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

Anodic 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....

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Detalles Bibliográficos
Autores: Filippin, Francisco Angel, Linarez Pérez, Omar Ezequiel, Lopez Teijelo, Manuel, Bonetto, Rita Dominga, Trincavelli, Jorge Carlos, Avalle, Lucia Bernardita
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/31573
Acceso en línea:http://hdl.handle.net/11336/31573
Access Level:acceso abierto
Palabra clave:Electrochemistry
Ellipsometry
Epma
Oxide Growth
Tio2
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:Anodic 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 Kα 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. This behaviour was studied with Monte Carlo simulations. After calibration with ellipsometric results, to take into account sample damage during the electron irradiation, EPMA was applied as a method for thickness determination at Ef ≥ 1.0 V. Once the method was established, ex situ thickness determinations became independent of the preparation method of the oxide layer, which represents a comparative advantage against ex situ ellipsometry.