Non-collinear texture formation in synthetic antiferromagnets with perpendicular magnetic anisotropy

Magnetic textures in geometrically well-confined structures have been suggested for information processing (e.g., as spin wave nanochannels) as well as storage applications. While most studies are focused on ferromagnetic (FM) systems, magnetic textures in antiferromagnetic (AF) structures have some advantages, as in the latter external dipolar fields are minimized. As a consequence, AF systems allow for high domain wall velocities and excitation frequencies up to the THz range. We present a highly stable magnetic texture in form of a pinned 180° AF domain wall, which is stabilized normal to the growth direction at the center of a multilayer stack of a synthetic antiferromagnet (SAF) with perpendicular magnetic anisotropy (PMA). The SAF is experimentally realized as a [(Co/Pt)_(X-1)/Co/Ir]_N multilayer with very strong AF interlayer exchange coupling between adjacent (Co/Pt)_(X-1)/Co blocks. It exploits the collective response of layered AF systems with an even number N of AF coupled blocks to an externally applied magnetic field, also known as the surface spin flop (SSF) state. We demonstrate how the pinned 180° AFdomain wall can be stabilized even at remanence on arbitrary (but reasonably smooth) substrates that do not rely on single crystals, which makes this type of AF texture attractive for integration into more complex magnetic systems and applications for information processing.