Giant interfacial induced Dzyaloshinskii-Moriya interaction in polycrystalline Co/Pt multilayers

Abstract

Multilayers of heavy metals and ferromagnets are the basis for the formation of various structures with inhomogeneous chiral magnetic distributions. The most informative method for studying magnetic states in such structures with a high spatial resolution is Lorentz transmission electron microscopy (L-TEM). Here, we report on the observation of chiral N\'eel domain walls by means of L-TEM in Co/Pt multilayers with perpendicular magnetic anisotropy. We explain the existence of chiral N\'eel internal structure due to the overcritical, giant interfacial induced Dzyaloshinskii-Moriya interaction. Our results are confirmed by micromagnetic modeling, which allows taking into account the effect of local inhomogeneity of the magnetic anisotropy of polycrystalline films on formation of spin textures.