Boosting domain wall velocity and stability in ferrimagnetic GdFe nanowires by applying laser-annealing process

Abstract

This study highlights the significant achievement of enhancing domain wall (DW) velocity through the laser-annealing (LA) process in GdxFe100−x films, with a specific focus on the Gd26Fe74 composition. By investigating the current-induced DW motion, it was observed that the LA process on the edges and middle of the nanowires resulted in a remarkable improvement in DW velocity from around 600 m/s for non-laser-annealed to 1800 m/s for laser-annealed conditions. Furthermore, we conducted additional experiments to explore the stability and dynamics of a system involving DWs in a single wire. The experimental results revealed a stable and uniform movement of the DWs, as evidenced by a velocity of approximately 1800 m/s, even after the application of 20 pulses with a short pulse width of 1 ns. The resulting stability of the DW motion across a wide range of applied currents demonstrates the practical significance of the LA in achieving high-performance racetrack memories. Our findings suggest that the LA process has a similar effect on both the middle and edge treatments of the wire. This indicates that structural defects on the wire's edges are not the main cause of the observed low velocity or curvy shape of DWs. One possible mechanism for this effect is the reduction of the Ku value through the LA process. This study establishes a ground-breaking advancement by showcasing the effectiveness of the LA in enhancing DW motion velocity in GdFe ferrimagnetic thin films, thereby opening avenues for future research and industrial applications in this field.