Spin-dependent scattering of a domain wall of controlled size

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