A multimodal approach to revisiting oxidation defects in Cr2O3

Autor: R. Auguste, H. L. Chan, E. Romanovskaia, J. Qiu, R. Schoell, M. O. Liedke, M. Butterling, E. Hirschmann, A. G. Attallah, A. Wagner, F. A. Selim, D. Kaoumi, B. P. Uberuaga, P. Hosemann, J. R. Scully
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: npj Materials Degradation, Vol 6, Iss 1, Pp 1-13 (2022)
Druh dokumentu: article
ISSN: 2397-2106
94188912
DOI: 10.1038/s41529-022-00269-7
Popis: Abstract The oxidation of chromium in air at 700 °C was investigated with a focus on point defect behavior and transport during oxide layer growth. A comprehensive set of characterization techniques targeted characteristics of chromium oxide microstructure and chemical composition analysis. TEM showed that the oxide was thicker with longer oxidation times and that, for the thicker oxides, voids formed at the metal/oxide interface. PAS revealed that the longer the oxidation time, there was an overall reduction in vacancy-type defects, though chromium monovacancies were not found in either case. EIS found that the longer oxidized material was more electrochemically stable and that, while all oxides displayed p-type character, the thicker oxide had an overall lower charge carrier density. Together, the results suggest anion oxygen interstitials and chromium vacancy cluster complexes drive transport in an oxidizing environment at this temperature, providing invaluable insight into the mechanisms that regulate corrosion.
Databáze: Directory of Open Access Journals
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