Electron correlations in Co$_2$Mn$_{1-x}$Fe$_x$Si Heusler compounds

TL;DR

This paper investigates how local electronic correlations influence the properties of Co$_2$Mn$_{1-x}$Fe$_x$Si Heusler compounds using first-principles calculations, highlighting the importance of both static and dynamic correlations for accurate descriptions.

Contribution

It introduces a comprehensive analysis of static and dynamic electronic correlations in Co$_2$Mn$_{1-x}$Fe$_x$Si using LSDA+U and DMFT methods within the KKR framework, aligning theory with experimental data.

Findings

Correlation effects are crucial for explaining magnetic and spectroscopic properties.

Both static and dynamic correlations must be considered for accurate electronic structure.

The study achieves good agreement with experimental observations.

Abstract

This study presents the effect of local electronic correlations on the Heusler compounds Co$_2$Mn$_{1-x}$Fe$_x$Si as a function of the concentration $x$. The analysis has been performed by means of first-principles band-structure calculations based on the local approximation to spin-density functional theory (LSDA). Correlation effects are treated in terms of the Dynamical Mean-Field Theory (DMFT) and the LSDA+U approach. The formalism is implemented within the Korringa-Kohn-Rostoker (KKR) Green's function method. In good agreement with the available experimental data the magnetic and spectroscopic properties of the compound are explained in terms of strong electronic correlations. In addition the correlation effects have been analysed separately with respect to their static or dynamical origin. To achieve a quantitative description of the electronic structure of Co$_2$Mn$_{1-x}$Fe$_x$Si both static and dynamic correlations must be treated on equal footing.