# Large spin Hall magnetoresistance in antiferromagnetic \alpha-Fe2O3/Pt heterostructures

## TL;DR

This study demonstrates a large spin Hall magnetoresistance in alpha-Fe2O3/Pt heterostructures at room temperature, with implications for antiferromagnetic spintronics due to its high SMR amplitude and low saturation field.

## Contribution

It reveals a significantly enhanced SMR in alpha-Fe2O3/Pt heterostructures, surpassing that of ferrimagnetic counterparts, and highlights their potential for room-temperature antiferromagnetic spintronic devices.

## Key findings

- Maximum SMR amplitude of 0.25% observed.
- SMR saturates at lower magnetic fields than other antiferromagnets.
- Sinusoidal resistivity oscillation confirms Neel vector rotation.

## Abstract

We investigate the spin Hall magnetoresistance (SMR) at room temperature in thin film heterostructures of antiferromagnetic, insulating, (0001)-oriented alpha-Fe2O3 (hematite) and Pt. We measure their longitudinal and transverse resistivities while rotating an applied magnetic field of up to 17T in three orthogonal planes. For out-of-plane magnetotransport measurements, we find indications for a multidomain antiferromagnetic configuration whenever the field is aligned along the film normal. For in-plane field rotations, we clearly observe a sinusoidal resistivity oscillation characteristic for the SMR due to a coherent rotation of the Neel vector. The maximum SMR amplitude of 0.25% is, surprisingly, twice as high as for prototypical ferrimagnetic Y3Fe5O12/Pt heterostructures. The SMR effect saturates at much smaller magnetic fields than in comparable antiferromagnets, making the alpha-Fe2O3/Pt system particularly interesting for room-temperature antiferromagnetic spintronic applications.