Spin-dependent scattering of a domain wall of controlled size

Magnetoresistance measurements in the CPP geometry have been performed on single electrodeposited Co nanowires exchange biased on one side by a sputtered amorphous GdCo1.6 layer. This geometry allows the stabilization of a single domain wall in the Co wire, the thickness of which can be controlled by an external magnetic field. Comparing magnetization, resistivity, and magnetoresistance studies of single Co nanowires, of GdCo1.6 layers, and of the coupled system, gives evidence for an additional contribution to the magnetoresistance when the domain wall is compressed. This contribution could be interpreted as the spin-dependent scattering within the domain wall when the wall thickness becomes smaller than the spin diffusion length.