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Amorphous LaNiO3 (a-LNO) and crystalline LaNiO3 (c-LNO) films were prepared by spraying an aqueous precursor solution of lanthanum and nickel chlorides on hot (450°C) fused silica substrates followed by annealing at high temperatures (550–850°C). Thermal analysis of a dried precursor indicated that a stable oxide phase is formed at 560°C with no distinct crystallization peak. Scanning electron microscopy (SEM) powered with energy-dispersive X-ray spectroscopy (EDX) of as-sprayed films showed rough surfaces with particulate-like deposits and incomplete pyrolysis chloride composition. No chloride contents were detected in annealed films. X-ray diffraction showed that films annealed at 550°C and 650°C were a-LNO and those annealed at 750°C and 850°C were c-LNO. The c-LNO phase was indexed as a single-phase perovskite structure with (110) orientation. SEM/EDX showed that a-LNO films have rough surfaces and c-LNO films have uniform crack-free smooth surfaces. Electrical properties measurements showed that c-LNO films have lower resistivity than a-LNO films and both types of LNO films have semiconductor resistant temperature dependence. The activation energy of electric conduction of a-LNO films was found to be much higher than that of c-LNO films. The optical transmittance and reflectance of the films were studied in the UV–visible–near IR range. The optical constants were obtained by modeling the measured transmission and reflection spectra. Because of the discrepancies in the morphology and in the physical properties of a-LNO and c-LNO films, the best fit modeling of transmission and reflection spectra was obtained by using different theoretical models and different geometrical configurations. While the Drude model accounting for larger carrier density was found to be significant for c-LNO, using the Bruggmann model and a configuration of a rough layer on top of a compact film was found to be significant for a-LNO. [ABSTRACT FROM AUTHOR]

Abstract: Corundum (hexagonal) structure indium tin oxide (h-ITO) nanocrystals have been synthesized by subjecting an aqueous solution of In and Sn chlorides (Sn/In 8wt.%) to a hydrothermal process followed by annealing at 450°C in forming gas for 1h. The annealing temperature was selected based on thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) of the dried precipitated powder, which showed a stable weight and phase at temperatures above 420°C. X-ray diffraction (XRD) patterns showed the formation of orthorhombic InOOH precipitates that is transformed, after annealing, into h-ITO nanocrystals with 32nm average crystal size. For nanostructure film deposition, dispersed sols of the prepared nanocrystals were spun coated on glass substrates. The films were densified by UV irradiation, whilst four-probe method was used to measure its sheet resistance. A sheet resistance as low as 10.6kΩ□ have been reached. Scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the films have high surface roughness and nanopores. The transmittance spectra of the nanostructure films were measured in the UV–vis–NIR wavelength range. In addition to its low resistivity, nanostructure h-ITO films showed a wide range of transparency. [Copyright &y& Elsevier]