Study of passive films formed on mild steel in alkaline media by the application of anodic potentials

Abril 2009

In this paper, iron oxide thin layers formed on mild steel substrates in alkaline media by the application of different anodic potentials were studied in order to characterize their morphology, composition and electrochemical behaviour, in particular under conditions of cathodic protection. The surface composition was evaluated by X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). The morphology of the surface oxides was studied via Atomic Force Microscopy (AFM). The electrochemical behaviour of the surface oxides was studied using Electrochemical Impedance Spectroscopy (EIS). The results showed that the surface film is composed by Fe2+oxides and Fe3+ oxides and/or hydroxides. The contribution of Fe2+ species vanishes when the potential of film formation increases in the passive domain. Two distinct phases were differentiated in the outer layers of the surface film, which proves that film growing is topotactic in nature.

Autores da comunidade :

• 

  M

  Maria de Fátima Grilo da Costa Montemor

  ist23859

  Afiliações e fontes

  IST > CQE

  Centro de Química Estrutural

  IST > DEQ

  Departamento de Engenharia Química

  De: scopus

  ID: 2-s2.0-58849112973

  De: orcid

  ID: 17205650

VoR - Versão publicada

Elsevier BV

Materials Chemistry and Physics

962

972

114

2-3

0254-0584

10.1016/j.matchemphys.2008.11.012

chemical-sciences - Química

Palavras-chave

• Condensed Matter Physics
• General Materials Science

eng - Inglês