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Atomic-scale study of low-temperature equilibria in iron-rich Al-C-Fe

Besson, Rémy and Legris, Alexandre and Connétable, Damien and Maugis, Philippe Atomic-scale study of low-temperature equilibria in iron-rich Al-C-Fe. (2008) Physical Review B: Condensed Matter, 78 (1). 014204/1-014204/11. ISSN 1098-0121

(Document in English)

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Official URL: http://dx.doi.org/10.1103/PhysRevB.78.014204


The capability of the thermodynamic approach based on the independent point defect approximation to describe low-temperature phase equilibria is investigated and applied to the Al-C-Fe system. The method gives a reasonable description of the multicomponent and multisublattice Fe-rich corner and evidences numerous peculiarities concerning the ordered phases as well as the density-functional-theory (DFT) energy models. The study of Fe3Al(-C), revealing strong defect-induced instabilities, rules out the LDA, SLDA and GGA schemes and leaves (spin-polarized) SGGA as the only valid one. C stabilizes L12 Fe3Al with respect to D03, which justifies the fcc-type structure of the kappa Fe3AlC compound. The present work also helps in justifying the experimentally observed depletion of C in the kappa phase. Finally, a correct description of both Fe3C and kappa requires inclusion of interstitial carbon at low temperature, emphasizing the unexpected importance of interstitial defects in ordered phases.

Item Type:Article
Additional Information:Thanks to American Physical Society editor. The definitive version is available at http://scitation.aip.org The original PDF of the article can be found at Physical Review B: Condensed Matter website : http://prb.aps.org/
HAL Id:hal-00806033
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Other partners > EDF (FRANCE)
Other partners > Ecole Nationale Supérieure de Chimie de Lille - ENSCL (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Université des Sciences et Technologies de Lille - USTL (FRANCE)
Laboratory name:
Deposited On:20 May 2009 14:20

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