Formation and Crystallization of Anodic Oxide Films on Sputter-Deposited Titanium in Potentiostatic and Potential-Sweep Modes

Sputter-deposited titanium substrates were anodically treated in sulfuric acid solution both in potentiostatic and potential-sweep modes. The morphology, crystallization, chemical compositions and electrochemical properties of anodic titanium oxide films were detected by AFM, SE, Raman spectra, XPS and EIS. The formed anodic films are smooth and homogeneously crystallized, and that the potentiostatically grown film is slightly thicker and less crystalline than the potentiodynamically formed film. Moreover, a comparison of the structure and properties of the anodic oxides films formed on the mechanical-chemical polished bulk titanium and the sputter-deposited titanium substrates is also presented. The titanium substrates can largely influence the properties of the formed anodic films. A more smooth and compact titanium oxide film could grow on the sputter-deposited titanium substrate, which is unfavorable to the ionic migration through the film and delays the film growth and crystallization.