This study focuses on the modulation of synthetic parameters in order to influence the size, structure, composition and arrangement of cobalt nanoparticles. The synthetic procedure followed is the thermo-decomposition method of cobalt precursors in the presence of organic solvents and surfactants. Particles isolation and oxidation rate are determined by the mechanism of cobalt precursor degradation as well as to the combined use of different surfactants. The reaction conditions are also responsible for the final product composition. Inert gas environment produces fcc Co nanoparticles whereas open air conditions or the presence of oxidizing agents leads to CoO. Oxidation is followed by diminishing ferromagnetic features contrary to metallic nanoparticles that present enhanced magnetic properties compared to the bulk.
