Zirconium based metal pretreatments have become widely used in recent years as a substitute for phosphate deposition on steel alloys and for chromate on aluminum alloys in industrial applications. The choice of a zirconium based intermediate layer follows from its ecologic sustainability − decreased water and energy consumption, vehicle weight reduction, and low byproduct generation during processing. Here we describe our investigations of a characterization method of converted metal oxide thin films deposited by a plasma method. The thin film composition was characterized by Rutherford Backscattering Spectroscopy (RBS) and Energy Dispersive Spectroscopy (EDS) before and after conversion by a zirconium-based pretreatment, revealing the formation of zirconia after treatment. The corrosion mechanism of the deposited metal oxide films was investigated using electrochemical analysis, confirming the susceptibility of the film to corrosion and the applicability of corrosion investigations. The results pointed to a better performance of the RBS in comparison to EDS.