Scaling of Dzyaloshinskii Moriya interaction at heavy metal and ferromagnetic metal interfaces

TL;DR

This study investigates how the Dzyaloshinskii Moriya Interaction (DMI) varies with different heavy metal elements at HM/FM interfaces, revealing a strong dependence on 5d band filling and orbital hybridization, crucial for spintronic device design.

Contribution

It provides a comprehensive chemical trend of DMI at HM/FM interfaces and links DMI variation to 5d band filling and orbital hybridization effects.

Findings

DMI coefficient D varies up to 20 times with different 5d HM elements.

Reversal of DMI sign observed across the 5d series.

Positive correlation between DMI and spin mixing conductance.

Abstract

The Dzyaloshinskii Moriya Interaction (DMI) at the heavy metal (HM) and ferromagnetic metal (FM) interface has been recognized as a key ingredient in spintronic applications. Here we investigate the chemical trend of DMI on the 5d band filling (5d^3~5d^10) of the HM element in HM/CoFeB/MgO multilayer thin films. DMI is quantitatively evaluated by measuring asymmetric spin wave dispersion using Brillouin light scattering. Sign reversal and 20 times modification of the DMI coefficient D have been measured as the 5d HM element is varied. The chemical trend can be qualitatively understood by considering the 5d and 3d bands alignment at the HM/FM interface and the subsequent orbital hybridization around the Fermi level. Furthermore, a positive correlation is observed between DMI and spin mixing conductance at the HM/FM interfaces. Our results provide new insights into the interfacial DMI for designing future spintronic devices.