Synthesis and Investigation of Cobalt Containing Nanoparticles Morphology

The aim of this work is to develop methods of synthesis of stable monodisperse cobalt sol by the method of chemical reduction and obtain cobalt thin films on a silicon substrate, investigate their morphology and geometrical characteristics. Cobalt acetate was used as a precursor in this study, ascorbic acid was used as a reducing agent, the synthesis was carried out in an alcoholic medium. The resulting sol was studied by the method of photon correlation spectroscopy. Analysis of the data of the photon correlation spectroscopy revealed the presence of two fractions in a sample with an average hydrodynamic radius of the smaller fraction of about 3.9 nm and the larger one - 278 nm. Thin cobalt films were obtained by the method of drying the sol and method of rotating substrate coating. The obtained films were studied by the methods of energy dispersive analysis and atomic force microscopy. Analysis of AFM images of the film surface allowed us to make the conclusion about the shape and size of cobalt nanoparticles. Investigation of the morphology of nanoparticles deposited on the silicon substrate Co showed that the cobalt particles obtained by the method of drying sol films have a form of an elongated semi-ellipsoid with average typical dimensions of 50 to 350 nm and a height of 150 to 900 nm. The films obtained by method of deposition on a rotating substrate formed by particles have a shape of ellipsoidal sector with typical dimensions of 200 to 450 nm and a height of 10 to 50 nm.

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