Publication Type Journal Article
Title The influence of copper and chromium on the semiconducting behaviour of passive films formed on weathering steels
Authors I. C. Guedes I. V. Aoki Maria J. Carmezim Maria F. Montemor M. G. S. Ferreira M. Da Cunha Belo
Groups
Journal THIN SOLID FILMS
Year 2006
Month December
Volume 515
Number 4
Pages 2167-2172
Abstract The influence of small amounts of alloying elements (0.36\% Cu and 0.47\% Cr) on the semiconducting properties of passive films formed on weathering steels was investigated either in tetraborate/boric acid buffer solution (pH 9.2) or artificial atmospheric environment (SO2-containing environment). The electrochemical behaviour was assessed by potentiodynamic polarisation, capacitance measurements and photoelectrochemistry. The chemical characterisation of the films was carried by Auger electron spectroscopy. The polarization results obtained in the buffer solution show that the addition of chromium decreases the passive current density. The capacitance results show that the films behave as an n-type semiconductor with shallow and deep donor levels situated in the forbidden gap. The presence of copper seems to affect the density of the shallow and of the deep donor levels in the forbidden gap, and as chromium, it also decreases the doping density in the case of the films formed in the SO2-containing environment. The addition of copper and chromium on carbon steel did not influence the band gap energy of the passive films. (c) 2006 Elsevier B.V. All rights reserved.
DOI http://dx.doi.org/10.1016/j.tsf.2006.05.011
ISBN
Publisher
Book Title
ISSN 0040-6090
EISSN
Conference Name
Bibtex ID ISI:000242931900149
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