Isothermal anisotropic magnetoresistance in antiferromagnetic metallic IrMn

TL;DR

This study investigates the limits of anisotropic magnetoresistance in antiferromagnetic IrMn, revealing a significant 0.15% effect influenced by cooling conditions, advancing understanding in antiferromagnetic spintronics.

Contribution

The paper demonstrates a large anisotropic magnetoresistance in IrMn and shows its dependence on cooling conditions, highlighting new potential for antiferromagnetic spintronic devices.

Findings

Anisotropic magnetoresistance up to 0.15% in IrMn.

Magnetoresistance strongly affected by cooling conditions.

Transport properties modulated exclusively in the antiferromagnetic layer.

Abstract

Antiferromagnetic spintronics is an emerging field; antiferromagnets can improve the functionalities of ferromagnets with higher response times, and having the information shielded against external magnetic field. Moreover, a large list of aniferromagnetic semiconductors and metals with N\'eel temperatures above room temperature exists. In the present manuscript, we persevere in the quest for the limits of how large can anisotropic magnetoresistance be in antiferromagnetic materials with very large spin-orbit coupling. We selected IrMn as a prime example of first-class moment (Mn) and spin-orbit (Ir) combination. Isothermal magnetotransport measurements in an antiferromagnetic-metal(IrMn)/ferromagnetic-insulator thin film bilayer have been performed. The metal/insulator structure with magnetic coupling between both layers allows the measurement of the modulation of the transport properties exclusively in the antiferromagnetic layer. Anisotropic magnetoresistance as large as 0.15 % has been found, which is much larger than that for a bare IrMn layer. Interestingly, it has been observed that anisotropic magnetoresistance is strongly influenced by the field cooling conditions, signaling the dependence of the found response on the formation of domains at the magnetic ordering temperature.