Investigation of anomalous-Hall and spin-Hall effects of antiferromagnetic IrMn sandwiched by Pt and YIG layers

TL;DR

This study explores how IrMn layers influence anomalous-Hall and spin-Hall effects in heterostructures with Pt and YIG, revealing enhanced AHR, suppressed MPE, and effective spin current transport dependent on IrMn thickness and temperature.

Contribution

It demonstrates the dual role of IrMn in enhancing AHR and blocking MPE, providing insights into spin transport mechanisms in antiferromagnetic heterostructures.

Findings

AHR is significantly enhanced at higher temperatures and peaks at 3 nm IrMn thickness.

Spin current can penetrate the IrMn layer to interact with YIG, evidenced by SMR.

IrMn insertion suppresses the magnetic proximity effect on Pt.

Abstract

We report an investigation of temperature and IrMn layered thickness dependence of anomalous-Hall resistance (AHR), anisotropic magnetoresistance (AMR), and magnetization on Pt/Ir20Mn80/Y3Fe5O12 (Pt/IrMn/YIG) heterostructures. The magnitude of AHR is dramatically enhanced compared with Pt/YIG bilayers. The enhancement is much more profound at higher temperatures and peaks at the IrMn thickness of 3 nm. The observed spin-Hall magnetoresistance (SMR) in the temperature range of 10-300 K indicates that the spin current generated in the Pt layer can penetrate the entire thickness of the IrMn layer to interact with the YIG layer. The lack of conventional anisotropic magnetoresistance (CAMR) implies that the insertion of the IrMn layer between Pt and YIG efficiently suppresses the magnetic proximity effect (MPE) on induced Pt moments by YIG. Our results suggest that the dual roles of the InMn insertion in Pt/IrMn/YIG heterostructures are to block the MPE and to transport the spin current between Pt and YIG layers. We discuss possible mechanisms for the enhanced AHR.