Structural γ-ε phase transition in Fe-Mn alloys from a CPA  +  DMFT approach.
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 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 good agreement with experiment. We demonstrate that in contrast to the α-γ transition in pure iron, the γ-ε 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 transition temperature with Mn content.
Miheev Institute of Metal Physics, Russian Academy of Sciences, 620137 Yekaterinburg, Russia. Ural Federal University, 620002 Yekaterinburg, Russia.
A S
AS
Belozerov
A I
AI
Poteryaev
S L
SL
Skornyakov
V I
VI
Anisimov