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

摘要

The Dzyaloshinskii Moriya Interaction (DMI) at the heavy metal (HM) andferromagnetic metal (FM) interface has been recognized as a key ingredient inspintronic applications. Here we investigate the chemical trend of DMI on the5d band filling (5d^3~5d^10) of the HM element in HM/CoFeB/MgO multilayer thinfilms. DMI is quantitatively evaluated by measuring asymmetric spin wavedispersion using Brillouin light scattering. Sign reversal and 20 timesmodification of the DMI coefficient D have been measured as the 5d HM elementis varied. The chemical trend can be qualitatively understood by consideringthe 5d and 3d bands alignment at the HM/FM interface and the subsequent orbitalhybridization around the Fermi level. Furthermore, a positive correlation isobserved between DMI and spin mixing conductance at the HM/FM interfaces. Ourresults provide new insights into the interfacial DMI for designing futurespintronic devices.