The magnetization reversal of each individual layer in magnetic trilayers ($\mathrm{permalloy}/\mathrm{Nd}\mathrm{Co}/\mathrm{Gd}\mathrm{Co}$) is investigated in detail with x-ray microscopy and micromagnetic calculations. Two sequential inversion mechanisms are identified. First, magnetic vortex-antivortex pairs move along the field direction while inverting the magnetization of magnetic stripes until they are pinned by defects. The vortex-antivortex displacements are reversible within a field interval which allows their controlled motion. Second, as the reversed magnetic field increases, cycloidal domains appear in the permalloy layer as a consequence of the dissociation of vortex-antivortex pairs due to pinning. The field range where magnetic vortices and antivortices are effectively guided by the stripe pattern is of the order of tens of mT for the $\mathrm{Ni}\mathrm{Fe}$ layer, as estimated from the stability of cycloid domains in the sample.

• Received 6 February 2018
• Revised 18 April 2018

DOI:https://doi.org/10.1103/PhysRevApplied.10.014008