raw material. Two types of silicon-manganese slag were obtained from different regions of Ningxia, China, and used to prepare foam ceramics. This was done with the help of one-step sintering method by adding SiC as a foaming agent and borax as a flux. The effects of chemical composition and crystal phase difference of silicomanganese slag on the physical properties, phase and micromorphology of foam ceramics were investigated. By adjusting the firing temperature and foaming agent content, the optimal process for the preparation of foam ceramics by two kinds of silicomanganese slag was determined. The phase and microstructure of the samples were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM), and physical analysis was carried out. The results show that when the sintering temperature of the Huiyi silica manganese slag (HYSM) sample is 1100 °C, the bulk density reaches the minimum value of 0.41 g/cm3, while the porosity and compressive strength are 86.26 % and 0.95 MPa, respectively. On the other hand, when the sintering temperature of the Tianyuan silica manganese slag (TYSM) sample is 1110 °C, the packing density reaches a value of at least 0.51 g/cm3, while the porosity and compressive strength are 80.07 % and 2.09 MPa, respectively. The XRD and SEM results show that the crystalline phase of the HYSM sample is mainly magnesium feldspar, while that of the TYSM sample is mainly diopside. In this study, two kinds of silicon manganese slag with different physical and chemical properties were used to prepare foam ceramics with high porosity, and a theoretical basis for the large-scale use of silicon manganese slag in foam ceramics was presented. [ABSTRACT FROM AUTHOR]

The phase composition, microstructure, and hydration process of C 3 A with different MgO content were compared to elucidate the mechanism of hydration resistance of CaO improved by MgO–C 3 A solid solution. The process of hydration heat release was detected by isothermal calorimetry and the hydration products were analyzed by X-ray diffraction and scanning electron microscope. The results showed that the addition of MgO resulted in lattice distortion of C 3 A. In the middle and late stages of the hydration process, Mg(OH) 2 and amorphous gel-like substances covered the surface of the unreacted C 3 A and reduced the hydration reaction rate. The addition of MgO effectively reduced the hydration activity of the MgO–C 3 A solid solution that indicated the addition of MgO can improve the hydration resistance of CaO materials. [ABSTRACT FROM AUTHOR]

ZnO and CuO nanostructured oxide ceramics were synthesized on ZnO-seeded micro-glass substrates (denoted as ZOZO and ZOCO, respectively), and their surface and gas-sensing characteristics were explored. The thin film seed layers were deposited using dip-coating and both ZnO and CuO nanostructures were produced through hydrothermal reactions under similar circumstances. X-ray diffraction patterns showed high crystallinity and texturization of ZOZO (in ZnO hexagonal wurtzite system) compared to ZOCO (in CuO monoclinic system). X-ray photoelectron measurements demonstrated the proper oxidation of Zn into Zn2+ in ZOZO and Cu into Cu2+ in ZOCO. Scanning electron microscope images revealed one-dimensional bundled nanorod-like structures in ZOZO and two-dimensional nano-coffee bean-like structures in ZOCO. The different morphologies induced different wettability features as indicated by water contact angles where the hydrophilic surface nature of ZOZO was more advantageous for NH 3 detection compared to ZOCO. Gas sensing measurements in 100 ppm NH 3 medium showed initially better results by the ZOCO sensor at a low operating temperature (70 °C, S = 9%) compared to the ZOZO sensor which did not show any credible sensitivity below 90 °C. However, as temperature increased, the ZOZO sensor exhibited an ultra-sensitivity of S = 275% at an optimal operating temperature of 150 °C with a limit of detection of 7 ppb whereas the ZOCO sensor recorded a maximum sensitivity of S = 19% at an operating temperature of 170 °C with a limit of detection of 40 ppb. Both sensors showed good repeatability, long-term stability, and selectivity towards ammonia gas. The variation in the properties of the produced films was discussed based on a seed-mediated approach that is consequently suggested to control the growth and alignment of nanoscale structures and their efficiency in subsequent device applications. [ABSTRACT FROM AUTHOR]

In this work, textured ceramics were successfully obtained using press-compaction-assisted binder jetting for the first time. A mixture of alumina nanoplatelets and nanoparticles was used as the feedstock powder (the nanoplatelets served as templates for epitaxial grain growth during sintering while the nanoparticles were consumed by the grain growth). The nanoplatelet fraction in the mixture was varied from 0 wt% to 50 wt%. Green samples were prepared with a lab-designed press-compaction-assisted binder jetting machine. The green samples were then sintered in a furnace and their sintered densities were measured. A scanning electron microscope and X-ray diffractometer were used to investigate the degree of texture in the sintered samples. Finally, the biaxial flexural strength of the sintered samples was measured. As the nanoplatelet fraction increased, the sintered density decreased, but the degree of texture increased. Interestingly, the biaxial flexural strength of the sintered samples with 5 wt% or 10 wt% nanoplatelets was higher than those without nanoplatelets, suggesting the increased degree of texture has a stronger effect on the mechanical response than the reduced sintered density under these conditions. [ABSTRACT FROM AUTHOR]

High-entropy MAX phase (Ti 0.5 Nb 0.15 Zr 0.1 Mo 0.1 Ta 0.1 W 0.05) 2 AlC was synthesized via current-assisted sintering using Ti/Al/NbC/ZrC/MoC/TaC/WC as the raw material. The phase composition, microstructure, and elemental distribution are analyzed by X-ray diffraction, scanning electron microscope and transmission electron microscope with energy-dispersive spectrometer elemental analysis. The results obtained indicate that the as-synthesized bulk exhibits high purity with minimal elemental segregation at the grain boundary. The doped atoms caused numerous dislocations and severe lattice distortions in the crystal structure. By means of mechanical properties tests, the hardness, flexural strength, and fracture toughness of (Ti 0.5 Nb 0.15 Zr 0.1 Mo 0.1 Ta 0.1 W 0.05) 2 AlC are determined to be 9.3 ± 0.2 GPa, 433 ± 27 GPa, and 8.9 ± 0.3 MPa m1/2, respectively. These findings demonstrate notable enhancements in terms of hardening, strengthening, and toughening effects compared to the Ti 2 AlC phase. [ABSTRACT FROM AUTHOR]

Li 2 Ti 0.85 (A 1/3 Ta 2/3) 0.15 O 3 + x wt.% H 3 BO 3 (A = Zn, Mg; 1.0 ≤ x ≤ 5.0) (LTATB x) ceramics were fabricated by the traditional solid phase synthesis method. The LTATB x ceramics belong to monoclinic structure which was checked by the X-ray diffraction (XRD). The microstructure of Li 2 Ti 0.85 (A 1/3 Ta 2/3) 0.15 O 3 ceramics could be improved by the addition of H 3 BO 3 , which was directly observed by the scanning electron microscope (SEM). The optimum dielectric properties (107,490 GHz and 57,543 GHz) of Li 2 Ti 0.85 (A 1/3 Ta 2/3) 0.15 O 3 ceramics were obtained when the x values are equal to 1.0 and 3.0, respectively. Since the addition amount reached 5.0, the sintering temperature declined to 900 °C and 950 °C, respectively. The patch antennas prepared with LTZTB 1.0 and LTMTB 3.0 ceramics were simulated and measured. The results from measured indicated that the S11 parameters in LTZTB 1.0 and LTMTB 3.0 based patch antenna are less than −15.0 dB, and the VSWR is close to 1.0, which basically meets the application requirements of external antenna. [ABSTRACT FROM AUTHOR]