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TitleEstimates of thermodynamic stability of iron-chromium spinels in aqueous solution based on first-principles calculations
Publication TypeJournal Article
Year of Publication2007
AuthorsIngham, B., Hendy S.C., Laycock N.J., and Ryan M.P.
JournalElectrochemical and Solid-State Letters
PaginationC57 - C59
Date Published2007
ISSN10990062 (ISSN)
KeywordsChromium, Density functional theory, Iron compounds, Magnetite, Passivity, Pourbaix diagrams, Thermodynamic stability
AbstractWe report on first-principles calculations of the thermodynamic stability of the passive film on FeCr alloys. Using density functional theory we calculate the total energy of a sequence of spinels Fe3-2x Cr2x 04 (0.0x1.0) relative to magnetite (x=0.0). We use the calculated energy of formation to deduce Pourbaix diagrams for the alloy/oxide system as a function of oxide Cr content and show that these are consistent with experiments if one takes into account the observed Cr enrichment of these films. Indeed, these calculations show that the observed enrichment is a necessary requirement for passivity. © 2007 The Electrochemical Society.

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