English

Structural ${\gamma\textrm{-}\varepsilon}$ phase transition in Fe-Mn alloys from CPA+DMFT approach

Strongly Correlated Electrons 2015-10-02 v3

Abstract

We present a computational scheme for total energy calculations of disordered alloys with strong electronic correlations. It employs the coherent potential approximation combined with the dynamical mean-field theory and allows one to study the structural transformations. The material-specific Hamiltonians in the Wannier function basis are obtained by density functional theory. The proposed computational scheme is applied to study the γ-ε{\gamma\textrm{-}\varepsilon} structural transition in paramagnetic Fe-Mn alloys for Mn content from 10 to 20 at. %. The electronic correlations are found to play a crucial role in this transition. The calculated transition temperature decreases with increasing Mn content and is in a good agreement with experiment. We demonstrate that in contrast to the α-γ{\alpha\textrm{-}\gamma} transition in pure iron, the γ-ε{\gamma\textrm{-}\varepsilon} transition in Fe-Mn alloys is driven by a combination of kinetic and Coulomb energies. The latter is found to be responsible for the decrease of the γ-ε{\gamma\textrm{-}\varepsilon} transition temperature with Mn content.

Keywords

Cite

@article{arxiv.1411.5356,
  title  = {Structural ${\gamma\textrm{-}\varepsilon}$ phase transition in Fe-Mn alloys from CPA+DMFT approach},
  author = {A. S. Belozerov and A. I. Poteryaev and S. L. Skornyakov and V. I. Anisimov},
  journal= {arXiv preprint arXiv:1411.5356},
  year   = {2015}
}

Comments

9 pages, 7 figures