Magnetoresistance, micromagnetism, and domain-wall scattering in epitaxial hcp Co films

Large negative magnetoresistance ~MR! observed in transport measurements of hcp Co films with stripe domains were recently reported and interpreted in terms of domain-wall ~DW! scattering mechanism. Here detailed MR measurements, magnetic force microscopy, and micromagnetic calculations are combined to elucidate the origin of MR in this material. The large negative room-temperature MR reported previously is shown to be due to ferromagnetic resistivity anisotropy. Measurements of the resistivity for currents parallel ~CIW! and perpendicular to DW’s ~CPW! have been conducted as a function of temperature. Low-temperature results show that any intrinsic effect of DW’s scattering on MR of this material is very small compared to the anisotropic MR.