The Surface Spin Flop in Fully Tunable Synthetic Antiferromagnets with Perpendicular Magnetic Anisotropy

We present experimental and micromagnetic studies of the magnetization reversal in [(Co/Pt)$_{X-1}$/Co/Ir]$_{N-1}$(Co/Pt)$_X$ synthetic antiferromagnets (SAFs), where interface induced perpendicular magnetic anisotropy (PMA) and antiferromagnetic (AF) interlayer exchange coupling (IEC) are completely controlled via the individual layer thicknesses. By combining strong PMA with even stronger AF IEC we succeeded to stabilize the characteristic surface spin flop state for even N SAFs. Our system provides a well-controlled vertical AF domain wall, easy to integrate as no single crystal substrates are required and with uniform 2D-magnetization in the film plane for further functionalization options.