Reversal behavior and stability of spin textures with different topologies in ultrathin films

Topological spin textures with an exceptional stability due to the topological protection have great potential for spintronics applications. Understanding the reversal mechanisms and stability is important for designing practical devices. Here, we prepared a system, MgO/Mn2CoAl/Pd ultrathin films, in which trivial uniform magnetic domains and nontrivial labyrinth domains and magnetic skyrmions can be generated. The reversal behaviors for those spin textures were investigated by magnetic domain imaging and magneto-Transport measurements under the influence of a magnetic field. With an external magnetic field, the trivial uniform domains can be reversed, while the nontrivial labyrinth domains and magnetic skyrmions are persistent. We also investigated the stability after switching off the field. The uniform domains stop their reversal, and the topologically nontrivial spin textures transform to a demagnetized state. These reversal behaviors and stability of the domains can be explained by referring to changes in the competition of interactions with applied magnetic field. Our results demonstrate that a large enough perpendicular magnetic anisotropy is required to stabilize topological spin textures for practical spintronics applications.