Velocity of vortex walls moved by current

Current-induced domain-wall motion experiments in 27 nm thick and 200-500 nm wide Fe20 Ni80 wires are reported. By imaging the domain-wall position after current injections, the mean wall velocities are determined. The initial velocity is found to be constant for pulse lengths between 2 and 25 μs but decays after about ten injections. For samples with an increasing wire width the initial velocity is reduced. © 2006 American Institute of Physics.