Kinetics versus thermodynamics in materials modeling: The case of the divacancy in iron

Flyura Djurabekova, Lorenzo Malerba, Roberto C. Pasianot, Pär Olsson, Kai Nordlund, Nicolas Castin

    Research outputpeer-review


    Monte Carlo models are widely used for the study of microstructural and microchemical evolution of materials under irradiation. However, they often link explicitly the relevant activation energies to the energy difference between local equilibrium states. We provide a simple example (di-vacancy migration in iron) in which a rigorous activation energy calculation, by means of both empirical interatomic potentials and density functional theory methods, clearly shows that such a link is not granted, revealing a migration mechanism that a thermodynamics-linked activation energy model cannot predict. Such a mechanism is, however, fully consistent with thermodynamics. This example emphasizes the importance of basing Monte Carlo methods on models where the activation energies are rigorously calculated, rather than deduced from widespread heuristic equations.
    Original languageEnglish
    Pages (from-to)2585-2595
    JournalPhilosophical Magazine
    Issue number19
    StatePublished - 28 Apr 2010

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