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CdSe1-xSx (x= 0.3, 0.4 and 0.6) thin films were deposited on quartz and silicon substrates by the method of high-frequency magnetron sputtering. The chemical composition analysis and crystal structure refinement was examined with using X-ray fluorescence spectroscopy and X-ray diffraction data. CdSe1-xSx thin films crystallizes in hexagonal structure (structure type – ZnO, space group P63mc (No. 186)). The lattice parameters (a, c and V), crystallite size (D), strain (ε), dislocation density (δ) and the texture coefficient TC(hkl) was estimated from X-ray diffraction analysis. Units-cell parameters decrease with increasing S content in CdSe1-xSx thin film.

Nickel aluminate (NiAl2O4) nanoparticles were synthesized using sol-gel method with auto-combustion. The prepared nanoparticles were made into four parts and calcinated at 700, 900, 1100 and 13000C and taken up for the present study. The taken-up nanoparticles were characterized using powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersion X-Ray Spectroscopy (EDS), Fourier Transform and Infrared (FT-IR) spectroscopy and UV-Vis spectroscopy techniques. The X-ray diffraction patterns confirmed the spinel structure and Fd3m space group. Scherrer formula was used to calculate the crystallite size and found in the range 5.78 to 20.55 nm whereas the lattice parameter was found in the range of 8.039 to 8.342 Å. The average grain size was found in the range 142.80 to 187.37 nm whereas interplanar spacing was found in the range of 2.100 to 2.479 Å. The FTIR spectroscopy showed six absorption bands in the range 400 to 3450 cm-1 and confirmed the spinel structure. The optical band gap (Eg) was decreased with calcination temperature and found in the range 4.2129-4.3115eV.

Nanocrystalline La0.7Sr0.15Ca0.15MnO3 (LSCMO) manganites were prepared by the combustion process and heated to various annealing temperatures (TA) to get various sized crystallites. The X-ray diffraction (XRD) patterns provided evidence that a Rhombohedral structure with space group was formed. Additionally, an increase in the size of the crystallites was observed, from 15.64 to 36.78nm, as the temperature (TA) increased from 700℃ to 1300℃. The FESEM micrographs revealed that homogeneous with porosity. The FTIR spectra showed five absorption peaks. The Optical energy gap of LSCMO nanocrystalline is decreased from 3.51 to 3.28 eV as annealed temperature raised, reveals that the LSCMO nanoparticles are semiconductor in nature. Room temperature Raman spectra of LSCMO nanoparticles demonstrate a notable reliance on annealing temperature. When the Raman modes were analysed with respect to TA, it was observed that the Raman vibrational phonon mode below 200cm-1 (A1g) and four modes (Eg) in the range 200-800cm-1 displayed significant displacements and widening, which were associated with oxygen sublattice distortion. Considerable changes were observed in both the intensity and full width half maximum (FWHM) of the five Raman modes as the annealing temperature increased. Magnetic behaviour using M-H loop at room temperature were measured by the Vibrating sample magnetometer revealed that gradation of saturation magnetization as the function of annealing temperature. Hence there is a remarkable crystallite size effect on optical and magnetic properties of LSCMO nanocrystallites.

CaFeO2.5 samples were synthesized by solid solution, mirror furnace and Sol-gel methods. The effect of the synthesis method on the behavior structure was investigated. Phase structures are comparatively characterized and studied by means of X-ray powder diffraction. Experimental results have revealed that the synthesis method has a strong influence on the structure of the studied compounds. All samples obtained by the three methods are crystallized in the Pnma orthorhombic system. We obtained the best results in the case of the Sol-gel technique. In the Sol-gel method, the lattice parameters obtained are a=5.41631 Å, b= 14.73899 Å and c=5.58790 Å. Also, the value of the average crystallite size D=52.03 nm and the dislocation density δ=3.69x1010/cm². Since the values ​​of the lattice parameters in this method were the smallest of the three methods, which exhibiting a weak shrink of the volume compared to the solid solution and mirror furnace one. This shrinking is a natural result of the decrease in the value of the average crystallite size and the increase of dislocation density, with a reason for the inverse relationship between them. This allows us to conclude the importance of the Sol-gel method for obtaining CaFeO2.5 nanoscale compound.