Unraveling the influence of electronic and magnonic spin current injection near the magnetic ordering transition of IrMn metallic antiferromagnets

TL;DR

This study demonstrates that spin injection efficiency near the magnetic transition temperature in IrMn antiferromagnets is enhanced for both electronic and magnonic transport, independent of exchange coupling, with magnons penetrating deeper than electrons.

Contribution

It reveals that spin injection amplification near the transition temperature is independent of the transport regime and exchange coupling, and confirms deeper magnonic penetration in IrMn.

Findings

Enhanced spin injection efficiency near the transition temperature for both transport regimes.

Spin current carried by magnons penetrates deeper than conduction electrons.

The transition temperature is unaffected by the nature of the spin current or exchange coupling.

Abstract

Although spin injection at room temperature in an IrMn metallic antiferromagnet strongly depends on the transport regime, and is more efficient in the case of magnonic transport, in this article, we present experimental data demonstrating that the enhanced efficiency of spin injection caused by spin fluctuations near the ordering temperature can be as efficient for the electronic and magnonic transport regimes. By selecting representative interacting environments, we also demonstrated that the amplification of spin injection near the ordering temperature of the IrMn antiferromagnet is independent of exchange coupling with an adjacent NiFe ferromagnet. In addition, our findings confirm that the spin current carried by magnons penetrates deeper than that transported by conduction electrons in IrMn. Finally, our data indicates that the value of the ordering temperature for the IrMn antiferromagnet is not significantly affected by either the electronic or magnonic nature of the spin current probe, or by exchange coupling.