Field-Free Spin-Orbit Torque Induced Magnetization Switching in Synthetic Antiferromagnet with Perpendicular Magnetic Anisotropy

Abstract

With the advantage of exhibiting high thermal stability and zero net magnetization properties, synthetic antiferromagnets (SAFs) with perpendicular magnetic anisotropy (PMA) have attracted great interest in the field of spintronics due to their excellent properties. In this work, we investigated spin-orbit torque (SOT)-induced magnetization switching in SAF multilayer samples with Pt/Co/Ta/CoTb/Ta core structure. The perpendicular magnetic anisotropy Co layer and the ferrimagnetic CoTb layer are antiferromagnetically coupled. We realize the deterministic field-free SOT switching of the perpendicular magnetization. The elucidation of the relationship between the abnormal Hall resistance and the programming of successive current pulses demonstrates the functionality of multi-resistance states, indicating the potential application of these devices in the multi-memory spintronic memory devices.

Keywords: Synthetic antiferromagnet, perpendicular magnetic anisotropy, Spin-orbit torque, Field-free switching