In this paper, electrochemical methods were combined with electrochemical impedance spectroscopy (EIS) measurements as well as the ellipsometric response in order to study the electrochemical behavior of Sb in a wide range of conditions for oxide growth. Different electrolytes (phosphate, sulphate and chloride) in a wide range of pH and concentration were employed. Nature of the cation was also analysed. In addition, the morphology of the anodic films was obtained by AFM.
The anodic growth is explained in terms of the ?high-field? migration model and the voltammograms are simulated for this model taken into account homogeneous or preferential chemical dissolution processes coupled with the growth.
The impedance spectra show an inductive response at intermediate frequencies aside from the capacitance and resistance corresponding to the dielectric properties of the film, which is associated with the accumulation of negative surface charge at the oxide/solution interface [2]. This effect is also strongly dependent on pH and cation nature.
AFM images reveal that morphology of oxide films is dependent on concentration, polarization time and electrolyte. Porous films are obtained in chloride solutions.
