Thickness determination of electrochemical titanium oxide (Ti/TiO2) formed in HClO4 solutions

FRANCISCO A FILIPPIN; OMAR E. LINAREZ PÉREZ; MANUEL LÓPEZ TEIJELO; RITA D BONETTO; JORGE TRINCAVELLI; LUCIA B. AVALLE

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2014 vol. 129 p. 266 - 266

0013-4686

nodic Titanium oxide films were potentiodinamically grown on Ti foil and glass/Ti in 0.010 M HClO4 at 50 mVs-1. The current density-potential curves (j-E) showed that the oxide grows according to the physical model for high-field conduction. However, for final potential Ef higher than 1.5 V vs. Ag/AgCl (sat. KCl) the oxygen evolution reaction becomes more significant, and the formation of bubbles prevented or made more difficult the application of in situ techniques for the simultaneous study of the thickness and optical properties of the anodic layer. We developed a method based on electron probe microanalysis (EPMA) to calculate oxide thickness using ex situ ellipsometry as a reference technique. The normalized intensity of the O K alpha peaks was measured for anodic oxides corresponding to Ef values from spontaneous oxide up to 50 V, where a linear relationship was observed for a narrower range of final potentials. After calibration with ellipsometric results to take into account