Mn and Fe Impurities in MgB_{2}

TL;DR

This study uses first principles calculations to investigate how Mn and Fe impurities affect the electronic and magnetic properties of MgB2, revealing Mn as magnetic and Fe as nearly non-magnetic impurities.

Contribution

It provides a detailed comparison of Mn and Fe impurities in MgB2, highlighting their different magnetic behaviors and effects on electronic structure.

Findings

Mn impurities are magnetic due to exchange-splitting of d orbitals.

Mn significantly modifies B p bands through hybridization.

Fe impurities are nearly non-magnetic in MgB2.

Abstract

Based on first principles calculations, we show that $Mn$ impurities are magnetic in $MgB_{2}$ due to exchange-splitting of $d_{3z^2-1}$ band and they substantially modify $B$ $p_{\sigma}$ and $p_{\pi}$ bands through hybridization. Thus, $Mn$ impurities could act as strong magnetic scattering centers leading to pair-breaking effects in $MgB_{2}$. In contrast, we find $Fe$ impurities in $MgB_{2}$ to be nearly non-magnetic.