Determination of the phase diagram from interatomic potentials: The iron–chromium case

Giovanni Bonny, Roberto Pasianot, Evgeny Zhurkin, Marc Hou, Lorenzo Malerba

    Research outputpeer-review


    Prior to applying any interatomic potential, it is important to know the stability of the different phases it describes. In the literature many methods to determine the phase diagram from an interatomic potential are described. Although for pure elements the procedure to obtain the thermodynamic functions is well established, for alloys it is not. In this work a method is developed to determine the phase diagram, i.e., solubility limits and spinodal gap, for the case of miscibility gaps. The method combines Monte Carlo simulations in the isobaric semi-grand canonical ensemble, full thermodynamic integration and Redlich-Kister expansions to parameterize the Gibbs free energy. Besides numerical inaccuracies, this method does not rely on any physical approximations to determine the phase diagram of a given interatomic potential. The method is applied to two different Fe–Cr potentials that are widely used in the literature. The resulting phase diagrams are discussed by comparing them to the experimental one and ones obtained in other works from the same potentials.
    Original languageEnglish
    Pages (from-to)2216-2220
    JournalComputational Materials Science
    Issue number7
    StatePublished - Apr 2011

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