# Field-free spin-orbit torque switching in Co/Pt/Co multilayer with mixed magnetic anisotropies

## TL;DR

This study demonstrates field-free spin-orbit torque switching in a Co/Pt/Co multilayer with orthogonal magnetic anisotropies, highlighting the role of interlayer exchange coupling and potential neuromorphic applications.

## Contribution

It introduces a novel multilayer system enabling field-free SOT switching through controlled interlayer exchange coupling and tilted magnetization states.

## Key findings

- Quantified spin Hall angle of Pt as 0.08.
- Achieved field-free switching of the top Co layer.
- Potential for neuromorphic device applications.

## Abstract

Spin-orbit-torque (SOT) induced magnetization switching in Co/Pt/Co trilayer, with two Co layers exhibiting magnetization easy axes orthogonal to each other is investigated. Pt layer is used as a source of spin-polarized current as it is characterized by relatively high spin-orbit coupling. The spin Hall angle of Pt, $\theta = 0.08$ is quantitatively determined using spin-orbit torque ferromagnetic resonance technique. In addition, Pt serves as a spacer between two Co layers and depending on it's thickness, different interlayer exchange coupling (IEC) energy between ferromagnets is induced. Intermediate IEC energies, resulting in a top Co magnetization tilted from the perpendicular direction, allows for SOT-induced feld-free switching of the top Co layer. The switching process is discussed in more detail, showing the potential of the system for neuromorphic applications.