Field-free perpendicular magnetization switching through domain wall motion in Pt/Co/Cr racetracks by spin orbit torques with the assistance of accompanying Joule heating effect

TL;DR

This study demonstrates reversible, field-free perpendicular magnetization switching in Pt/Co/Cr racetracks driven by spin orbit torques and Joule heating, advancing energy-efficient magnetic memory technologies.

Contribution

It introduces a novel Pt/Co/Cr structure enabling deterministic, field-free magnetization switching via domain wall motion enhanced by Joule heating.

Findings

Reversible switching achieved at room temperature.

Joule heating reduces the propagation field for domain walls.

Enhanced SOTs from Pt/Cr layers enable deterministic control.

Abstract

Heavy metal/ferromagnetic layers with perpendicular magnetic anisotropy (PMA) have potential applications for high-density information storage in racetrack memories and nonvolatile magnetic random access memories. Writing and erasing of information in these devices are carried out by domain wall (DW) motion and deterministic magnetization switching via electric current generated spin orbital torques (SOTs) with an assistance of in-plane bias field to break the symmetry. Improvements in energy efficiency could be obtained when the switching of perpendicular magnetization is controlled by an electric current generated SOTs without the in-plane bias fields. Here, we report on reversible electric-current-driven magnetization switching through DW motion in Pt/Co/Cr trilayers with PMA at room temperature due to the formation of homochiral Neel-type domain, in which an in-plane effective Dzyaloshinskii-Moriya interaction field exists. Fully deterministic magnetic magnetization switching in this trilayers is based on the enhancement of SOTs from a dedicated design of Pt/Co/Cr structures with two heavy metals Pt and Cr which show the opposite sign of spin Hall angles. We also demonstrated that the simultaneously accompanying Joule heating effect also plays a key role for field-free magnetization switching through the decrease of the propagation field.