Magnetoresistance, Micromagnetism and Domain Wall Effects in Epitaxial Fe and Co Structures with Stripe Domains

TL;DR

This paper reviews magnetotransport and micromagnetic studies of epitaxial Fe and Co thin films with stripe domains, highlighting the dominant role of micromagnetic structure and resistivity anisotropy in low field magnetoresistance and observing a novel negative domain wall contribution in Fe.

Contribution

It provides new insights into the effects of micromagnetic structure and domain walls on magnetoresistance in epitaxial Fe and Co microstructures, including a novel negative domain wall contribution in Fe.

Findings

Micromagnetic structure and resistivity anisotropy dominate low field MR.

Domain wall effects are small but observable, with DW-MR less than 1%.

Negative DW contribution to resistivity observed in Fe at low temperature.

Abstract

We review our recent magnetotransport and micromagnetic studies of lithographically defined epitaxial thin film structures of bcc Fe and 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 $\lesssim 1 %$). 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.