Element-selective modulation of interfacial Dzyaloshinskii-Moriya interaction in Pt|Co|Metal based multilayers

TL;DR

This study investigates the origins of interfacial Dzyaloshinskii-Moriya interaction (DMI) in multilayers, revealing how different metal interfaces influence DMI through properties like work function difference, enabling precise magnetic engineering.

Contribution

It provides a detailed analysis of how various metal interfaces affect DMI, establishing a linear relationship with work function difference, which aids in targeted magnetic property tuning.

Findings

Linear correlation between DMI and work function difference.

Interfacial potential gradient influences DMI strength.

Different metals modulate DMI based on intrinsic properties.

Abstract

Despite a decade of research, the precise mechanisms occurring at interfaces underlying the Dzyaloshinskii-Moriya interaction (DMI), and thus the possibility of fine-tuning it, are not yet fully identified. In this study, we investigate the origin of the interfacial DMI, aiming at disentangling how independent are the interfaces around the ferromagnetic layer, and what are their relative contributions to the effective DMI amplitude. For this purpose, we have grown and investigated a large variety of systems with a common structure Pt$|$Co$|M$ with $M =$ Ni, Pd, Ru, Al, Al$|$Ta and MoSi. We explore the correlation between the effective interfacial DMI, and different intrinsic properties of metals, namely atomic number, electronegativity and work function difference at the Co$|M$ interfaces. We find a linear relationship between interfacial DMI and the work function difference between the two elements, hence relating the nature of this behavior to the interfacial potential gradient at the metallic interfaces. The understanding of the DMI mechanism is of utmost importance since it opens up the possibility of precisely engineering the magnetic and hence the spintronic properties for future devices.