Spin-dependent scattering of a domain wall of controlled size

Abstract

Magnetoresistance measurements in the CPP geometry have been performed on single electrodeposited Co nanowires exchange biased on one side by a sputtered amorphous ${\mathrm{GdCo}}_{1.6}$ 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 ${\mathrm{GdCo}}_{1.6}$ 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.