Formation and photo-electrochemical characterization of anodic films on valve-metal alloys

The formation of anodic films on valve metals alloys has been studied as a function of alloy composition and anodizing conditions. Photocurrent Spectroscopy technique (PCS) has been used to determine the band gap (E g) and the flat band potential (Vfb,) of oxides grown on these alloys. The formation of insulating-like or semiconducting oxide films has been evidenced as a function of initial alloys composition. The composition of "mixed oxide" has been related to the measured optical band gap values on the basis of experimental results and previous proposed correlation.