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The cubic phase of Magnesium oxide (MgO) nanoparticles is synthesized by the sol-gel method. The nanoparticles were subjected to annealing at 500∘C to enable stress and strain analysis. Characterization of the annealed nanoparticles was performed using powder X-ray diffraction (XRD). Through analysis of the XRD peak profile, key properties, such as crystallite size, lattice strain, deformation stress, and deformation energy density, were determined. These parameters were estimated using three models such as the Williamson–Hall-Isotropic Strain Model (W-H-ISM), the Williamson–Hall-Anisotropic Strain Model (W-H-ASM), and the Williamson–Hall-Energy Density Model (W-H-EDM). The estimations were based on the W-H plot derived from the powder XRD data. The findings of this study contribute to a better understanding of the structural and mechanical characteristics of annealed MgO nanoparticles, thus informing their potential applications. [ABSTRACT FROM AUTHOR]

AbstractX-ray diffraction is an important technique used to determine crystallite size in materials science. However, determining the crystallite size accurately from X-ray diffraction data can be challenging due to the peak broadening and shape complexities. In this study, a genetic algorithm (GA) is employed to optimize the determination of crystallite size using X-ray diffraction data. The GA is used to fit a combination of Gaussian, Lorentzian, and Voigt functions to the X-ray diffraction data and determine the optimal crystal size. The optimized crystallite size is found to be consistent with other characterization techniques, demonstrating the validity of the proposed GA approach. Overall, this study presents a novel approach for the determination of crystallite size from X-ray diffraction data using GA optimization, which can be widely used in the field of materials science for accurate and efficient characterization of crystalline materials. [ABSTRACT FROM AUTHOR]

In this work, Gadolinium (Gd3+) substituted Co–Cu–Cr (CCC) SFs with the chemical formula Co 0.5 Cu 0.5 Cr 0.5 Gd x Fe 1.5-x O 4 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) were synthesized via the self-combustion process. The single-phase matrix of the Gd3+ substituted CCC SFs was verified using X-ray diffraction (XRD). The crystallite size (D) of Gd3+ doped CCC SFs was reduced from 51.20 nm to 36.27 nm with increasing Gd3+ doping. The addition of Gd3+ in the CCC SFs lattice enhanced specific surface area (S) from 22.11 cm2/g to 28.57 cm2/g. The energy bandgap (E g) was increased from 4.83 eV to 5.40 eV and revealed an inverse relation with crystallite size. The tangent loss (tan δ), dielectric loss (ε ″), dielectric constant (ε ′), and ac conductivity (σ a c ) of Gd3+ doped CCC SFs exhibit frequency-dependent behaviour. The behaviour of these dielectric properties has been analyzed using both Koop's theory and the Maxwell-Wagner model. Moreover, it was found that the ε ′ was enhanced, while σ a c and tan δ w as reduced with the doping of Gd3+ in CCC SFs. The saturation magnetization and microwave operating frequency were increased with the doping of Gd3+ in CCC SFs. Because of their diverse dielectric and magnetic properties, the Gd3+ doped CCC SFs have considerable potential for different applications, including microwave absorption materials, switching high-frequency devices, and microwave frequency-operating devices. [ABSTRACT FROM AUTHOR]

Co-precipitation, a rapid and effective technique, was used to produce Ce- and W-doped NiO nanoparticles at pH values of 10 and 12. The FT-IR, UV-visible spectroscopy, and X-ray diffraction techniques were used to examine the structural and optical characteristics. The NiO nanoparticles' distinct XRD pattern revealed their monoclinic shape and crystalline origin. According to the Debye-Scherrer formula, the crystallite size of NiO nanoparticles decreased to 5.94 nm and 7.12 nm, respectively, when 5% Ce and 5% W were added, from 20.41 nm for undoped. Using UV-VIS absorption spectra, the optical band gap and the wavelength of maximum absorption were found. It was found that both of these parameters were influenced by the pH level and the concentration of Ce and W metal dopants. It can be concluded that doping has a higher impact on Cerium compared to Tungsten and at pH 10 compared to pH 12. This work presents a comprehensive investigation of the effects of pH and dopant concentration on the properties of Ce and W-doped NiO nanoparticles. [ABSTRACT FROM AUTHOR]

Cadmium Selenide CdSe thin films were deposited on (7.5x1.3x0.1 cm³) glass substrates and (1x1 cm²) p-type silicon substrates using pulsed laser deposition technique (Nd: YAG laser beam with 80 mJ energy, λ = 1064 nm). Then, they were annealed at 300 °C for 1 h to get diodes as visible light detectors. Some of these samples (diodes) were exposed to different intervals (5, 7, 9, 12) days of neutron radiation using (241Am-10Be) source with a flux of 3x105 n/cm².s and energy of 5.71 MeV. For comparison purposes, the other diodes were kept without any irradiation The morphological and electrical properties of these samples were studied by XRD, FE-SEM and I-V measurements. Results have shown all these thin films exhibit a hexagonal structure. However, there is a slight shift in the preferred orientation (100) for the irradiated films. Also, there was a new (102 - SiO2) peak that appeared in the irradiated thin film pattern. The crystallite size of pristine and (5, 7, 9, 12) days irradiated CdSe thin films were (26.9, 18.3, 24.9, 20.3 and 24.5) nm respectively, whereas, the mean particle size of the pristine film was 37 nm whereas for the irradiated films 53, 64, 73 and 92 nm. Results also show that the band gap of these samples increased from 2.17 eV for pristine thin films to 2.3, 2.48, 2.25, and 2.3 eV for the irradiated thin films. On the other hand, the results of I-V characteristics show the dark/light current. The current under illumination increases when exposed to small values of neutron radiation then it decreases with higher values of exposure. In contrast, the dark current decreases significantly with the irradiation. The effect of the irradiation was clear on the response/recovery period for all devices. Nevertheless, it was more profound in the response/recovery time of pristine devices. Also, the photo-responsivity of the pristine device was larger than the other devices and it was decreased with increasing absorbed doses. [ABSTRACT FROM AUTHOR]

As an electrochemical device that converts the chemical energy of fuel directly into electrical energy, the fuel cell is a new alternative technology that uses fuel from renewable sources and generates power for sustainable development and energy security. Among various types of fuel cells, the direct carbon fuel cell (DCFC) has higher efficiency because carbon fuel has higher energy density than liquid or gas fuel. However, the current development of DCFCs is still limited by the sluggish activity of the cathode reaction. In this study, a new composite cathode made of Gd0.2Ce0.8O1.9 (GDC) and SrFe1−xTixO3–δ (SFT) is developed for a Nicotiana tabacum-derived carbon fuel-based DCFC. The structural, optical, and electrochemical properties of the materials are systematically evaluated. X-ray diffraction analysis results show a cubic structure of GDC and cubic perovskite phase of SFT in the sample, with crystallite sizes of 37 and 15 nm, respectively. Ultraviolet–visible spectroscopy reveals an indirect band gap which exhibits a red shift. Fourier transform infrared spectroscopy confirms the presence of Ce–O, Sr–Ti–O, and Fe–O functional groups in all the samples. Scanning electron microscopy analysis shows the morphology and particle size of the materials. The sample Gd0.2Ce0.8O2-δ–SrFe0.96Ti0.04O1.9 exhibits the highest electrical conductivity of 4.96 S cm−1 in an oxygen atmosphere at 600 °C and a higher power density of 40 mW cm−2 at 600 °C compared to other samples using Nicotiana tabacum carbon fuel. These findings indicate that the developed composite cathode is an efficient cathode for low-temperature DCFCs. [ABSTRACT FROM AUTHOR]

For the first time, CuAlVMg high-temperature shape memory alloy (HTSMA) with unprecedented alloy composition and with extended solubility of vanadium element was fabricated as-cast ingot by arc melting method, then homogenization of the alloy in high β-phase temperature region and quenching in iced-brine water were performed, respectively. The characteristic forward martensite to austenite martensitic transformation (MT) temperatures were detected at around 390 °C, which put the novel alloy in the category of HTSMAs. The thermal response of the alloy at high-temperatures was observed by DTA test as coherent with usual Cu-based HTSMAs. The residual sub-eutectoid precipitations emerging at around 500 °C hindered the direct martensitic transformation. The martensite structure of the alloy was revealed by XRD, SEM and optical microscopy tests. [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]

Recent research in solid-state physics and materials engineering focuses on the development of new dielectric materials, with bismuth-based pyrochlores being already extensively applied in communications technology for their excellent dielectric properties and relatively low sintering temperatures. Herein, the structural, morphological, electrical, and magnetic properties of Bi1.34Fe0.66Nb1.34O6.35 ceramic, prepared by the sol–gel method and sintered at 500 °C, are investigated. The Rietveld refinement of the XRD pattern showed a cubic phase belonging to the space group Fd-3m and a crystallite size of 42 nm. Transmission electron microscopy further confirmed the crystallite size and the homogeneous distribution of Bi, Fe, Nb, and O elements, as evidenced by high-angle annular dark field imaging and STEM-EDX mapping. The morphology of the sample, assessed by scanning electron microscopy, is characterized by submicron-sized spherical particles. Dielectric spectroscopic studies revealed that the dielectric properties, strongly influenced by frequency and temperature, indicate the material's potential for energy storage due to lower dielectric loss compared to the dielectric constant. The observed relaxation phenomena, confirmed through variations in dielectric loss and loss tangent, highlight the influence of grain boundaries and temperature on electron hopping and charge carrier dynamics. Using SQUID magnetometry, we identified two distinct magnetic phases. The primary phase, corresponding to the Bi1.34Fe0.66Nb1.34O6.35 ceramic, exhibits an antiferromagnetic behavior below its Néel temperature at around 8.8 K. A secondary high-Curie temperature ferrimagnetic phase, likely vestigial maghemite and/or magnetite, was also detected, indicating an estimated fraction below 0.02 wt.%. [ABSTRACT FROM AUTHOR]

This work focuses on the detailed crystal structure and dielectric properties of LaCrO3 and Ni-doped LaCrO3 (LaCr 0. 9 Ni 0. 1 O 3) compounds. Both the samples were synthesized via the auto-combustion route. The orthorhombic crystal structure with Pbnm space group of both the synthesized samples was confirmed using X-ray diffraction measurements. The average crystallite size of LaCr 0. 9 Ni 0. 1 O3compound is 52.71 nm which was determined from the Debye Scherrer formula. In Ni-doped LaCrO3compound, the formation of Cr 4 + ions at the octahedral sites affects the dielectric properties. Enhancement in AC conductivity in LaCr 0. 9 Ni 0. 1 O3 compound is due to the hopping of charge carriers in the material. [ABSTRACT FROM AUTHOR]

The effect of 2MeV energy electrons with fluences from 0.5×1017 to 4.0×1017 electron/cm2 on the crystal structure, surface morphology, absorption spectrum, band gap, Raman spectrum and microhardness of ZnS crystal was investigated. The crystal structure of ZnS is face-centered cubic with space group F-43m. Upon irradiation with a fluence of 4×1017 electron/cm2, the unit cell parameter decreased by 0.0195Å, and the coordinates of the Zn+2 ions were changed. Irradiation with fluences ranging from 0.5×1017 to 4×1017 electron/cm2 increased crystallite size from 20nm to 28nm. The study of the surface morphology of the ZnS single-crystal revealed that irradiation caused a reduction in both the width (Ra) and height (Rz) of the surface roughness. The band gap of the ZnS single-crystal decreased from 3.521 to 3.506eV when irradiated with fluence electrons from 0.5×1017 to 2.5×1017electron/cm2. Raman spectrum observations showed an increase in the longitudinal optical (LO) mode peak (350cm−1) intensity following the irradiation of ZnS single-crystal with electrons. The microhardness of the ZnS single-crystal showed an exponential increase by 20% when irradiated with fluences from 0.5×1017 to 2.5×1017electron/cm2. [ABSTRACT FROM AUTHOR]

Pure CdS and Cu2+/Mn2+‐doped CdS nanoparticles were synthesized using a green capping method via mechanochemical techniques, with starch as the capping agent. Characterization using XRD revealed a cubic phase structure of CdS nanoparticles, evidenced by peaks at 2θ values of 26.30°, 43.80°, and 51.80° corresponding to the (111), (220), and (311) planes, respectively. SEM‐EDAX analysis confirmed the presence of Cd, Cu, Mn, and S elements in the samples. Diffuse reflectance analysis indicated an average crystallite size ranging from 111 nm to 139 nm, accompanied by a band gap energy ranging from 2.25 to 1.95 eV. Raman spectroscopy identified peaks at 366 cm−1, 482 cm−1, and 556 cm−1, attributed to the skeletal modes of the pyranose ring in starch, thus confirming its presence in the starch‐capped CdS nanoparticles. [ABSTRACT FROM AUTHOR]

Recently, there has been extensive research on the synthesis of luminescent particles, as these materials show great potential for various industrial uses. Multiple matrices have been formulated, with the SrAl2O4:Eu2+, Dy3+ matrix being the most extensively studied due to its superior optical and structural properties. In this work, the objective of synthesizing SrAl2O4:Eu2+, Dy3+ particles were achieved by using a combustion approach. By optimizing the synthesis process and studying the impact of Dy3+-concentrations on the structural and optical features, it has proven feasible to regulate the reaction and attain exceptional optical characteristics. The importance of this investigation is in assessing the practical feasibility of using such a material. This study examines a phosphor composed of strontium aluminate (SrAl2O4) that is activated using various amounts of Dy3+(ranging from 0.1 to 0.8 mol %). The study's findings of XRD showed that the SrAl2O4:Eu2+, Dy3+samples had a monoclinic phase of space group P21. Increase in the dopant concentration, the size of the crystallites in SrAl2O4:Eu2+, Dy3+ samples decreased, as determined by Scherer's formula and the Williamson-Hall plot. The bandgap energy of doped SrAl2O4:Eu2+, Dy3+ nanoparticles was estimated using a Tauc plot based on data collected from an ultraviolet visible spectrophotometer. The results showed that the bandgap energy decreased from 6.5 to 5.5 eV as the level Dy3+rose from 0.1 to 0.8 mol %. FT-IR spectroscopy revealed a prominent vibrational stretching at 570 cm-1, which is likely due to the Al-O bond, and another stretching at 1049 cm-1, related to the Sr-O bonds of SrAl2O4:Eu2+, Dy3+ NPs. [ABSTRACT FROM AUTHOR]

The fashion industry's reliance on dyes contributes significantly to environmental pollution, which disturbs the ecological balance. To address this issue, we used ZnO/Mg combined with activated carbon (AC) at various concentrations (0.1 g, 0.5 g, and 1 g), which were synthesized via sol–gel and mechanical alloying processes. The analysis of X-ray diffraction shows reduced crystallite size, with d-spacing change (→ d ← ) for ZnO/Mg/AC (0.5 g) and (← d → ) for ZnO/Mg/AC (1 g), respectively. The results of the IR spectrum indicated the main vibrations is MgO and Zn–O bonds at wave numbers 673 cm−1 and 467 cm−1. It was found that ZnO/Mg/AC (1 g) shows high degradation performance D % : 86.15% as a consequence of reduced crystallite size: 22.67 nm, decreased skin depth: 0.002 cm, widening of optical phonon vibration ( Δ (LO - TO) ): 252 cm−1 and increased E g : 4.6 eV as a function AC variation. Moreover, the finding of high photocatalytic performance ≥ 80% for 0.25 mL MB dissolved in 250 mL distilled water is obtained from all composites. Based on these results, ZnO/Mg/AC shows potential as a photocatalyst to solve the MB waste problem. [ABSTRACT FROM AUTHOR]

In the present work, Al-doped (0, 1, 2 and 3%) ZnO nanoparticles (NPs) are synthesised by green combustion method (GCM) using Terminalia Catappa seeds (TCS) extract as a novel fuel. For the synthesis Zinc nitrate and Aluminum nitrate are used as precursor and dopant respectively. The synthesised NPs are characterised by XRD, FTIR, UV-vi and impedance spectroscopy. The XRD analysis shows decrease in crystallite size varies between 40 to 26 nm as dopant increases. The FTIR spectrum reaffirms the formation of Zn-O bonding structure at 454.28 cm−1. UV-Vi spectroscopic studies show the optical band gap of 3.63, 3.53, 3.22 and 3.19 eV for Al doped (0, 1, 2 and 3%) ZnO NPs. Thermal analysis for the synthesised Al-doped (0, 1, 2 and 3%) ZnO nanoparticles are analysed using TGA/DTA studies. The Electrical characteristics are studied at various temperatures (50 to 350°C) by varying frequency (10 Hz to 8 MHz). In low frequency regions, dielectric constant and dielectric loss increases with rise in temperature. The constant AC conductivity is observed in lower frequencies and increases for higher frequencies for all doped ZnO NPs. ZnO NPs prepared with 2% of doping exhibit improved structural and electrical properties. Hence these ZnO NPs may be used as sensing material for vibration sensor. Highlights: This paper focus on green synthesis of undoped and Al-doped ZnO nanoparticles by combustion method. ZnO nanoparticles are synthesised using zinc nitrate precursor, Aluminium nitrate as dopant and Terminalia catappa seed extract as fuel. Effect of Al (0, 1,2 and 3%) doping on microstructural, optical, thermal and electrical properties of ZnO nanoparticles are investigated. The green synthesised doped and undoped ZnO nanoparticles exhibit hexagonal wruzite structure with high crystallinity. The FTIR spectrum reaffirms the formation of Zn-O bonding structure at 454.28 cm-1 The optical band gap is found to be 3.63, 3.53, 3.22 and 3.19 eV for 0, 1,2 and 3% of Al doped ZnO nanoparticles respectively. AC conductivity of ZnO nanoparticles is found to be increased with 2% of Al doped ZnO nanoparticles. Result shows an improved structural, optical and electrical performance for 2% Al doped ZnO nanoparticles and hence these nanoparticles are suitable material for sensors, organic light emitting diodes and liquid crystal displays. [ABSTRACT FROM AUTHOR]

The sol-gel self-combustion technique was applied to form Cd–Co-based La-doped (Cd 0.5 Co 0.5 La x Fe 2-x O 4) spinel ferrite nanoparticles. A series of six samples was synthesized by varying lanthanum content from x = 0.00 to 0.20. The structural characteristics of the prepared nanoparticles were carried out using X-ray diffraction (XRD) analysis. The (311) plane verified that the prepared nanomaterials are in the spinel phase in all observed XRD patterns. The crystallite size for each sample was determined using the Scherrer formula found in the 8.7–17.8 nm range, which is well correlated with the SSP model. The crystallite size decreased while the lattice constant increased from 8.38 to 8.45 Å with increasing La-content. The increasing trend in the bulk density and X-ray density has been analyzed with the effects of La3+ contents. In Fourier-transform infrared spectroscopy (FTIR), the high-frequency absorption band (υ 1) was found from 522.15 to 541.06 cm−1, whereas the low-frequency band (υ 2) varied from 419.80 to 414.31 cm−1. The surface morphology was carried out by scanning electron microscope (SEM), which positively correlated with XRD analysis. Impedance analyzer (IA) assisted in observing the variations in complex dielectric properties of the compound in the frequency range from 1 MHz to 3 GHz. The dielectric constant and impedance plots depicted that the nano ferrites have good dielectric properties in low-frequency regions due contribution of polarization. While conduction can be made possible in the high-frequency areas as observed through AC conductivity. The electric modulus revealed the relaxation phenomenon at high frequency due to the hopping of electrons at the octa and tetrahedral sites. The magnetic properties were investigated to study the impact of La3+ ion under the applied magnetic field from −15 to 15 kOe. The saturation magnetization, and magnetic remanence were found from 40.6 to 27.7 emu/g and 19.6 to 2.7 emu/g, respectively. The synthesized nanoparticles can be utilized for microwave applications and magnetic storage devices. [ABSTRACT FROM AUTHOR]

a -axis-oriented AlN(100) films are identified as promising candidates for surface acoustic wave devices owing to their high transversal-acoustic velocity. Achieving uniform films across a wafer scale is crucial for enhancing device performance and minimizing manufacturing costs. In this study, we employ radio-frequency magnetron sputtering to deposit AlN(100) films on 2-in Si(100) wafers. We further examine the influence of various process parameters on the nonuniformity of film thickness and structural properties, including crystallite size, microstrain, and dislocation density. The optimization of parameters leads to the selection of a gas flow ratio of N 2 :Ar = 4:7, a sputtering power of 160 W, and a substrate temperature of 350 °C. Under these optimized conditions, the AlN films not only demonstrate a preferred (100) orientation and remarkable crystallinity, as indicated by a full width at half maximum of the X-ray diffraction peak of just 0.03°, but also achieve an optimal film thickness nonuniformity of 1.66 %. Our results offer valuable insights for the wafer-scale fabrication of AlN(100) films, potentially enhancing industrial production yields and reducing costs. [ABSTRACT FROM AUTHOR]

Copper-promoted iron oxides are commonly utilized in high-temperature water-gas shift (WGS) reactions. Although the promotional effect of Cu has been previously documented, the nature of the active sites for Cu/Fe 3 O 4 remains debated and the role of the crystallite size of Fe 3 O 4 has not been tackled. In this study, a wide range of Cu/Fe 3 O 4 catalysts were designed by hosting Cu species onto Fe 3 O 4 of two contrasting crystallite sizes (approximately 10 and 160 nm) and by utilizing different preparation methods (ammonia evaporation and deposition-precipitation). The evaluation of their catalytic WGS performances revealed a remarkable and previously undocumented phenomenon: the addition of Cu resulted in universal activity enhancements only for small Fe 3 O 4 crystals, while the larger analogues displayed decreased activity. This peculiar phenomenon can be explained by the creation of Cu–Fe 3 O 4 interfaces present in the iron oxides of small crystallite sizes. Thorough characterizations, such as advanced electron microscopic, in situ powder X-ray diffractions, in situ diffuse reflectance infrared Fourier transform spectroscopy, and computational studies, suggest strong electronic interactions between the different metal species, facilitated reductions of the individual oxides, and more favorable CO activation at the interfacial sites, all accounting for the promoted activity. [Display omitted] • Influence of Fe 3 O 4 crystallite size in water-gas shift reaction was examined. • Performance of Cu/Fe 3 O 4 in water-gas shift reaction was studied. • The formation of Cu–Fe 3 O 4 interfaces existed on small Fe 3 O 4 crystals. • Promotional effect of Cu was only found on small Fe 3 O 4 crystals. [ABSTRACT FROM AUTHOR]

This study focused on developing microstructural, thermal, and radiation shielding changes in Al50Si25B25 powders using mechanical alloying techniques. Based on the x‐ray powder diffraction data, the crystallite size and microstrain of the 100‐hours milled powder were calculated as 0.25 nm and 50.33 %, respectively. The solubility of silicon in the α‐aluminium matrix increased with longer mechanical alloying duration. Transmission electron microscope analyses further showed that the alloy particulates had an average size of 3 μm and an average grain size of 0.226 nm. The radiation shielding properties of the Al50Si25B25 powders indicated that the Linear Attenuation Coefficient value increased from 0.0554±0.1689 cm−1 to 1.0632±0.2425 cm−1 with an increase in the thickness of the Al50Si25B25 alloy. This work successfully demonstrated the potential of mechanical alloying techniques to enhance the microstructural and thermal properties of Al50Si25B25 powders. It highlighted their effectiveness in providing radiation shielding capabilities when varying the thickness of the alloy. [ABSTRACT FROM AUTHOR]

It is important to utilize the raw colemanite (RC) mineral, which has abundant reserves in the world, and to reduce its particles to smaller sizes for nanotechnology. However, not only the particle size of the produced colemanite powder but also its other properties need to be elucidated. By using the Taguchi design, the RC mineral was ground in a high-energy ball mill. From signal-to-noise (S/N) ratio, the smallest average particle size was found to be 3.10 µm for the experiment E04/nano-sized amorphous colemanite (NAC) powder. The characteristics of as-received RC mineral and synthesized NAC material were investigated using laser particle size analyzer, optical microscopes, SEM–EDS, XRD, TEM, HRTEM, and TGA–DTA devices. It was found that the NAC powder was not homogeneous, a small peak within the 300–20 nm range appeared, and d90, d50, d10, and dmin values were, respectively, 14.6 µm, 3.08 µm, 232 nm, and 26 nm. In the XRD analysis, the pure colemanite, calcite, and silica minerals were determined. The crystal structure of the NAC powder almost turned amorphous, and the crystallite size of (031) peak was reduced to 7.3 nm. It was deduced that the average particle size was 8.29 nm (R2 = 0.86), and the d-spacing value was 0.307 nm. This significant finding was attributed to the mobility of balls and moreover it was interpreted with an equation. An unknown transition in TGA–DTA was referred to the calcite mineral. Finally, it is believed that the synthesized NAC material will be beneficial to engineering studies as a natural/mineral additive. [ABSTRACT FROM AUTHOR]

Nanocrystalline NiFe thin films of 11 μm thickness have been deposited on Cu wire using an electrochemical technique in galvanostatic mode with a sodium gluconate (SG) additive in the plating solution. The SG concentration is systematically varied from 0 g/L to 80 g/L, which results in a substantial enhancement in the soft magnetic characteristics and magnetoimpedance (MI) ratio of the plated wire across a broad frequency spectrum, specifically attributed to the optimal inclusion of SG at 55 g/L. The observed improvements in magnetic softness and MI ratio are linked to the reduction in crystalline size and surface roughness and modifications in the microstructure influenced by the SG additive in the electroplating bath. Furthermore, an equivalence between experimental impedance data and the theoretical framework based on the analytical model of circumferential permeability is outlined to extract the material parameters of the permalloy magnetic films. These extracted parameters play a pivotal role, enabling a comprehensive understanding of the variation in the MI ratio as well as circumferential permeability of the thin films as a function of the SG additive concentration in the plating bath. The intricate association observed between the MI ratio and circumferential permeability suggests that the amplification of the MI ratio resulting from the inclusion of SG is linked primarily to enhancements in circumferential permeability and the incorporation of magnetic softness. Thus, the present work offers both a theoretical and experimental framework for future research in advanced MI-based devices for magnetic sensing applications. [ABSTRACT FROM AUTHOR]

Graphene nanoplatelets (GNPs) and spinel ferrites (SFs) composites enhance their properties and enable multifunctional applications, ranging from electronics to environmental and biomedical fields. This study investigates the Ni 0.4 Cd 0.6 Fe 2 O 4 /x-GNPs (x = 0 %, 2.5 %, and 5 %) [ NCF/0%GNPs, NCF/2.5%GNPs, and NCF/5%GNPs ] composites prepared via sol-gel auto combustion (SGAC) synthesis and their enhanced magneto-dielectric characteristics. XRD analysis confirmed the formation of a single-phase spinel matrix of NCF/GNPs composites and observed that the crystallite size (D) was enhanced from 22.8 nm to 33.6 nm with the increasing concentration of GNPs. Moreover, the bandgap energy (E g) was reduced with the incorporation of GNPs in the NCF sample. The dielectric constant and tangent loss were enhanced with the addition of GNPs in the NCF spinel lattice. The saturation magnetization and microwave operating frequency were reduced from 97.42 emu/g to 55.13 emu/g and 21.49 GHz–11.97 GHz, respectively, while the coercivity was observed to increase from 92.66 Oe to 263 Oe with the incorporation of GNPs in the NCF lattice. The study highlights the potential of NCF/GNPs composites for applications in electronics, energy storage, sensors, and biomedical devices. [Display omitted] • Sol-gel auto-combustion synthesis of NCF/GNPs composites. • Single-phase spinel matrix NCF/GNPs composites were observed via XRD. • The bandgap energy was reduced with the incorporation of GNPs. • The magnetic and dielectric properties were enhanced with the addition of GNPs. • The potential of NCF/GNPs composites for applications in electronics, energy storage, sensors, and biomedical devices. [ABSTRACT FROM AUTHOR]

The Size-Strain Plot (SSP) method has been modified and optimized for improved X-ray diffraction (XRD) analysis, particularly focusing on its application in probing the structural properties of pure and Ca-doped zinc oxide nanoparticles (Zn1 − xCaxO, x = 0.0: ZnO, x = 0.01: ZCa1, x = 0.03: ZCa3, x = 0.05: ZCa5). Zn1 − xCaxO nanoparticles were synthesized by a gelatin-based sol-gel method. Through rigorous experimentation and analysis, the optimized SSP method demonstrates enhanced accuracy and reliability in determining crystallite size and lattice strain. The structural properties of Zn1 − xCaxO, including crystallite size distribution and lattice strain effects, are thoroughly investigated, shedding light on the underlying mechanisms influencing ZnO's structural behavior. This refined SSP method offers valuable insights into the nanostructural characteristics of Zn1 − xCaxO, contributing to advancements in material science and nanotechnology. Also, the optical properties of the prepared samples were investigated in the UV-vis range. The results showed that adding calcium to zinc oxide with the mentioned amounts does not cause significant changes in its structure and optical properties. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cell is promising conversion technology due to fuel flexibility, higher efficiency, and environment friendly compared to traditional technology. To enhance the efficiency of the device, selection of anode material is important because it affects the electrochemical performance and operating temperature of the cell. In this work, La 0.5 Sr 0.5 Al x Cr 1-x O 3-δ (x = 0, 0.1, 0.2, 0.3, 0.4) anode has been developed using sol-gel method. XRD analysis exhibited a two-phase structure of the prepared anode, one orthorhombic and second rhombohedral phase with crystalline size in the range 15–18 nm. The surface morphology of the prepared anode material shows nano-spheres, dumbbells, and platelets. The elemental analysis confirms the presence of Sr, Cr, La, Al, and O in the prepared material. The metal-oxide formation has been confirmed with Fourier Transform Infrared Spectroscopy. The absorption spectra revealed red shift in bandgap 3.65–2.85 eV by increasing the Al concentration. The maximum dc electrical conductivity of the composition anode La 0.5 Sr 0.5 Al 0.4 Cr 0.6 O 3-δ is found to be 8.01 Scm−1 at 600 °C. The achieved power density of the anode La 0.5 Sr 0.5 Al 0.4 Cr 0.6 O 3-δ is 69 mWcm−2 using hydrogen fuel at 600 °C. [ABSTRACT FROM AUTHOR]

Boehmite nanoparticles (BNPs) were synthesized using a simple hydrothermal approach to attain optimal crystallite size, utilizing a novel directing agent. The synthesis process employed solutions of aluminum nitrate and urea, with a particular focus on the use of an environmentally friendly surfactant/bio-directing agent, namely xanthan gum. The effect of four key parameters, including the molar concentration of xanthan gum, the ratio of urea to aluminum nitrate molar concentrations (U/N ratio), reaction time, and the molar concentration of calcium chloride, was investigated using Taguchi design. Characterization of the samples was carried out through XRD, FESEM, EDX, and BET analyses revealing the presence of the boehmite pattern in all samples. The minimum crystallite size was achieved under optimized conditions (xanthan gum molar concentration of 2 mM, U/N molar ratio of 4, the reaction time of 12 h, and CaCl2 molar concentration of 1 mM) measured 10.76 nm with a specific surface area of 63.779 m2/g.

This study focused on the synthesis of gypsum nanocrystals using conventional wet chemical precipitation method from marine mollusks like Babylonia Japonica, Olive Sayana, and Conasprella bermudensis. Different characterization techniques like Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDX) were used to confirm the formation of the nanocrystals. XRD data assessed various structural parameters, including the dimension of the unit cell, crystallinity index, specific surface area, lattice parameters, dislocation density, and macrostrain. The Rietveld refinement study did not reveal the formation of alternate phases, and the predicted lattice parameters, Full Width at Half Maximum (FWHM), and X-ray density contradicted the actual data. The synthesized gypsum displayed crystallite dimension within the acceptable range of

The goal of this research was to synthesize activated carbon (AC) from discarded batteries, and the crystallographic characterization of the final product (AC), intermediate product, and raw sources were explored. The formation of activated carbon was confirmed by utilizing an X-ray diffractometer (XRD) that revealed the structure of activated carbon was hexagonal. The crystallite size of activated carbon was computed by applying several model equations (Linear straight-line method of Scherrer's equation, Monshi-Scherrer method, Sahadat-Scherrer method, Size-Strain plot method, Halder-Wagner method, Williamson-Hall method), and the range of calculated crystallite size was 5–28 nm. The weight loss occurred in the two stages those was explored by a thermogravimetric analyzer (TGA). Fourier Transform Infrared Spectrophotometer (FTIR) confirmed that there was no significant change in the peak position between intermediate product and activated carbon except for the intensity and peak separation difference. Field Emission Electron Microscope (FE-SEM) revealed several types of shapes of the waste source, intermediate product, and main product (AC).

In the present investigation, several biogenic sources of calcium were used to produce HAp nanomaterials by the use of a typical wet chemical precipitation technique. To determine the development of HAp nanocrystals, a variety of characterization methods were used, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. The results of XRD were used to evaluate a wide range of factors related to structure, such as lattice parameters, degree of crystallinity, dislocation density, microstrain, crystallinity index, and preference growth. The crystallite size of the produced HAp crystals was calculated using the equations of different models. Each of the formed HAp exhibits crystal arrangements that are within the allowed range of 1–150 nm, which the aforementioned models were used to figure out from the XRD information. Furthermore, the EDX examination (Ca, P, and O percentages) and Rietveld refinement (about 95 % HAp) verified the makeup of the resultant HAp particles.

Lead Zirconium Titanate (PZT) is a potential piezoelectric material for sensor and transducer applications due to its outstanding piezoelectric coupling near the morphotropic phase boundary (MPB). This is because PZT can switch between tetragonal and rhombohedral phases. PZT is still considered to be one of the piezoelectric materials that has received the greatest amount of attention from researchers and is used the most frequently. Modification with Lithium will improve the piezoelectric properties. In this study, the structural properties and morphological studies of Lead zirconium titanate and Lead zirconium titanate with Lithium modification have been evaluated. Various Scherrer’s models and other models, such as the Williamson-Hall model and Size-strain plots model, were used to display the observed fluctuations in crystallite size. Morphological analysis was used to determine the particle size. Graphs showing the distribution of particle sizes were drawn.

This paper examines the effect of ageing temperatures (400, 500, & 600 °C) and times (30, 60, & 90 min) on Ni-rich NiTi samples produced via the Laser Powder Bed Fusion (L-PBF) technique. Variations in the process parameters of the L-PBF which were examined included laser power at 150W and 180W, and the scanning strategy at 500 mm/s and 1000 mm/s. Ageing heat treatment enabled setting the functional properties of phase change temperatures, stress-strain response, and phase change enthalpies. Samples aged at 400 °C were found to have much higher austenitic finish temperature (40–60 °C) whereas those aged at 600 °C had near-zero or sub-zero Af temperatures. This was due to the lower nickel concentration resulting from the higher heat treatment temperature. Samples heat-treated at 500 °C exhibited Af temperature which was near to the room temperature and showed co-existence of both austenitic and martensitic phases. It was also found that the crystallite size increased from 6 to 22 nm for an ageing temperature of 400 °C, to between 38 and 48 nm for an ageing temperature of 600 °C. The highest microhardness value of 380HV was recorded from the lower heat treatment temperature and the lowest microhardness of 270HV was recorded for samples heat-treated at 600 °C. This decrease in the microhardness values is attributed to the increased crystallite size of the aged samples at higher temperatures. This work identifies for the first time the novel ability to control NiTi phase change temperature and mechanical properties using ageing heat treatments which is critical for the materials application for personalised stents. Higher heat treatment temperatures were found to lead to larger crystallite sizes.

This study highlights the photocatalytic activity of β-Bi2O3, particularly its role in degrading pharmaceutical pollutants harmful to the environment. Several approaches were implemented to characterize the β-Bi2O3 catalyst involving an X-ray diffractometer (XRD), Fourier Transform Infrared (FTIR) Spectrophotometer, Thermogravimetric analyzer (TGA), and Field Emission Scanning Electron Microscopy (FESEM). The computed crystallite size range from the XRD data was 10–66 nm; it was obtained by utilizing several models along with the Scherrer equations. The absorption bands were obtained through an FTIR Spectrophotometer, which also assured the formation of a Bi–O–Bi bond. The TGA analyzer revealed two-stage weight reductions (1.76 % and 7 %) up to 800 °C. After conducting FESEM analysis, it was found that the particles of β-Bi2O3 were in nanosheet shape with sharp edges. The photocatalytic efficacy was scrutinized by examining the interaction between the catalyst and the antibiotic (ciprofloxacin) depending on several parameters, in which the maximum degradation percentage was 91 % in the case of 0.05 g catalyst at 180 min under a halogen lamp. The photodegradation kinetics was observed utilizing the Langmuir-Hinshelwood model equation to compute the photocatalytic reaction rate. So, this research confirmed that β-Bi2O3 is an effective catalyst for treating antibiotic solution (ciprofloxacin) because leftover antibiotics are an alarming issue for the natural world.

High-temperature transport properties of the PrBaFe2O6−δ ceramics, prepared by different routes, were studied in the light of their potential use in energy conversion technologies. The PrBaFe2O6−δ oxides fabricated at 1000 °C and at 1350 °C are referred to as LTS and HTS, respectively, as synthesized at relatively low and high temperatures. The LTS oxide was shown to have a better oxygen exchange ability than HTS, starting oxygen release at a temperature ~ 200 °C lower when heating and adopting more oxygen when cooling. Dense ceramics were fabricated from the LTS oxide by a method, preserving the enhanced oxygen exchange ability. The electrical conductivity of the ceramics was measured by a four-probe DC technique as a function of oxygen partial pressure at 750–950 °C. The measurement results were analyzed using the data on charge carrier concentration revealed from the previously obtained data on oxygen content versus oxygen partial pressure. The mobility characteristics of n- and p-type carriers in PrBaFe2O6−δ were found to be practically unaffected by synthesis temperature. The average electron mobility was calculated to be ~ 0.007 cm2V−1s−1 at the migration energy of 0.5 eV, whereas the mobility and the migration energy of holes were ~ 0.08 cm2V−1s−1 and ~ 0.2 eV, respectively. Unlike electron carriers, the mobility of oxygen ions in PrBaFe2O6−δ was found to be affected by synthesis temperature. The average values of oxygen mobility and migration energy were determined to be ~ 1.1·10−5 cm2V−1s−1 and ~ 0.7 eV for the LTS oxide, whereas ~ 0.7·10−5 cm2V−1s−1 and ~ 0.8 eV for the HTS oxide. The oxygen ion conductivity of PrBaFe2O6−δ was found to reach 0.2 S·cm−1 at 900 °C, which is a characteristic of a high oxygen transport rate. [ABSTRACT FROM AUTHOR]

The development of the clothing industry contributes to the advancement of contemporary lifestyles, albeit with possible adverse implications for waste management. Photocatalysis process is a promising solution to degrade pollutants like methylene blue from textile waste. Iron sand/carbon (2.5 g:2.5 g) composites have been investigated and fabricated as catalysts using simple mechanical alloying for 30 min at 10 Hz as a green technique. By utilizing XRD, FTIR, UV–Vis, and SEM, the structural, optical, dielectric properties and surface states were investigated. IS/C/NaCl exhibits the highest performance with a degradation performance is achieved to 94.6%. The high longitudinal optical phonon vibration position, low penetration depth, and smaller crystallite size have a strong correlation to improve the degradation performance. The large surface area provided by the presence of carbon has an important effect on surface interactions to tune photocatalytic activity. It found that 0.25 g composite had a mass that was qualified to be applied to 100 mL dye solution for (15%, 30%, and 60%) MB concentrations. As additionally, the finding of high photocatalytic performance > 90% exhibited from all composites, indicating that the magnetite covered by carbon cloud is expected to be potential and promising catalyst for MB. [ABSTRACT FROM AUTHOR]

The structure, phase composition, hardness, and tribological properties of composite gas-thermal 50% Cu–50% (Al–Si) coatings under various friction conditions were studied. It has been shown that during the process of high-speed metallization, active interaction of molten aluminum and copper particles occurs, leading to the formation of solid solutions and intermetallic compounds in sprayed coatings. In particular, in 50% Cu–50% (Al–Si) coatings, in addition to the matrix phases of Cu and Al, intermetallic compounds Cu9Al4, CuAl2, and Cu3Al are recorded. The hardness and microhardness of the composite are 180 HV 1 and 180–190 HV 0.025, respectively. It has been established that a composite coating of 50% Cu–50% (Al–Si) has higher wear resistance under various friction conditions than the widely used coating of CuSn11P-C antifriction bronze, obtained by centrifugal induction surfacing. In particular, in the environment of I-20A lubricant, the wear resistance of the composite coating exceeds the wear resistance of bronze by ≈1.2 times, in the environment of Litol-24 plastic lubricant, by ≈1.4 times, and with dry friction up to ≈2.8 times. It has been shown that during boundary friction, dislocations accumulate in aluminum particles of the composite, while in copper particles at elevated test pressures, a predominant formation of a subgrain structure occurs. Based on the studies conducted, it was concluded that the increased wear resistance of the composite is due to the presence of solid intermetallic compounds in it, solid solution strengthening, the presence of silicon in aluminum interlayers, as well as dislocation strengthening of aluminum interlayers and the formation of a subgrain structure in copper interlayers. [ABSTRACT FROM AUTHOR]

High-temperature transport properties of the PrBaFe2O6−δ ceramics, prepared by different routes, were studied in the light of their potential use in energy conversion technologies. The PrBaFe2O6−δ oxides fabricated at 1000 °C and at 1350 °C are referred to as LTS and HTS, respectively, as synthesized at relatively low and high temperatures. The LTS oxide was shown to have a better oxygen exchange ability than HTS, starting oxygen release at a temperature ~ 200 °C lower when heating and adopting more oxygen when cooling. Dense ceramics were fabricated from the LTS oxide by a method, preserving the enhanced oxygen exchange ability. The electrical conductivity of the ceramics was measured by a four-probe DC technique as a function of oxygen partial pressure at 750–950 °C. The measurement results were analyzed using the data on charge carrier concentration revealed from the previously obtained data on oxygen content versus oxygen partial pressure. The mobility characteristics of n- and p-type carriers in PrBaFe2O6−δ were found to be practically unaffected by synthesis temperature. The average electron mobility was calculated to be ~ 0.007 cm2V−1s−1 at the migration energy of 0.5 eV, whereas the mobility and the migration energy of holes were ~ 0.08 cm2V−1s−1 and ~ 0.2 eV, respectively. Unlike electron carriers, the mobility of oxygen ions in PrBaFe2O6−δ was found to be affected by synthesis temperature. The average values of oxygen mobility and migration energy were determined to be ~ 1.1·10−5 cm2V−1s−1 and ~ 0.7 eV for the LTS oxide, whereas ~ 0.7·10−5 cm2V−1s−1 and ~ 0.8 eV for the HTS oxide. The oxygen ion conductivity of PrBaFe2O6−δ was found to reach 0.2 S·cm−1 at 900 °C, which is a characteristic of a high oxygen transport rate. [ABSTRACT FROM AUTHOR]

The detailed estimation of XRD microstructural elements such as Scherrer (Sch.) size of crystallite, Williamson-Hall (WH) size of crystallite and microscopic strain was highlighted via a novel modelling approach which relies on the broadening parameters named as the experimental broadening, crystallite size broadening and strain broadening. This approach was applied on the strain aged 6063 Al-alloys which are considered one of the backbones in the applications related to energy industries and manufacturers like vehicles and planes due to their light densities, availabilities and facile in fabrication. Three divergent aged specimens deformed at different percentages 0%, 5% and 30% respectively. The XRD results through modelling approach was comparable to the Rietveld MAUD (RM) refinement approach, which was served as a comparing and confirming tool. The estimated microstructural factors as a variation of the ageing time by the broadening analysis using the novel method were in a good agreement with Rietveld analysis using MAUD software program. The behaviour of both size of crystallite and micro strain exhibits two opposite pathways via the ageing time variation including small noises until to reach 400 hours at which the mean values of both of them nearly being constant for all distorted and non-distorted specimens. [ABSTRACT FROM AUTHOR]

The supercritical hydrothermal synthesis of nanomaterials has gained significant attention due to its straightforward operation and the excellent performance of the resulting products. In this study, the supercritical hydrothermal method was used with Zn(CH3COO)2·2H2O as the precursor and deionized water and ethanol as the solvent. Nano-ZnO was synthesized under different reaction temperatures (300~500 °C), reaction times (5~15 min), reaction pressures (22~30 MPa), precursor concentrations (0.1~0.5 mol/L), and ratios of precursor to organic solvent (C2H5OH) (2:1~1:4). The effects of synthesis conditions on the morphology and size of ZnO were studied. It was found that properly increasing hydrothermal temperature and pressure and extending the hydrothermal time are conducive to the more regular morphology and smaller size of ZnO particles, which is mainly achieved through the change of reaction conditions affecting the hydrothermal reaction rate. Moreover, the addition of ethanol makes the morphology of nano-zno more regular and significantly inhibits the agglomeration phenomenon. In addition to the change in physical properties of the solvent, this may also be related to the chemical bond established between ethanol and ZnO. The results show that the optimum synthesis conditions of ZnO are 450 °C, 26 MPa, 0.3 mol/L, 10 min, and the molar ratio of precursor to ethanol is 1:3. [ABSTRACT FROM AUTHOR]

Aluminum metal matrix composites find applications in several industries, such as aerospace, military, cars, sports equipment, and electronics. The primary objective of this experimental study is to obtain insights into the microstructural properties of an Al-Zn alloy that has been strengthened with copper. This investigation involved the preparation of an alloy including aluminum and zinc, which was afterward reinforced with varying quantities (0%, 0.4%, 1.2%, and 2%) of copper. In addition to conducting XRD tests to investigate the crystallite structure, particle size, and microscopic strain of the samples using the Scherrer and Williamson-Hall models, structural examinations were carried out using the EDS test to ascertain the elemental composition proportions. It was observed that the alloy (A-Zn-0.4%Cu) has smaller particle sizes than the other alloys under consideration. [ABSTRACT FROM AUTHOR]

The layered double hydroxides (LDHs) of transition metals are of great interest as building blocks for the creation of composite photocatalytic materials for hydrogen production, environmental remediation and other applications. However, the synthesis of most LDHs is reported only by the conventional coprecipitation method, which makes it difficult to control the catalyst's crystallinity. In the present study, ZnCr- and NiCr-LDHs have been successfully prepared using a facile hydrothermal approach. Varying the hydrothermal synthesis conditions allowed us to obtain target products with a controllable crystallite size in the range of 2–26 nm and a specific surface area of 45–83 m2∙g−1. The LDHs synthesized were investigated as photocatalysts of hydrogen generation from aqueous methanol. It was revealed that the photocatalytic activity of ZnCr-LDH samples grows monotonically with the increase in their average crystallite size, while that of NiCr-LDH ones reaches a maximum with intermediate-sized crystallites and then decreases due to the specific surface area reduction. The concentration dependence of the hydrogen evolution activity is generally consistent with the standard Langmuir–Hinshelwood model for heterogeneous catalysis. At a methanol content of 50 mol. %, the rate of hydrogen generation over ZnCr- and NiCr-LDHs reaches 88 and 41 μmol∙h−1∙g−1, respectively. The hydrothermally synthesized LDHs with enhanced crystallinity may be of interest for further fabrication of their nanosheets being promising components of new composite photocatalysts. [ABSTRACT FROM AUTHOR]

The study examines how SMAT influences the microstructure, dislocation density, and residual stress of AA7075-T6 alloy. SMAT involves the repeated impact of shots on a material surface within a vibration chamber, inducing severe plastic deformation and grain refinement. The study explores the interplay between vibration-induced shot effects and their impact on surface properties, emphasizing the importance of optimizing process parameters for improved material performance. Experimental analyses, including surface and subsurface microstructure examinations, X-ray diffraction (XRD) characterization, and residual stress evaluations, are conducted to elucidate the underlying mechanisms of SMAT. Results indicate that SMAT leads to significant plastic deformation, grain size reduction, increased dislocation density, and microstrain. The treatment produces a nanocrystallite layer, enhancing material properties. Residual stress measurements reveal a surface stress of −245 MPa, increasing to −360 MPa at 50 µm depth. The proposed multiple impact model accurately predicts deformation behavior, highlighting the deep pit regions formed during SMAT. This comprehensive investigation provides insights into the dynamic nature of SMAT and its potential for enhancing material properties. By integrating experimental findings with numerical modeling approaches, the study advances our understanding of SMAT-induced plastic deformation mechanisms and residual stress profiles. [ABSTRACT FROM AUTHOR]

Quantifying the active surface area of Mars‐van‐Krevelen catalysts is paramount for the elucidation of structure‐property relationships and the knowledge‐based catalyst development. Different cerium oxides were prepared via precipitation‐based techniques. By altering conditions during precipitation, materials with a wide span of material properties were prepared. The influence of temperature during ammonia‐based precipitation was investigated. When using Ce(IV) precursors an increase in precipitation temperature decreases the crystallite size while increasing specific surface area, attributed to an increase in nucleation rate. Sintering stability is also increased for materials precipitated at higher temperature. Measuring the total oxygen storage capacity (TOSC) values of the prepared materials showed that the TOSC is not strictly a function of BET surface area. Our results suggest that crystallites with a domain size under a certain threshold are not reduced via oxygen release but rather hydroxyl formation. A method was proposed with which the redox active surface area for polycrystalline ceria can be estimated on basis of the domain size obtained from Rietveld refinement. These findings were corroborated by CO oxidation light‐off experiments in which the light‐off temperature was found to correlate with the surface that can release oxygen reversibly, the Mars‐van‐Krevelen active surface area, rather than BET surface area. [ABSTRACT FROM AUTHOR]

In this article a complete procedure to investigate thin semiconductor plates (epitaxial layers), including high-resolution X-ray diffraction measurements, mathematical modelling of both crystalline structure and crystalline microstructure and computations to approximate solving inverse problems, is proposed and described in detail. The method is successfully applied to estimate crystalline homogeneity of a square indium-arsenide plate epitaxially-grown on gallium-arsenide substrate. To this end, the specimen is tested in nine areas around points forming a square grid. It is demonstrated that whole specimen may be regarded as a single large crystalline grain consisting of crystallites separated by small-angle boundaries. The crystallites occur as rode-like cuboids elongated in the direction perpendicular to the plate surface, with different areas of the sample and with base sizes not much differing. The mean-absolute second-order strain is very small and almost constant in the whole sample. The first-order strain also appears and, effectively, the structure of the crystalline layer is tetragonal with unit-cell parameters being smaller parallelly and larger perpendicularly to the layer surface and varying slightly in the layer. The results are presented in tables and figures and commented. [ABSTRACT FROM AUTHOR]

La1-xGdxFeO3 (x = 0 to 0.25) nanoparticles are prepared by microwave combustion process (MCP) with L-alanine as a fuel. The synthesized samples were characterized by XRD, TEM, SAED, XPS, FE-SEM, EDX, FTIR, DRS-UV and VSM analysis. XRD and FT-IR confirmed that lanthanum ferrite has an orthorhombic structure with an average crystallite size ranging from 57.8 to 37.9 nm. The energy gap values were estimated using UV–vis spectra and it is in the range between 2.17 and 2.43 eV. The elements Gd, La, Fe and O are present in EDX and XPS analysis. FE-SEM images reveal aggregated spherical morphology. VSM analysis shows strong ferro magnetic behavior of La1-xGdxFeO3 nanoparticles. The Ms and Mr values are in the range between 5.63 to 6.54 and 0.76 to 1.71 emu/g for La1-xGdxFeO3 respectively. The experimental results of this work hold promise for further advancements and novel uses in various fields of technology and industry, include solid oxide fuel cells, oxygen separation membranes, gas sensors, catalysis, magnetic devices, electrochemical devices, and potential use in environmental and thermoelectric applications. [ABSTRACT FROM AUTHOR]