Disentangling factors governing Dzyaloshinskii domain wall creep in Co/Ni thin films using Pt(x)Ir(1-x) seedlayers
Derek Lau, J.P. Pellegren, Hans T. Nembach, Justin M. Shaw, Vincent Sokalski
We characterize asymmetric growth of magnetic bubble domains in perpendicularly magnetized Co/Ni multi-layers grown on PtxIr1-x seedlayers by application of perpendicular and in-plane magnetic Fields. Using a refined model of domain wall creep that incorporates contributions from the anisotropic elastic energy, ", and a chirality-dependent prefactor, v0, we elucidate factors that govern the mobility of Dzyaloshinskii domain walls as a function of seedlayer composition. The interfacial Dzyaloshinskii-Moriya Interaction magnitude is found to decrease monotonically with xIr, which is independently confirmed by Brillouin light scattering (BLS). Moreover, the persistence of significant asymmetry in velocity curves across the full composition range supports previous assertions that a chirality-dependent attempt frequency akin to chiral damping could play a critical role in the observed trends. This work helps resolve fundamental questions about the factors governing Dzyaloshinskii DW creep and demonstrates varying Pt-Ir seedlayer composition as a method to tune DMI.