Abstract
Synthetic antiferromagnetic (SAF) multilayer structures hold significant promise for next-generation spintronic memory devices due to their vanishing stray fields, enhanced thermal stability, and potential for high-speed current-induced domain wall (DW) motion. This study investigates the magneto-optical Kerr effect (MOKE) and current-induced DW dynamics in Pt/Co/Ru/Co/Pt multilayers, meticulously fabricated using DC magnetron sputtering. We demonstrate robust perpendicular magnetic anisotropy (PMA) and controlled antiferromagnetic coupling between the Co layers, mediated by the Ru spacer, as confirmed by MOKE magnetometry and magnetic force microscopy. Time-resolved MOKE microscopy reveals efficient current-induced DW propagation, with velocities reaching several tens of meters per second at current densities compatible with device integration. The observed DW motion is attributed to the interplay of spin-orbit torques (SOTs) originating from the heavy metal Pt layers and the Dzyaloshinskii-Moriya interaction (DMI) at the Pt/Co interfaces, which stabilizes chiral Néel walls. These findings underscore the potential of Pt/Co/Ru/Co/Pt SAFs as a platform for developing high-performance, low-power spintronic memory and logic applications, paving the way for further optimization of material parameters and device architectures.
