CARACTERIZACION SUPERFICIAL DE PELICULAS DE OXIDOS DE Co y Co-Fe SUPERFICIAL CHARACTERIZATION OF Co AND Co-Fe OXIDE FILMS

In this work the optical and chemical characterizations of films to be used as selective materials for the photothermal conversion of solar energy are presented. Thin films of Co and Co-Fe oxides were prepared by spray pyrolysis on steel substrates. The experimental conditions of preparation are described. The solar optical properties were evaluated from measurements of the spectral reflectance of the samples in the UV-Vis and near-mid-infrared ranges. Atomic Force Microscopy was used to determine the surface morphology and the roughness parameter of the samples. An XPS study was done in order to find the chemical composition of the surface. Finally, by modeling the results of spectroscopic ellipsometry measurements, structures for the distinct layer-substrate systems are proposed to fit the experimental data. From this model, the optical constants of the thin films were determined as a function of wavelength in the visible range.