Interfacial Dzyaloshinskii-Moriya Interaction: Effect of 5&ITd&IT Band Filling and Correlation with Spin Mixing Conductance

The Dzyaloshinskii-Moriya interaction (DMI) at the heavy metal (HM) and ferromagnetic metal 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/FM (FM = CoFeB, Co)/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 correlation is observed between DMI and effective spin mixing conductance at the HM/FM interfaces. Our results provide new insights into the interfacial DMI for designing future spintronic devices.