Orbital ordering and magnetic structures in $\LMFO$ and $\LWFO$ double perovskites

TL;DR

This paper investigates the magnetic and orbital orderings in double perovskites using an extended double exchange model, revealing a complex phase diagram with various magnetic and electronic states influenced by orbital ordering.

Contribution

It introduces a simple extension of the double exchange model to analyze magnetic and orbital phases in double perovskites, highlighting the role of on-site repulsion and resulting phase diversity.

Findings

Orbital ordering is favored by on-site repulsion at Fe ions.

The phase diagram includes ferri- and antiferromagnetic phases.

Electronic states can be metallic or insulating depending on orbital order.

Abstract

We analyzed the possible magnetic and orbital orderings of double perovskites, using a simple extension of the double exchange model well suited for these compounds. Orbital ordering is favored by the on site repulsion at the Fe ions. We obtain a rich phase diagram, including ferri- and antiferromagnetic phases, which can, in turn, be metallic or insulating, depending on the existence of orbital order.