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The synthesis of nanoparticles has great control over the structural and functional characteristics of materials. In this study, CeO2 and Ni–CeO2 spherical nanoparticles were prepared using a microwave-assisted method. The prepared nanoparticles were characterized via thermogravimetry, X-ray diffraction (XRD), Raman, FTIR, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and cyclic voltammetry (CV). The pure CeO2 sample exhibited a flake-like morphology, whereas Ni-doped CeO2 showed spherical morphology with uniform shapes. Spherical morphologies for the Ni-doped samples were further confirmed via TEM micrographs. Thermogravimetric analyses revealed that decomposition varies with Ni-doping in CeO2. XRD revealed that the peak shifts towards lower angles for the Ni-doped samples. Furthermore, a diamagnetic to ferromagnetic transition was observed in Ni-doped CeO2. The ferromagnetic property was attributed to the introduction of oxygen vacancies in the CeO2 lattice upon doping with Ni, which were confirmed by Raman and XPS. The pseudo-capacitive properties of pure and Ni-doped CeO2 samples were evaluated via cyclic voltammetry and galvanostatic charge–discharge studies, wherein 1 M KOH was used as the electrolyte. The specific capacitances were 235, 351, 382, 577 and 417 F g−1 corresponding to the pure 1%, 3%, 5% and 7% of Ni doped samples at the current density of 2 A g−1, respectively. The 5% Ni-doped sample showed an excellent cyclic stability and maintained 94% of its maximum specific capacitance after 1000 cycles. [ABSTRACT FROM AUTHOR]

Highly oriented vanadium pentoxide (V2O5) thin films were grown by electron beam (EB) evaporation on glass substrates at 473 K. V2O5 thin films were coated with various thicknesses (≈800–1200 nm) by varying the distance from the source and substrates. The influence of film thickness on its physical properties was deeply studied by various characterization techniques. XRD studies were performed to investigate the structural confirmation and preferential lattice orientation of EB evaporated films. The Voigt profile method was used to estimate the microstructural parameters and to elaborately discuss its dependency on film thickness. SEM micrographs perceived that the prepared films were nearly homogeneous with densely packed morphology. AFM topographical images depicted the nanograins on the surface of the films. Raman spectra confirmed the formation of the α-V2O5 polymorph without secondary phase formation. From the optical absorption data, the indirect optical band gap ‘Eg’ was found to be 2.36 eV for V2O5 thin film with higher thickness. Optical constants such as refractive index (n), extinction coefficient (k), optical conductivity (σ) and dielectric constants (ε) were evaluated using an approximation protocol developed from well recognized procedures using the data obtained from the UV-Vis spectroscopic technique. The luminescence property variations were observed by photoluminescence (PL) spectroscopy and it has elucidated the role of film thickness in the EB evaporated V2O5 films. The Hall mobility and carrier density were found to increase with film thickness. [ABSTRACT FROM AUTHOR]

The etching process of Porous Silicon has been carried out using an electrochemical oxidation technique. Oxidized samples were immobilized with -Leucine, DL-Iso Leucine and DL-Nor Leucine solutions. Surface morphology and optical properties of the samples have been analyzed using scanning electron microscopy and optical absorption analysis techniques respectively. The bonding characteristics on the surface before and after amino acid deposition have been studied using fourier transform infrared spectroscopy. Photoluminescence spectroscopy was employed to determine the enhancement in wavelength shift of the etched porous silicon. [ABSTRACT FROM AUTHOR]