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In the present work, mechanical, tribological, and electrochemical behaviors of Al Alloy 6061–(0–10) % B4C–(0.25–1.2) % graphene nanoplatelets (GNPs) composites, prepared by a combination of solution mixing and powder metallurgy, were investigated. Properties such as hardness, compressive strength, wear rates, and coefficient of friction (COF) were used to investigate the effects of GNPs on mechanical and self-lubricating tribological behavior. The corrosion resistance of composites was investigated using potentiodynamic polarization and electrochemical impedance techniques. Scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), and EDS mapping were employed to study the distribution, the fracture profile, and wear mechanism. The AA 6061–10% B4C–0.6% GNPs composites exhibited sharp increase in hardness and compressive strength and significant decrease in wear rates and COF. However, for GNPs contents exceeding over 0.6 wt%, mechanical properties and wear performances deteriorated. Pulling out of sheared pultruded GNPs was observed during the fracture of composites. Worn surfaces of GNPs-containing composites showed the smeared graphene layer with some macro-cracks exhibiting delamination wear. It was found that the corrosion inhibition efficiency of GNPs was more pronounced in H3BO3 environment than in NaCl solution.

Nitrogen implanted III-V compounds semiconductors have attracted a great deal of attention of the research community due to their interesting fundamental physical properties and potential applications in optoelectronic devices. A small amount of nitrogen incorporation in gallium arsenide (GaAs) causes significant reduction in the band gap energy of fabricated alloys. In this study the GaAsN layer was prepared by implantation of nitrogen ion on thick GaAs wafer and the samples were thermally annealed for studying annealing effects. The structural, compositional and optical properties have been investigated by X-Ray Diffraction (XRD), Rutherford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), Photoluminescence (PL) and Photo-thermal Deflection Spectroscopy (PDS). The results reveal that the samples prepared with higher implantation dose and annealed at higher temperature exhibit strong optical signal of GaN, while the samples annealed at lower temperature show weak optical signal. Furthermore in PDS spectra, the band gap reduction was observed indicating the diluted nitrogen content in GaAs. We have demonstrated that annealing conditions and implanted nitrogen doses could be helpful to achieve the desired variation in band gap and low physical damages on surface.

Here, the structure-dependent electronic, thermal, and transport properties of nanostructured thallium telluride (Tl8Pb x Sb2−x Te6) through controlled variation in Pb and Sb (x = 1.96, 1.97, 1.98, 1.99) concentrations have been investigated. In the temperature and concentration-dependent electrical conductivity measurements, the highest electrical conductivity 131.96 × 103 Ω − 1 m − 1 at 300 K was measured for x = 1.99 and the maximum observed Seebeck value for the optimized Tl8Pb1.96Sb0.04Te6 nanoparticles was 110.7 μV/K at 550 K. Such an increased value of the Seebeck coefficient led to the achievement of a significantly improved high-power factor, which was found to be increasing with temperature and decreasing with the increase of Pb concentration. The density functional theory calculations performed for Pb and Sb co-doped Tl5Te3 resulted in the enhanced σ e and S with a significant reduction in electronic thermal conductivity (κ e ) and is found consistent with experimentally measured κ e . The highest ZT = 0.35 and 0.18 were recorded experimentally and theoretically for Pb and Sb co-doped in Tl5Te3 nanoparticles.

Crystalline boron carbide (B4C) powder was synthesized by carbothermal reduction of condensed boric acid-cellulose product and effect of structural homogeneity of precursor on low-temperature synthesis of B4C was investigated on basis of cellulose-derived structural development. The formation of condensed products was confirmed by FTIR and TGA analyses. The pyrolyzed products of cellulose precursor at 400 °C for 2 h were composed of fine dispersion of carbon fibers with B2O3 particles. The formation of carbon fibers favored conversion kinetics of B4C synthesis. The formation of crystalline B4C started and completed at 1100 and 1200 °C, which was one of the lowest temperatures reported for polymeric precursor route. Morphology of synthesized B4C transformed from polyhedral to equiaxed as synthesis temperature was raised from 1150 to 1200 °C. Nitrogen physisorption measurements revealed that synthesized B4C powders had mesopores with high surface area indicating large interfacial area of B2O3/carbon fibers resulting in more nucleation sites.

Cadmium selenide (CdSe) thin films were deposited on the glass substrates by using the resistive thermal evaporation method in the vacuum chamber. The effect of antimony doping on the physical properties of CdSe thin film has been investigated. The structural and surface properties such as lattice parameters, grain size, microstrain and dislocation density of the thin films were characterized by X-ray diffraction (XRD) technique. The compositional properties were studied by the mean of Rutherford backscattering (RBS) and UV–Vis–NIR spectrophotometer used to determine the refractive index, absorption coefficient and optical energy band gap of thin films. The FTIR absorption spectra confirmed the presence of CdSe vibrational mode in the range 400 cm−1 to 700 cm−1. The electrical conductivity of the films was carried out with the help of impedance analyzer, which has been increased up to 1% on Sb doping. The transmission has been reduced up to 18% with the increase in Sb doping and shifted toward lower wavelengths

Thin films of cadmium sulfide with very well defined preferential orientation and relatively high absorption coefficient were fabricated by thermal evaporation technique. The research is focused to the fabrication and characterization of the compositional data of CdS thin films obtained by using X-ray diffraction, scanning electron microscope along with energy dispersive X-ray spectroscopy. The optical properties were studied by using a UV-VIS-NIR spectrophotometer. The effects of silver-doping by ion exchange process on the properties of as-deposited CdS thin films have been investigated.

Thin films of CdS were fabricated by close spaced sublimation technique under vacuum of ∼10−5 mbar at a source temperature of 550 °C for various periods of time. These as-deposited thin films were immersed into Cu (NO3)2 solution at 80 ± 5 °C for variety of time to ensure Cu doping. The structural, surface, optical and electrical analyses were completed with the help of X-Ray Diffraction, Scanning Electron Microscope with Energy Dispersive X-Ray, UV-VIS-NIR Spectrophotometer and Hall Measurement System respectively. The transmittance of as-deposited sample is reduced from 80% to 30% with increasing copper immersion time. The mobility increased from 6.67 × 101 to 1.15 × 103 cm2/Vs due to the change in the carrier concentration.

Closed space sublimation (CSS) technique was used to deposit pure (99.99%) zinc selenide(ZnSe) powder on to glass substrates for fabricating the ZnSe thin films. The temperatures of source, substrate and the deposition time were optimized to deposit thin films of different thicknesses. Silver (Ag) was used as a dopant by ion exchange process in the ZnSe thin films. The structural analysis showed that as-deposited ZnSe thin films were polycrystalline having preferred orientation (111) direction. Micro structural parameters such as crystallite size, lattice parameter were determined using X-rays diffraction (XRD). Grains boundaries, roughness on surface and the grain density of the thin film samples were measured by scanning electron and atomic force microscopy before and after Ag doping.As-deposited, Ag-doped ZnSe samples before and after annealing were optically characterized by spectrophotometer in ultra violet, visible and infrared regions. The energy band gap of as-deposited ZnSe thin films for varying thicknesses were ranging from 2.62-2.67 eV which was reduced after Ag doping.The electrical properties showed that as-deposited thin films were highly resistive of the order of 10 -cm and after Ag immersion, it was reduced to 1 -cm. Deposition parameters and Ag doping 8

Sodium benzoate (SB) is used for the first time to inhibit the corrosion of Al6061-B4C composites in H3BO3 and NaCl solutions. Al6061100−x –x wt% B4C (x = 0, 5, and 10) composites are manufactured by a powder metallurgy route. The corrosion inhibition efficiency of SB is investigated as a function of the volume fractions of B4C particles by using potentiodynamic polarization and electrochemical impedance techniques. Without the use of an inhibitor, an increase of the B4C particles in the composite decreases the corrosion resistance of Al6061-B4C composites. It is found that SB is an efficient corrosion inhibitor for Al6061-B4C composites in both investigated solutions. The corrosion inhibition efficiency of SB increases with an increase in B4C content. Since SB is an adsorption type inhibitor, it is envisaged that an extremely thin layer of molecules adsorbs onto the surface and suppresses the oxidation and reduction. It is found that the inhibitor effect of SB is more pronounced in a H3BO3 environment than in NaCl solution. Further, the mechanism of corrosion inhibition by SB is illustrated by using optical and scanning electron microscopy of corroded samples. It is found that the adsorption of benzoate ions on the Al surface and its bonding with Al3+ ions forms a hydrophobic layer on top of the exposed Al surface, which enhances the protection against dissolved boride ions.