Domain Wall Motion in Synthetic Co2Si Nanowires

We report the synthesis of single crystalline Co2Si nanowires and the electrical transport studies of single Co2Si nanowire devices at low temperature. The butterfly shaped magnetoresistance shows interesting ferromagnetic features, including negative magnetoresistance, hysteretic switch fields, and stepwise drops in magnetoresistance. The nonsmooth stepwise magnetoresistance response is attributed to magnetic domain wall pinning and depinning motion in the. Co2Si nanowires probably at crystal or morphology defects. The temperature dependence of the domain wall depinning field is observed and described by a model based on thermally assisted domain wall depinning over a single energy barrier.