Magnetoresistance of a single domain wall in Co and Ni nanowires

We report on the domain wall magnetoresistance of Co and Ni nanowires of 35 nm on diameter or less. The enhancement of the resistance due to an isolated domain wall is clearly evidenced from magnetoresistance hysteresis loops obtained under parallel and perpendicular fields. The domain walls magnetoresistance effect is by one order of magnitude smaller in Ni than in Co and it was observed only at low temperature for Ni nanowires. The formation and motion of domain walls is demonstrated by MFM experiments.