Work

Work-function control of the interfacial Dzyaloshinskii–Moriya interaction in Pt and Pd-based multilayers

Year: 2026

Type: article

Abstract: The emergence of chiral magnetic interactions at interfaces has strongly impacted our understanding of spin textures and magnetic order in low-dimensional systems. Originating from the interplay between spin–orbit coupling (SOC) and broken inversion symmetry, these interactions underpin the formation of skyrmions, chiral domain walls (DW), and other topologically non-trivial spin structures. In this article, we explore the fundamental mechanisms driving interfacial Dzyaloshinskii–Moriya interaction (DMI) through the investigation of its evolution in (Pt|Co|M)n and (Pd|Co|M)n multilayers with n=3–6 and various capping metals M (Ni, Ru, Pd, Al, Pt, and Au). The interfacial DMI constant Ds is extracted using an analytical model based on the equilibrium stripe-domain periodicity, the DW width parameter, and the internal DW angle. We find that Ds becomes almost constant, independent of n, indicating that the DMI amplitude is weakly affected by the number of repetitions (dipolar fields, quality of interfaces) in this regime. Most importantly, both the magnitude and sign of Ds exhibit a robust linear dependence on the work-function difference between Co and the capping metal, ΔΦ=ΦM−ΦCo, reflecting the interfacial potential gradient. The same slope is found for both Pt- and Pd-based multilayers despite their different SOC strengths, providing a simple and predictive route to engineer chiral interactions in metallic multilayer stacks.

Source: Applied Physics Letters

DOI: 10.1063/5.0343057