Tuning the Dzyaloshinskii-Moriya Interaction in Pt/Co/MgO heterostructures through MgO thickness

TL;DR

This paper investigates how varying MgO thickness in Pt/Co/MgO heterostructures affects the Dzyaloshinskii-Moriya interaction, revealing a method to optimize skyrmion stability for spintronic devices.

Contribution

It demonstrates the tunability of DMI in heterostructures through MgO and Co thickness adjustments, providing insights for designing skyrmion-based electronics.

Findings

DMI field varies non-monotonically with MgO and Co thickness.

Maximum DMI field depends on the specific Co and MgO thicknesses.

Interface modifications influence magnetic properties significantly.

Abstract

The interfacial Dzyaloshinskii-Moriya interaction (DMI) in the ferromagnetic/heavy metal ultra-thin film structures , has attracted a lot of attention thanks to its capability to stabilize Neel-type domain walls (DWs) and magnetic skyrmions for the realization of non-volatile memory and logic devices. In this study, we demonstrate that magnetic properties in perpendicularly magnetized Ta/Pt/Co/MgO/Pt heterostructures, such as magnetization and DMI, can be significantly influenced through both the MgO and the Co ultrathin film thickness. By using a field-driven creep regime domain expansion technique, we find that non-monotonic tendencies of DMI field appear when changing the thickness of MgO and the MgO thickness corresponding to the largest DMI field varies as a function of the Co thicknesses. We interpret this efficient control of DMI as subtle changes of both Pt/Co and Co/MgO interfaces, which provide a method to investigate ultra-thin structures design to achieve skyrmion electronics.