Damping in Ru/Co-based multilayer films with large Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates Ru/Co multilayer films, demonstrating they possess significant interfacial Dzyaloshinskii-Moriya interaction with low damping, making them promising for spintronic applications, and shows how lattice strain can control DMI strength.

Contribution

It introduces Ru/Co bi-layers as a new low-damping, high-DMI material candidate and explores strain effects on DMI, expanding material options for spintronics.

Findings

Ru/Co bi-layers exhibit high interfacial DMI with low damping.

Lattice strain can significantly modulate DMI strength.

Compared systematically with Pt/Co bi-layers for potential applications.

Abstract

Recent development of the magnetic material engineering led to achievement of the systems with a high interfacial Dzyaloshinskii-Moriya interaction (DMI). As a result, the formation of non-collinear magnetic soliton states or nonreciprocal spin wave dynamics is achievable. Typically used materials are based on bi-layers Heavy Metal/Ferromagnet, e.g., Pt/Co. These layers are characterized not only by a strong DMI, but also by the spin pumping effect and the resulting relatively large damping. Here, we show that the considerable interfacial DMI can be also present in bi-layers based on Ru/Co, characterized with low spin pumping effect and low damping. It is therefore a good candidate for the dynamical studies and implementations of chiral DMI. It is demonstrated by theoretical calculations that the value of DMI can be strongly affected and controlled by the strain of the lattice. We show a systematic experimental and theoretical comparison of magnetic material parameters between Pt/Co and Ru/Co bi-layers as a deserving candidate for spintronic and spin-orbitronic applications.