25 research outputs found

    Self-organized nanoclusters in solution-processed mesoporous In-Ga-Zn-O thin films

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    International audienceSelf-organized nanoclusters were obtained in annealed solution-processed In-Ga-Zn-O thin films. STEM and anomalous grazing incidence small-angle X-ray scattering (GISAXS) reveal the formation of nanometer-sized nanoclusters together with the spontaneous creation of a mesopore pattern

    Effect of thermal annealing on the morphology of sol–gel processed barium strontium titanate thin films: Consequences on electrical properties

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    International audienceThe link between the morphology and the electrical properties of the sol–gel processed Ba0.7Sr0.3TiO3 thin films is investigated. Previous studies have not fully explained the differences in growth morphology as a function of the elaboration conditions. The thin films were investigated by Grazing Incidence Small-Angle X-ray Scattering (GISAXS), x-ray diffraction, and scanning electron microscopy. More precisely, prototype films were studied as a function of the annealing temperature: at low temperatures (140 °C–200 °C) by in situ GISAXS and at high temperatures (600 °C–800 °C) by ex situ GISAXS. At ∼150 °C, self-organized domains with a preferential distance of approximately 14 nm are formed. At high annealing temperatures, the growing domains become either nanoparticles or pores with a preferential distance of approximately 85 nm at 600 °C. This growth evolution is successfully explained by a general model based on convection and evaporation. With thermal annealing, the characteristic lengths parallel to the surface increase due to convection and the characteristic lengths perpendicular to the surface decrease due to evaporation. In addition, two types of annealing were investigated at 700 °C. For annealing after each other layer, a growth with vertically shifted particles occurs with no ferroelectric behavior. On the contrary, for annealing after each deposited layer, a columnar growth occurs and a ferroelectric hysteresis loop is obtained. The ferroelectricity of the sol–gel barium strontium titanate thin films is definitely linked to the complete removal of organic constituents leading to columnar growth

    Modification of the Selected Method for the Determination of Serum Iron. Substitution of Bathophenanthroline by Ferene S

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    The previously selected method (1977) for the measurement of iron in human serum has been modified by the working group on Iron and Iron-Transport Proteins (Societe Francaise de Biologie Clinique). Ferene S is used as the chromogen, it is more sensitive and cheaper than bathophenanthroline. The sample size has been reduced from 2 to 0.5 ml. No interference could be shown with high concentrations of bilirubin, copper or hemoglobin
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