Anodic oxidation of titanium: Mechanism of non-stoichiometric oxide formation

Influence of Structure Transformations over the Growth and Semiconductor Properties of Ti Anodic Films in 0.1 M NaOH

“…In a similar way to other valve metals (14,22), the N d does not depend on the formation time ( Figure 5). The values of N d are in the same order of magnitude to those reported in the literature for Ti anodic films (1)(2)7). The N d depend exponentially with the E f ; the exponential function used to fit this behavior is shown in equation [4], this equation presents similar values to that obtained in other valve metals (14,22).…”

“…This different behavior may be due to the characteristics of Ti oxide film, which allows the electrochemical identification of different species formed during the growth of passive film (ie TiO, Ti 2 O 3 , TiO 2 ) (2-6). Then, for low E fb the mix of Ti 2 O 3 and TiO 2 (2,(4)(5)(6), may predominate and when E f becomes more positive, the proportion of TiO 2 respect Ti 2 O 3 increases, may be with the formation of intermediary oxides (Ti 2 O 3 ·mTiO 2 , 1 ≤ m ≤ 4) as reported in literature (2)(3)(4)(5)(6)(7)(8); and finally, for high E f the TiO 2 predominates in proportion. These results confirm that the E fb is sensitive to the structure of the semiconductor, varied either when the material is doped (24) or when it is mixed with other compounds (25).…”

“…Metikoš-Huković and Ceraj Cerić (7) have studied Ti oxide films in different media, using photopolarization, they proposed that the composition of the Ti oxide film varies with potential, from low to high oxidation states as follows (equation [1]). Even though a lot of work have been focused to investigate the formation of Ti oxides, considering different oxidation states and intermediaries (2)(3)(4)(5)(6)(7)(8)(9)(12)(13), scarce studies have been done in order to investigate the influence of the different types of oxide formed either over the growth of Ti passive film, or over semiconductor properties of film. In this work, the electrochemical behavior of Ti oxides is studied; the investigation considers structural changes caused by the formation of different Ti oxides during the anodic film formation in 0.1 M NaOH.…”

Response of Ti–Ni alloys for dental biomaterials to conditions in the mouth

“…From formation rate values, the following arrangement of passivation was obtained: (from the highest rate to the lowest rate) NaOH > Na 2 SO 4 > HClO 4 > NHO 3 > HCl > H 3 PO 4 > H 2 SO 4 . 154 Metikoš-Huković et al 155 employed structurally sensitive in situ methods, such as photopolarization and impedance, to examine the passivation process and the properties of the protective oxide layers on Ti. The thickness of anodic oxidation and the non-stoichiometry of the surface oxide were correlated.…”

“…The semiconducting properties of TiO 2 were investigated using an anodic film stabilized at + 2V (vs. SCE with 0.2444 V vs. NHE), and it was found that TiO 2 , like the lower titanium oxides, is an n-type (metal-excess) semiconductor under anodic polarization. 155 Re-passivation capability 156 associated with Ti substrate can be considered as another reason for the high corrosion resistance and biocompatibility of Ti materials.…”