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In the present study, a straightforward, surfactant-free working approach was successfully used to synthesize vanadium pentoxide (V2O5) nanoparticles. The effect of annealing on the morphological, structural, and optical properties of synthesized nanoparticles was investigated using Field emission scanning electron microscope (FESEM), Energy dispersive x-ray analysis (EDAX), X-ray diffraction (XRD), Diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Using XRD analysis, orthorhombic polycrystalline V2O5 nanostructures were identified. Based on structural analysis, V2O5 nanoparticles preferentially align in the peak direction (010) at annealed temperatures of 400 °C, 500 °C, and 600 °C. The surface morphology investigations revealed that increasing the temperature causes an increase in the size of particles and thickness. The characteristic vibration mode of the prepared nanoparticles was identified by Raman spectroscopy. The FT-IR spectra verified the occurrence of V–O functional groups and the formation of V2O5 nanoparticles. An increase in annealing temperature was found to decrease the optical band gap, which was reported to be between 2.24 and 2.15 eV. V2O5 nanoparticles annealed at 500 °C give the best results, obtaining the highest photocurrent at 5.43 nA, responsivity of 1.08 µA/W, and detectivity of 3.14 × 108 Jones beneath white light with a 1 V bias, according to an evaluation of the time-dependent photo-response features of all detectors. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and comprehensive characterization of Fe3Se4 and Fe7Se8 nanoparticles using various techniques. The synthesis utilized the solid-state reaction technique, followed by thorough characterization using X-ray diffraction analysis to determine structural parameters like crystallite size and lattice constant. Field Emission Scanning Electron Microscopy revealed granular formations with average particle sizes of approximately 147, 189, and 222 for Fe3Se4, 4c-Fe7Se8, and 3c-Fe7Se8 nanoparticles, respectively. Thermogravimetric Analysis demonstrated the thermal stability of the materials up to 304, 386, and 384 °C, with subsequent weight losses for Fe3Se4, 4c-Fe7Se8, and 3c-Fe7Se8 nanoparticles. Dielectric spectroscopy tests across a broad frequency range revealed non-Debye-type responses, indicating complex relaxation phenomena. A thorough analysis of dielectric characterization is comprehensively presented in this paper. [ABSTRACT FROM AUTHOR]

Iron oxides have found a large number of applications in fields ranging from biomedical to space science. Amongst all iron oxides, the most favored is Fe3O4 owing to high saturation magnetization, biocompatibility, and cost-effectiveness. The Fe3O4 has an inverse spinel structure with colors ranging from dark brown to black. In this research paper, the Fe3O4 and Co-doped Fe3O4 nanoparticles were synthesized by co-precipitate method. The X-ray diffractometer (XRD), Scanning electron microscopy (SEM), EDX and RAMAN spectroscopy analysis confirm the formation of synthesized nanoparticles. From UV visible, the optical properties are studied and it is found that after doping of Co, the band gap had increased, and the electrical property of doped Fe3O4 goes towards the dielectric behavior. From the vibrating sample magnetometer (VSM), magnetic properties are studied. By Gouy’s balance susceptibility was determined and values calculated, are in good agreement with the susceptibility calculated by VSM. The temperature-dependent conductivity was assessed using the four-probe method. The degradation of dye like methyl orange with the synthesized nanomaterials was studied. [ABSTRACT FROM AUTHOR]

Epoxy nano-magnetic composites exhibit remarkable and promising properties by synergistically combining the properties of epoxy resin and magnetic nanofillers. The current study deals with the synthesis of Fe3O4, NiFe2O4, and CoFe2O4 nanoparticles and their respective nanoparticles-doped epoxy composites, as well as the structural, optical, and dielectric characterization of the resultant nano-composites. To investigate the surface morphology of the synthesized nanoparticles, field emission electron microscopy (FESEM) analysis was employed. By measuring electron diffraction spectroscopy (EDS), the presence of various chemicals was verified. X-ray diffraction (XRD) was used to determine the structural details of the synthesized nanoparticles and nanoparticles-doped epoxy composites. The structural chemistry and surface functionality of the nano-epoxy composites were investigated using Fourier transform infrared spectroscopy (FTIR). The magnetic properties of the synthesized nanoparticles and nanoparticles loaded epoxy composites were also studied using a vibrating sample magnetometer (VSM). UV–visible reflection spectroscopy was also carried out to find the optical properties of the synthesized nanoparticles, neat (undoped) epoxy, and nanoparticles-doped epoxy composites. Dielectric spectroscopy measurements of nanoparticles-doped epoxy composites were performed using an Agilent E4980A precision LCR (Inductance Capacitance Resistance) meter with an Agilent 16451B-test fixture LCR and vector network analyzer (VNA) in the frequency span of 10 kHz to 2 MHz and 200 MHz to 20 GHz, respectively. The influence of the synthesized nanoparticles on the neat (undoped) epoxy composites and the results in view of future applications are fully discussed. [ABSTRACT FROM AUTHOR]

Epoxy nanocomposites exhibit remarkable characteristics by synergistically integrating the characteristics of epoxy resin with the unique properties of nanoparticles. This study focuses on the incorporation of ZnO and TiO2 nanoparticles into epoxy composites and investigates their impact on dielectric properties. A three-dimensional crosslinked structure was formed using Bisphenol-A epoxy resin and amine hardener. Dielectric spectroscopic assessments of the nanoparticle-doped epoxy composites were conducted over a frequency range of 20 Hz to 2 MHz and extended to 200 MHz to 20 GHz. The research provides a detailed analysis of the influence of ZnO and TiO2 nanoparticles on pristine, undoped epoxy resin. We present Regression analysis which is a useful tool for predicting the dielectric constant of intermediate frequency because it can save time and resources. Experiment data from tests show that using the XGBoost regression analysis can result in a 60% reduction in both time and resource requirements. [ABSTRACT FROM AUTHOR]

A356 Al alloy containing 7% Si and 0.3% Mg is widely used in automobile and aircraft industries due to excellent castability, good corrosion resistance and good pressure tightness. The present investigation was undertaken to explore the possibilities of rare earth metal additions primarily as modifiers of eutectic silicon and secondarily beneficial alloying element. In the present study, the effect of rare earth addition and stirring on the mechanical properties of a cast A356 alloy was studied. Alloy was casted by addition of 0%, 0.5 wt%, 1.5 wt% rare earth along with 0, 400 and 600 rpm of stirring speed. Microstructural characterization of the casted A356 alloy was carried out by means of Optical Microscopy and its phases were detected by XRD. Mechanical characterization was based on tensile and hardness tests. Inclusion of rare earth along with stirring gives grain refinement and increases the strength of the as-cast alloy. Optimal rare earth addition was found to be 0.5% at 600 rpm of stirring speed. Addition of rare earth causes formation of intermetallic compound as observed in XRD and stirring results in size reduction of dendrites and desegregation of Si needles present in A356 alloy. [ABSTRACT FROM AUTHOR]

Abstract: The dislocation density and microhardness of Bi2Te3−x Se x (x=0–0.3at% Se) grown by the zone melting method have been investigated. We also have got the whiskers of Bi2Te3−x Se x at the end of ampoule during the growth process. SEM was characterized for surface analysis of the grown whisker. The length of the grown whiskers was around 10mm in the direction of the crystallographic c-axis. Concentric pairs of dislocation triangle were observed on the as-grown surfaces of short hexagonal prisms. A systematic study of dislocations in these crystals was carried out by the chemical etching technique. Dislocation etching was achieved on all crystal planes examined using a saturated solution of citric acid and nitric acid as the etchant. The dislocation etchant has been found to give reproducible etch-pits on the cleavage surface. The use of citric acid and nitric acid proved to be especially advantageous for the basal plane, producing etched pits suitable for dislocation etch pit counting. The effects of Se doping, annealing and quenching on the mechanical properties have also been studied on the (001) faces of Bi2Te3−x Se x . [Copyright &y& Elsevier]