Investigation of Possible Phase Separation in Rapidly Quenched Fe$_{1-x}$Co$_x$ Alloys with Cluster Expansion Model

ORAL

Abstract

Recently, experiments observed phase separation in rapidly quenched Fe$_{1-x}$Co$_x$ alloy in the ordered $\alpha'$ phase [ J. Alloys Compd. 424, 145 (2006) ]. It is also believed that this is not an equilibrium result because of phase rule violation in the published phase diagram. To clarify this situation, we calculate the phase diagram of the system using cluster expansion in combination with a genetic algorithm. We calculated free energy of the system using super-cells up to 32 atoms with compositions ranging from 35 to 100 at. \% Fe. Possible explanations for the experimental observations will be discussed.

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Authors

  • Xin Zhao

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • Manh Cuong Nguyen

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • Min Ji

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • Iver E. Anderson

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • M.J. Kramer

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • R. William McCallum

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • Cai-Zhuang Wang

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University

  • Kai-Ming Ho

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University