Magnetoresistance, micromagnetism, and domain wall effects in epitaxial Feand Co structures with stripe domains (invited)

We review our recent magnetotransport and micromagnetic studies of lithogra phically defined epitaxial thin film structures of body-centered-cubic Fe a nd hexagonal-closed-packed (hcp) Co with stripe domains. Micromagnetic stru cture and resistivity anisotropy are shown to be the predominant sources of low field magnetoresistance (MR) in these microstructures, with domain wal l (DW) effects smaller but observable (DW- MR less than or similar to 1%). In Fe, at low temperature, in a regime in which fields have a significant e ffect on electron trajectories, a novel negative DW contribution to the res istivity is observed. In hcp Co microstructures, temperature dependent tran sport measurements for current perpendicular and parallel to walls show tha t any additional resistivity due to DW scattering is very small. (C) 1999 A merican Institute of Physics. [S0021-8979(99)65208-2].