Artigo
An ellipsometric study of manganese oxide films: In situ characterization of the deposition and electroreduction of MnO2
Fecha
2005-02-07Registro en:
Journal of the Electrochemical Society, v. 152, n. 1, 2005.
0013-4651
10.1149/1.1825951
2-s2.0-12744255073
2-s2.0-12744255073.pdf
Autor
Univ. Nac. de Santiago del Estero
Univ. Nacional de Córdoba
INIFTA
Universidade Estadual Paulista (Unesp)
Resumen
The electrodeposition of manganese oxide films onto a platinum substrate was investigated by means of in situ ellipsometry. In the thickness range from 0 to 150 nm, the anodic oxide behaves as an Isotropic single layer with optical constants that are independent of thickness. Deviations at higher thickness are explained in terms of anisotropic properties of the film. The electroreduction of thin films (up to ca. 150 nm) in an alkaline electrolyte leads to a decrease in both the refractive index and the extinction coefficient and is accompanied by a thickness increase of ca. 10%. The Mn(IV) to Mn(III) conversion takes place from the oxide/electrolyte interface inwards. © 2004 The Electrochemical Society. All rights reserved.