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

Abstract

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. © 1999 The American Physical Society.