Exploring the suitable theoretical approach for understanding the electronic and magnetic properties of $α$-Iron

Abstract

We present a comparative electronic structure study using DFT and various beyond-DFT (DFT+U , G0W0, DFT+DMFT) methods for ferromagnetic Iron (Fe) to find better approach for describing the spectral properties of correlated magnetic system. The computed value of U (W ) is ∼5.4 (∼0.8) eV. The calculated spectra of all methods are providing good agreement with experimental spectra (ES) for peaks' positions. But, the proper line shape is only found from DFT+DMFT with correct estimation of incoherent states, which depends on J and form of local Coulomb interactions. The estimation of reduced magnetization as function of reduced temperature using DFT+DMFT shows good agreement with the experimental data. The insight of paramagnetic electronic structure of Fe is also explored. This work suggests that even for simple correlated magnetic metal, we need DFT+DMFT method to reproduce the ES with great accuracy.

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

“…The imaginary part of self-energy gives a picture of strength of interaction and lifetime of carriers. The electronic structure and strength of EEI in solids is normally studied using GW or DFT + dynamical mean field theory methods [21][22][23]. The electron-phonon matrix elements can be calculated under combined density functional perturbation theory (DFPT) and using Wannier functions for interpolation method [24].…”

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

“…The imaginary part of self-energy gives a picture of strength of interaction between carriers. The electronic structure and strength of EEI in solids is normally studied using GW or DFT + dynamical mean field theory (DMFT) methods [21][22][23]. The electron-phonon matrix elements can be calculated under combined density functional perturbation theory (DFPT) and using Wannier functions for interpolation method [24].…”