Crystallite Size Research Articles

Continuous-Flow Synthesis of Zn1-xMnxS Nanoparticles at Ambient Conditions.

With its large direct band gap and good chemical stability, ZnS is suitable for many applications, including light-emitting diodes, panel displays, and photodetection. Here, nanoparticles of ZnS are synthesized phase pure under ambient conditions by precipitation in a simple and scalable continuous-flow reactor. Furthermore, different degrees of Zn substitution with Mn have been investigated, Zn1-xMnxS, with x = 0.05, 0.19, and 0.25 according to X-ray fluorescence measurements. The products are analyzed with multitemperature synchrotron powder X-ray diffraction (PXRD) and X-ray total scattering. The analysis reveals phase-pure synthesis products with the sphalerite structure and crystallite sizes in the range of 3.8-4.7 nm in agreement with scanning transmission electron microscopy. Only Zn0.75Mn0.25S shows traces of Mn3O4, indicating that x = 0.25 is above the substitution limit as the impurity appears. Substitution of Zn with Mn in the nanoparticles is confirmed by energy-dispersive X-ray spectroscopy, as well as an observed decrease in the band gap, decrease in the sphalerite-to-wurtzite phase transition temperature, and increase in the unit cell dimensions with increasing Mn content. Based on the modeling of the PXRD Rietveld refined atomic displacement parameters, the Debye temperature for ZnS and Zn0.95Mn0.05S is determined to be 322 ± 13 and 394 ± 22 K, respectively.

A novel nanoparticles spilled-over In2O3 microcubes-enabled sustainable chemiresistor for environmental carbon dioxide monitoring

Achieving sustainable future energy goals includes enhancing renewable energy production, optimizing daily energy consumption using feedback loops and minimizing/monitoring contributions to atmospheric carbon dioxide (CO2). Developing economic next-generation CO2 sensors enables local monitoring of industrial CO2 emissions, aiding energy management and climate monitoring. This study elucidates the efficacy of CO2 chemiresistor based on indium oxide (In2O3) micro cubes with spilled-over nanoparticles. The investigation primarily focuses on fabricating and optimising In2O3-based CO2 chemiresistors utilizing a hydrothermal technique, creating porous micro cubes essential for enhanced CO2 monitoring. As revealed by various characterization techniques, the minimum crystallite size was found to be 24.92 nm with optimum porosity and a high surface-to-volume ratio comprising spilled-over nanoparticle morphology. The fabricated chemiresistor demonstrated excellent CO2 sensing efficacy with a maximum response of around 4.1% at room temperature with selectivity, repeatability, and reversible sensing behavior. The sensing mechanism has been revealed, which is supported by theoretical density functional theory evaluations. Notably, the sensing results reveal the capability of In2O3-based sensors to detect CO2 at low concentrations as low as ⩽10 ppm, which enables the chemiresistor for practical implementation in diverse sectors to achieve sustainability.

Bioinspired copper oxide nanocomposites: harnessing plant extracts for enhanced photocatalytic performance.

This study focuses on developing copper oxide-based nanocomposites using plant extracts for photocatalytic applications. Curcuma amada leaf and Alysicarpus vaginalis leaf extracts were utilized alongside recycled copper precursors to synthesize photocatalysts via a green synthesis approach. Structural characterization through X-ray diffraction confirmed the formation of monoclinic CuO with reduced crystallite sizes due to plant extract incorporation. Fourier-transform infrared spectroscopy identified additional functional groups from the plant extracts, enhancing the material's properties. UV-Vis spectroscopy demonstrated increased light absorption and narrowed bandgaps in the nanocomposites, crucial for efficient photocatalysis under visible light. Morphological studies using FESEM revealed unique leaf-like structures in nanocomposites, indicative of the plant extract's influence on morphology. Photocatalytic degradation of methylene blue, rhodamine B, Congo red, and reactive blue 171 dyes showed enhanced performance of plant extract-modified CuO compared to without plant extract mediated CuO, attributed to improved charge carrier separation and extended lifetime. The effects of pH, catalyst dosage, and dye concentration on degradation efficiency were systematically investigated, highlighting optimal conditions for each dye type. Radical scavenger studies confirmed the roles of holes and hydroxyl radicals in the degradation process. Kinetic analysis revealed pseudo-second-order kinetics for dye degradation, underscoring the effectiveness of the nanocomposites. Overall, this research provides insights into sustainable photocatalytic materials using plant extracts and recycled copper, showcasing their potential for environmental remediation applications.

Microstructure, thermal and radiation shielding properties of aluminium‐silicon‐boron alloy prepared by mechanical alloying

AbstractThis 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.

Synthesis of Ag Doped ZnO Nanowire by Hydrothermal Method and its Characterization

This research is mainly focused over synthesizing zinc oxide (ZnO) nanowire (NW) and silver doped zinc oxide nanowires (Ag/ZnO) using two step hydrothermal method which comprises of seed layer deposition and hydrothermal nanowire growth step. Hydrothermally grown nanowires are of great significance. The synthesized nanowires were characterized by UV-Vis Spectroscopy (UV-Vis), X- ray Diffraction Spectroscopy (XRD), Energy Dispersive Spectroscopy (EDS), Field Emission Scanning Electron Microscopy (FE-SEM) and High-Resolution Transmission Electron Spectroscopy (HR-TEM). XRD pattern revealed as-synthesized materials are of crystalline nature having crystallite size of 166.27 nm and 42.32 nm for ZnO nanowire and Ag doped nanowire, respectively. Further confirmation was done by EDS, SEM and TEM. The microscopic images of SEM and TEM evidenced for successful fabrication of nanowires.

Mechanical and Structural Characterization of Resole Resin Composites Reinforced with Sabai Grass-Derived Cellulose Fibers

Cellulose fibers were extracted from Sabai grass (Eulaliopsis binata) using mechanical and chemical treatments. The grass was ground to ~250 µm powder and bleached with hydrogen peroxide and acetic acid. The bleached fibers were treated with 6% sodium hydroxide solution and incorporated into resole resin at various weight percentages to prepare the composites. The prepared samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and compressive strength tests. The XRD and FTIR showed a nanometric crystallite size of 3.84 nm and effective removal of non-cellulosic compounds, respectively, leading to a compressive strength increase from 15.60 MPa to 25.26 MPa at 3 wt.-% cellulose fiber. The compressive strength improved up to 3 wt.-% cellulose fiber, which however declined upon adding more filler. SEM revealed modified surface morphology in the composites with cellulose fibers.

Synthesis and Characterizations of BiFeO3 Nanoparticles for Photocatalytic Application

AbstractBismuth ferrite (BiFeO3) nanoparticles were synthesized using sol‐gel method and annealed at 450 °C, 550 °C, 650 °C, and 750 °C for 2 hours. The role of annealing temperature on structural, optical, magnetic, and dielectric properties of BiFeO3 nanoparticles was studied. XRD patterns of BiFeO3 nanoparticles confirm the rhombohedral structure with a mean crystallite size of 40 nm. The optical bandgap of the BiFeO3 nanoparticles increased from 1.9 eV to 2.02 eV with annealing temperature. From photoluminescence spectra, it was observed that the BiFeO3 nanoparticles showed a clear emission peak at 565 nm and its intensity decreased with annealing temperature. Magnetic properties of the BiFeO3 nanoparticles were studied at room temperature and different magnetic behaviours were found in BiFeO3 nanoparticles. The BiFeO3 nanoparticles exhibited ferromagnetism at low annealing temperatures and diamagnetic nature at high annealing temperatures. The AC conductivity studies showed that BiFeO3 nanoparticles possess a dielectric constant of 170 with the least dielectric loss. The BiFeO3 nanoparticles annealed at 750 °C were studied for photocatalytic properties and showed good photocatalytic activity in the visible region. A prominent absorption peak at 663 nm in absorption spectra due to MB and it confirm the utility of BFO as photocatalyst applications.

Comparative microstructural analysis of V2O5 nanoparticles via x-ray diffraction (XRD) technique

Vanadium pentoxide (V2O5) nanoparticles exhibit diverse properties and have been studied for a wide range of applications, including energy storage, catalysis, environmental remediation, and material enhancement. In this work, we have reported the synthesis of vanadium pentaoxide (V2O5) nanoparticles using hydrothermal method. Ammonium metavanadate (NH4VO3) was used as a source of vanadium. These syntheses were carried out at four different concentrations of vanadium source. The hydrothermal reaction was conducted at a temperature of 180 °C for a duration of 24 hours, followed by an additional 24 hours period of natural cooling. Four samples were annealed in air using a muffle furnace at 500 °C for five hours. The x-ray diffraction technique was used to study the structural aspects. A comparative analysis of the microstructure was conducted utilizing the Scherrer method, the Williamson–Hall method and its various models, size-strain analysis, and the Halder–Wagner method. The crystallite size and microstrain were determined using these distinct methods, revealing a systematic correlation between the crystallite size and microstrain obtained through the different techniques.

Biosynthesis of microrubble-shaped nanoporous Co3O4/rGO NCs using leaves extract of Neolamarckia cadamba and its antibacterial/antioxidant performance

Nowadays, the whole globe is paying great attention for the sustainable development, eco-friendly and economical production of nanostructures materials. With this motivation, the present work portrayed one-step ‘in-situ’ bioinspired green fabrication of Co3O4–reduced graphene oxide nanocomposites (Co3O4–rGO NCs) for the first time utilizing an aqueous leaf extract of Neolamarckia cadamba. As-fabricated NCs were characterized by several analytical and electron microscopic techniques viz. X-ray diffraction (XRD), Fourier Transform-Infrared (FT-IR), Energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), BET (Brunauer-Emmett-Teller), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) to evaluate their phases, structure, shape, composition, chemical state, porosity, optical and morphological aspects. The XRD study revealed a cubic spinel symmetry of NCs, while crystallite size estimated around 25 nm. TEM spectroscopy exposed an average particle size 8–10 nm of Co3O4 grown on the surface of reduced graphene oxide (rGO NCs), whereas SEM analysis showed sharped microrubble-shaped morphology. The formation of NCs by doping metal oxide with rGO through in-situ method were confirmed by XRD, EDS, Raman, and XPS spectroscopy. The BET study estimated the specific surface area and pore size of NCs as 98 m2/g and 8.9 nm respectively. The Co3O4–rGO NCs demonstrated an effective bactericidal activity against S. aureus, E. coli, K. pneumoniae, and B. subtillis. Prominently it was found that, a significant antibacterial activity seen against E. coli and S. aureus at a concentration 0.1 mg/100 µL may be due to scaffold morphology, nanoscale-structures and nanoporosity of the NCs. Due to receiving significant antibacterial activity, material’s molecular docking was assessed. Furthermore, an antioxidant activity of leaf extract and NCs was evaluated by DPPH method. An outstanding biological study of bioinspired NCs revealed that material could be used as a potent antimicrobial agent.

Enhanced Removal of Cd(II) Ions from Aqueous Media via Adsorption on Facilely Synthesized Copper Ferrite Nanoparticles

In this study, magnetic copper ferrite (CuFe2O4) nanoparticles were synthesized via the Pechini sol-gel method and evaluated for the removal of Cd(II) ions from aqueous solutions. PF600 and PF800 refer to the samples that were synthesized at 600 °C and 800 °C, respectively. Comprehensive characterization using FTIR, XRD, FE-SEM, HR-TEM, and EDX confirmed the successful formation of CuFe2O4 spinel structures, with crystallite sizes of 22.64 nm (PF600) and 30.13 nm (PF800). FE-SEM analysis revealed particle diameters of 154.98 nm (PF600) and 230.05 nm (PF800), exhibiting spherical and irregular shapes. HR-TEM analysis further confirmed the presence of aggregated nanoparticles with average diameters of 52.26 nm (PF600) and 98.32 nm (PF800). The PF600 and PF800 nanoparticles exhibited exceptional adsorption capacities of 377.36 mg/g and 322.58 mg/g, respectively, significantly outperforming many materials reported in the literature. Adsorption followed the Langmuir isotherm model and pseudo-second-order kinetics, indicating monolayer adsorption and strong physisorption. The process was spontaneous, exothermic, and predominantly physical. Reusability tests demonstrated high adsorption efficiency across multiple cycles when desorbed with a 0.5 M ethylenediaminetetraacetic acid (EDTA) solution, emphasizing the practical applicability of these nanoparticles. The inherent magnetic properties of CuFe2O4 facilitated easy separation from the aqueous medium using a magnet, enabling efficient and cost-effective recovery of the adsorbent. These findings highlight the potential of CuFe2O4 nanoparticles, particularly PF600, for the effective and sustainable removal of Cd(II) ions from water.

Synthesis and Characterisation of Nanocrystalline CoxFe1−xGDC Powders as a Functional Anode Material for the Solid Oxide Fuel Cell

The necessity for high operational temperatures presents a considerable obstacle to the commercial viability of solid oxide fuel cells (SOFCs). The introduction of active co-dopant ions to polycrystalline solid structures can directly impact the physiochemical and electrical properties of the resulting composites including crystallite size, lattice parameters, ionic and electronic conductivity, sinterability, and mechanical strength. This study proposes cobalt–iron-substituted gadolinium-doped ceria (CoxFe1-xGDC) as an innovative, nickel-free anode composite for developing ceramic fuel cells. A new co-precipitation technique using ammonium tartrate as the precipitant in a multi-cationic solution with Co2+, Gd3+, Fe3+, and Ce3+ ions was utilized. The physicochemical and morphological characteristics of the synthesized samples were systematically analysed using a comprehensive set of techniques, including DSC/TGA for a thermal analysis, XRD for a crystallographic analysis, SEM/EDX for a morphological and elemental analysis, FT-IR for a chemical bonding analysis, and Raman spectroscopy for a vibrational analysis. The morphological analysis, SEM, showed the formation of nanoparticles (≤15 nm), which corresponded well with the crystal size determined by the XRD analysis, which was within the range of ≤10 nm. The fabrication of single SOFC bilayers occurred within an electrolyte-supported structure, with the use of the GDC as the electrolyte layer and the CoO–Fe2O3/GDC composite as the anode. SEM imaging and the EIS analysis were utilized to examine the fabricated symmetrical cells.

Optimizing photocatalytic performance with Ag-doped ZnO nanoparticles: Synthesis and characterization

The development of nanotechnology has significantly impacted the improvement of photocatalytic performance of ZnO NPs. In this study synthesis of pure ZnO and Ag–ZnO nanoparticles via a co-precipitation method at varying Ag concentrations (1 %, 2 %, 3 %, 4 % and 6 %) to enhance their photo catalytic efficacy. X-ray diffraction (XRD) analysis estimates crystallite size which decreased by increasing Ag concentration, ranging from 30.6 nm (Pure ZnO) to 22.5 nm 6 % Ag-doped ZnO. Scanning electron microscopy (SEM) revealed decrease in particle size with increasing Ag content. UV–Vis spectroscopy indicating a narrowed band gap of optimal sample. Photocatalytic activity of the synthesized nanoparticles was evaluated using methylene orange (MO) dye degradation under light irradiation. The MO concentration exhibited a decrease with increasing irradiation time in the presence of photocatalysts. Recombination rate of NPs decreases by increasing the concentration of Ag i.e. 4%Ag dope ZnO NPs have lowest recombination rate and maximum degradation efficiency. FTIR analysis confirms the preparation of Ag-doped ZnO NPs. This improvement can be credited to the synergistic effect of Ag doping, leading to a narrowed band gap and potentially maximum degradation of MO by using Ag-doped ZnO NPs.

Synthesis and application of nanorod Bi2WO6/ZnO/rGO composite as a latent high-performance supercapacitor electrode

Bismuth Tungstate/Zinc oxide/reduced Graphene Oxide (Bi2WO6(BWO)/ZnO/rGO) nanocomposites with various ratios of rGO were fabricated utilizing a surfactant-driven hydrothermal process to investigate structural, morphological, and electrochemical properties as a potential electrode material. Compared with the BWO/ZnO/rGO(0.03 wt%) to BWO/ZnO/rGO(0.02 wt%) and BWO/ZnO/rGO(0.02 wt%) composite electrodes, the composite with the highest concentration of rGO with a particular capacitance demonstrates much greater capacitive performances(Cs) of 254.34 Fg−1 at 2 A/g with high cycling stability with capacitance retention of 79.67 % of the initial capacitance(Cs). A good rate capacity of 87.39 % at 5 A/g, 85.37 % at 10 A/g, and a 79.67 % reduction of its initial capacitance at an extreme charge/discharge current density of 20 A/g. The enhanced performance of BWO/ZnO/rGO composites suggested a potential material for supercapacitor electrodes. EDX result ensures the chemical purity level of synthesized nanocomposites according to the experiment design. The SEM results of the composites BWO/ZnO/rGO exhibit a 50–150 nm long short rod-like shape and an average diameter of approximately 50 nm. The XRD patterns of BWO, BWO/ZnO, and BWO/ZnO/rGO have crystallite sizes of 42.016, 44.845, and 59.784 nm respectively representing a gradual increase in size wt% of rGO increased in the composite.

Electrical and dielectric properties of PVA-doped NiGdxFe2-xO4 nanoferrite particles

NiGdxFe2-xO4 nanoferrites combined with polyvinyl alcohol (PVA) and having a distinct spinel phase composition (x = 0.01, 0.03, 0.05, 0.07, and 0.09) were effectively created. Several characterization approaches were used to study the structural, dielectric, and magnetic properties of the PVA-blended nanoferrites. The acquired X-ray diffraction pattern showed the spinel cubic structure. Crystallite sizes of 50, 44, 40, 35, and 31 nm were found in PVA-blended nanoparticles for x = 0.01, 0.03, 0.05, 0.07, and 0.09, respectively. When compared to the PVA-unblended nanoferrites, the PVA-blended nanoferrites showed insulating properties with an enlarged energy bandgap. Real and complex dielectric constants, as well as the measured dielectric loss, were all in the microwave range (frequency ∼ 1.88–5.93 GHz). At higher frequencies, the dielectric constant became constant after declining with frequency. From the PVA-blended nanoferrites impedance study, pseudocapacitance (x = 0.01, 0.03, and 0.05) and resistive behavior (x = 0.07 and 0.09) were investigated. The magnetization hysteresis plot of PVA-blended NiGdxFe2-xO4 nanoferrites revealed a mild ferromagnetic character. The PVA doping of the produced nanoferrites increased their saturation magnetization and had a considerable microwave absorption capacity. For the broadest range of electromagnetic radiation absorption, ferrite might be the perfect material. The addition of rare-earth ions to these basic ferrites results in a considerable modification of the ferrites’ electromagnetic characteristics.

Influence of plasma synthesis parameters on the magnetic, structural and photocatalytic properties of copper ferrite

CuFe2O4 cubic copper ferrite nanoparticles were synthesized by a new plasma method, the advantage of which is the short duration of processing and cost-effectiveness. To select optimal synthesis conditions, central compositional rotatable experimental planning was used. Using the methods of X-ray phase analysis, vibration magnetometry, electron microscopy, and UV spectroscopy, the sizes of crystallites, the intensity of peaks in X-ray diffraction patterns, dislocation density, saturation magnetization, coercive force, and the degree of degradation of 4-nitrophenol were determined. To study the effect of pH on the composition of the resulting copper ferrites, cyclic voltammetry was used. The kinetics of the ferritization process under the influence of a plasma discharge has also been studied. A mechanism for ferritization in the Cu2+-Fe2+-SO42--OH- system has been proposed.It was found that single-phase nanodispersed powders of cubic copper ferrites with a saturation magnetization Ms 78–93 Emu/g can be obtained by plasma treatment at 300 s and pH 12. Copper ferrite with an admixture of Cu2O is formed at pH = 8.The maximum values of the coercive force correspond to regimes in which the minimum dislocation density is observed. The saturation magnetization depends on the crystallite size. The crystallite size of the resulting powders is in the range of 225–500 A. The results showed that the processing time is the parameter that has the greatest impact on the structural and magnetic characteristics of copper ferrite; the pH of the reaction medium affects them to a lesser extent.

Structural, morphological, and optical investigations of Mn-doped LaAlO3 perovskite obtained by microwave-assisted combustion and rapid calcination at low temperature

In this work, LaAlO3 perovskite was doped with 1, 2, 3, 5, 8, and 13 mol% of Mn using the microwave-assisted combustion method. The powders produced were heat treated at 700 °C and 900 °C for 10 min in an adapted microwave oven and then characterized by Thermogravimetric analysis (TG/DTG) and Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Rietveld refinement, X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Ultraviolet–Visible Reflectance (UV–Vis), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The materials produced doped with the highest concentration of Mn (13 %) showed a single-phase reduced crystallite size compared to the pure sample. The unit cell volumes increased compared to the pure material, while the oxidation state of the dopant was mainly Mn3+. The refinement data for the volume of the different polyhedral that comprise the LaAlO3 unit cell revealed a local change at both sites, which may also indicate Mn substitution at the A site. The heat treatment temperature did not change significantly, demonstrating the method's efficiency in producing perovskites at temperatures and times below those reported in the literature. The morphology observed was porous and irregular agglomerates, and the bandgap was 2.90 eV.

Chitosan-coated manganese ferrite nanoparticles enhanced Rhodotorula toruloides carotenoid production.

The present study aims to analyze the interaction between Rhodotorula toruloides and magnetic nanoparticles and evaluate their effect on carotenoid production. The manganese ferrite nanoparticles were synthesized without chitosan (MnFe2O4) and chitosan coating (MnFe2O4-CS) by the co-precipitation method assisted by hydrothermal treatment. XRD (X-ray diffraction), Magnetometry, Dynamic Light Scattering (DLS) and FTIR (Fourier-Transform Infrared Spectroscopy), are used to characterize the magnetic nanoparticles. The crystallite size of MnFe2O4 was 16 nm for MnFe2O4 and 20 nm for MnFe2O4-CS. The magnetic saturation of MnFe2O4-CS was lower (39.6 ± 0.6 emu/g) than the same MnFe2O4 nanoparticles (42.7 ± 0.3 emu/g), which was attributed to the chitosan fraction presence. The MnFe2O4-CS FTIR spectra revealed the presence of the characteristic chitosan bands. DLS demonstrated that the average hydrodynamic diameters were 344 nm for MnFe2O4 and 167 nm for MnFe2O4-CS. A kinetic study of cell immobilization performed with their precipitation with a magnet demonstrated that interaction between magnetic nanoparticles and R. toruloides was characterized by an equilibrium time of 2h. The adsorption isotherm models (Langmuir and Freundlich) were fitted to the experimental values. The trypan blue assay was used for cell viability assessment. The carotenoid production increased to 256.2 ± 6.1 µg/g dry mass at 2.0 mg/mL MnFe2O4-CS. The use of MnFe2O4-CS to stimulate carotenoid yeast production and the magnetic separation of biomass are promising nanobiotechnological alternatives. Magnetic cell immobilization is a perspective technique for obtaining cell metabolites.

Investigation of the potential of zinc oxide-copper oxide nanocomposites as shielding against gamma ray, physical, and structural properties

The mass attenuation coefficient (μ/ρ) is examined in the experimental and theoretical way for five concentrations of ZnO–CuO nanocomposites. These samples have been synthesized by the Co-precipitation method. XRD investigation demonstrated an improvement in crystallite size by examining structure factors in a range (11.5–26) nm. The mass attenuation coefficient (μ/ρ) was measured experimentally at gamma-ray energies of radioisotopes 133Ba (356) keV, 22Na (511 and 1275) keV, 137Cs (662) keV, and 60Co (1173 and 1333) keV using narrow beam geometry NaI(Tl) detector. The samples were subjected to theoretical study using the Phy-X/PSD program for comparison with the experimental results. Total atomic cross sections (σt,a), electronic cross sections (σt,e), and effective atomic number (Zeff) were calculated using the obtained μ/ρ values. The findings demonstrate that there is generally good agreement between theoretical and experimental calculations, which supports the suitability of ZnO–CuO nanocomposites for gamma radiation shielding.

Effect of Zr, Sm and Gd Doped CoFe2O4 on Structural, Spectral and Magnetic Properties

In this work, cobalt composite nano ferrites with chemical formula CoZr0.05-xRExFe1.95O4 (x = 0 and 0.025 and RE = Sm, Gd) were prepared using sol-gel synthesis method and studied structural, optical and magnetic properties of them. The Rietveld assessment of XRD data validated the emergence of a single-phase cubic spinel configuration for all compounds. SEM has been used to study the surface morphology of the compounds. Energy gap has been estimated and the values are 2 eV, 1.8 eV and 1.6 eV for CoZr0.05Fe2O4, CoZr0.025Sm0.025 Fe1.95O4, and CoZr0.025Gd0.025 Fe1.95O4 compounds respectively. FTIR and Raman spectra confirmed the structure with the appearance of standard modes. The RE replacement in CoFe2O4 ferrites has an intense impact on magnetic properties. With the substitution of Sm3+ and Gd3+ ions in cobalt-zirconium ferrite, there is a reduction in saturation magnetization (55 emu g−1 of CoZr0.05Fe2O4 reduced to 25 emu g−1 for Gd3+ and to 29 emu gm−1 for Sm3+) as the size of crystallites decreases. A decrease in crystallite size correlates with an increase in the number of spin disorder occurrences in rare Earth-substituted cobalt-zirconium ferrite nanoparticles Further, the decrease in coercivity (2440 Oe of CoZr0.05Fe2O4 reduced to 720 Oe for Gd3+ and to 29 Oe for Sm3+ with rare Earth element doping is due to the crystallite size and large lattice distortion showed an enhancement of magnetocrystalline anisotropy field which effects a shift of resonance frequencies from higher frequencies which is good for the memory storage devices.

Synthesis, characterization, and azo dye degradation performance of mechanically alloyed Mg65Cu20Y13La2 nanocrystalline powders

This research describes the synthesis of the multicomponent Mg65Cu20Y13La2 alloy by mechanical alloying (MA) to investigate the influence of milling times on the microstructure of alloy and degradation performance of methyl orange. The structural evolution of this alloy was investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectrometry (EDX) techniques. The thermal behavior of the alloys was investigated by differential scanning calorimetry (DSC). The crystallite size of the Mg65Cu20Y13La2 alloys was calculated using the Debye Scherrer equation with broadening of the XRD peaks. The methyl orange degradation efficiencies of the Mg65Cu20Y13La2 alloys were evaluated by using ultraviolet–visible (UV–Vis) spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), and gas chromatography–mass spectrometry (GC–MS) techniques. The XRD and SEM results showed that the microstructure of the powders changed during MA. After 10 h milling time, three intermetallic phases were obtained as Mg2Cu2La, Mg24Y5, and Mg2Cu. The results also showed that a solid solution phase, α-Mg(Cu, Y, La), with an average crystallite size 21 nm was formed after 100 h milling time. DSC trace of the Mg65Cu20Y13La2 powders showed two exothermic peaks for the 10 h milling time, while it did not show any peaks for the 100 h milling time. Photocatalytic decomposition of the methyl orange solution by the Mg65Cu20Y13La2 alloy was evaluated by UV–Vis spectra with a decrease in absorbance at a wavelength of 465 nm. After a 20 min exposure, UV–Vis, FT-IR, and GC–MS analysis showed that the methyl orange samples were almost completely degradation by using the Mg65Cu20Y13La2 powders. The Mg65Cu20Y13La2 alloy exhibits a good reusability of 92% by the four cycle and a high efficiency was achieved in all the pH values in the range of 5–9. The results prove that the Mg65Cu20Y13La2 alloy is an efficient and promising material for dyeing wastewater treatment.