Magnetoresistance and domain wall motion in horseshoe Ni80Fe20 wires

Abstract The characteristics of current-driven magnetic domain wall motion are quite different to those driven by conventional magnetic field. We have been observed this effect by means of a horseshoe permalloy wire. Two magnetic states were found in this pattern. One is the vortex type domain wall at the center of semicircular arc area of the horseshoe pattern and the other is the continuous magnetic state without domain wall in between. The gap in between wire is 4 μm and in general, the current density of the order of ∼10 7  A/cm 2 is required to induce a magnetic domain wall motion. However, it can be reduced extensively if the current is applied just below its coercive force.