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

We review our recent magnetotransport and micromagnetic studies of lithographically defined epitaxial thin film structures of body-centered-cubic Fe and hexagonal-closed-packed (hcp) Co with stripe domains. Micromagnetic structure and resistivity anisotropy are shown to be the predominant sources of low field magnetoresistance (MR) in these microstructures, with domain wall (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 effect on electron trajectories, a novel negative DW contribution to the resistivity is observed. In hcp Co microstructures, temperature dependent transport measurements for current perpendicular and parallel to walls show that any additional resistivity due to DW scattering is very small. (C) 1999 American Institute of Physics. [S0021-8979(99)65208-2].