# Integration of antiferromagnetic Heusler compound Ru$_2$MnGe into spintronic devices

## TL;DR

This paper demonstrates the first integration of an antiferromagnetic Heusler compound, Ru$_2$MnGe, as a pinning layer in magnetic tunneling junctions, achieving high magnetoresistance and high-quality interfaces.

## Contribution

It introduces the use of Ru$_2$MnGe as an antiferromagnetic pinning layer in MTJs, showing successful integration and comparable performance to existing systems.

## Key findings

- Achieved high-quality crystal growth with low interface roughness
- Demonstrated a maximum magnetoresistance of 135% in the MTJs
- Validated the potential of Ru$_2$MnGe for spintronic applications

## Abstract

We report on the first integration of an antiferromagnetic Heusler compound acting as a pinning layer into magnetic tunneling junctions. The antiferromagnet Ru$_2$MnGe is used to pin the magnetization direction of a ferromagnetic Fe layer in MgO based thin film tunnelling magnetoresistance stacks. The samples were prepared using magnetron co-sputtering. We investigate the structural properties by X-ray diffraction and reflection, as well as atomic force and high-resolution transmission electron microscopy. We find an excellent crystal growth quality with low interface roughnesses of 1-3 \r{A}, which is crucial for the preparation of working tunnelling barriers. Using Fe as a ferromagnetic electrode material we prepared magnetic tunneling junctions and measured the magnetoresistance. We find a sizeable maximum magnetoresistance value of 135%, which is comparable to other common Fe based MTJ systems.