Fragility of ferromagnetic double exchange interactions and pressure tuning of magnetism in 3d-5d double perovskite Sr2FeOsO6

TL;DR

This study explores how applying pressure to Sr2FeOsO6, a 3d-5d double perovskite, induces a continuous change in magnetic exchange interactions, leading to a transition from antiferromagnetic to ferrimagnetic order, revealing new tunability in such materials.

Contribution

The paper demonstrates pressure-induced tuning of magnetic interactions in 3d-5d double perovskites, highlighting the role of 5d wave functions in magnetic property control.

Findings

Pressure causes a sign change in Fe-Os exchange interactions.

Transition from antiferromagnetic to ferrimagnetic order under pressure.

Analysis of electron-electron interactions explains the magnetic behavior.

Abstract

The ability to tune exchange (magnetic) interactions between 3d transition metals in perovskite structures has proven to be a powerful route to discovery of novel properties. Here we demonstrate that the introduction of 3d-5d exchange pathways in double perovskites enables additional tunability, a result of the large spatial extent of 5d wave functions. Using x-ray probes of magnetism and structure at high pressure, we show that compression of Sr2FeOsO6 drives an unexpected continuous change in the sign of Fe-Os exchange interactions and a transition from antiferromagnetic to ferrimagnetic order. We analyze the relevant electron-electron interactions, shedding light into fundamental differences with the more thoroughly studied 3d-3d systems.