Current-and field-driven domain wall motion in L-and C-shaped permalloy nanowires with different wire widths

We investigated the pulse-current-driven and magnetic-field-driven domain wall (DW) motion in permalloy nanowires with different shapes and wire widths. Two different nanowire types, 600 nm wide L-and 300 nm wide C-shaped, were considered by means of magnetic force microscope and anisotropic magnetoresistance measurement. We confirmed that every time head-to-head vortex DWs were placed at the specific places as we intended for both types of nanowires. We found similar critical current densities (̃5 X 10 ¹¹ A/m ²) and DW velocity (̃2.0 m/s) for both nanowires in spite of their different shapes and widths. Multiple vortex DWs were also observed when the applied current density exceeded only a few percent of the critical values. We also performed magnetic-field-driven DW propagations. From the pinning and depinning images and anisotropic magnetoresistance measurement, we found the magnetoresistance value of the single vortex type DW for the L-shaped permalloy nanowire.