Origin of Magnetism and trend in $T_{c}$ in Cr-based double perovskites: Interplay of two driving mechanisms

TL;DR

This study uses first principles calculations to understand the origin of magnetism and the trend in critical temperature in Cr-based double perovskites, revealing the interplay of hybridization and super-exchange mechanisms.

Contribution

It introduces a combined first principles and model Hamiltonian approach to explain the magnetic properties and $T_c$ trend in Cr-based double perovskites.

Findings

The $T_c$ trend is explained by the interplay of hybridization and super-exchange mechanisms.

First principles calculations successfully reproduce the magnetic behavior.

The study clarifies the origin of magnetism in Sr$_2$CrB$'$O$_6$ series.

Abstract

Employing first principles density functional calculations, together with solution of the low-energy, model Hamiltonian constructed in a first principles manner, we explored the origin of magnetism and $T_c$ trend in Cr-based double perovskite series, Sr$_2$CrB$'$O$_6$ (B$'$=W/Re/Os). Our study shows that the apparently puzzling $T_c$ trend in Sr$_2$CrB$'$O$_6$ (B$'$=W/Re/Os) series can be understood in terms of the interplay of the hybridization driven mechanism and the super-exchange mechanism.