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E. Kozeschnik, A. Redermeier, D. Reith, T. Kerschner, R. Podloucky:
"Monte Carlo study of Cu precipitation in Fe - From temperature-dependent cluster expansion to local chemical environment potentials";
Talk: ICAMS Advanced Discussions, Bochum (invited); 2015-06-15 - 2015-06-16.

Phase decomposition in binary Fe1-xCux is studied using Monte Carlo simulations. We utilize first-principles calculations to determine reference energies of various Fe-Cu compounds that serve as input for a temperature and composition-dependent cluster expansion. The vibrational part of the temperature dependence is accounted for with phonon calculations up to 1200K. On this basis, the thermodynamic properties of the bcc Fe-Cu system are predicted and used to simulate the equilibrium constitution of bcc Cu-rich precipitates in an Fe-rich solid solution at various temperatures and supersaturations. Alternatively, we apply computationally efficient pair potentials in the local chemical environment approach that are calibrated on the first-principles cluster expansion results and that are utilized in large-scale simulations for analysis of the multi-particle precipitate evolution. On comparison of the results, we observe that both approaches provide comparable information in terms of the mean precipitate radius, composition as well as interface constitution. Whereas the cluster expansion ("full-information") path gives deep insight on the physical basis of the wide miscibility range of Cu in bcc Fe, the LCE ("fast-computation") path appears particularly useful in evaluation of cluster formation and evolution statistics.