Influence of deposition field on the magnetic anisotropy in epitaxial Co70Fe30 films on GaAs(001)

The effect of the application of a magnetic field during deposition of epitaxial Co{sub 70}Fe{sub 30} onto GaAs(001) is shown; we find an initially counterintuitive result. For field applied along the interfacial uniaxial hard axis the relative effective uniaxial magnetic anisotropy is increased by a factor of two in comparison to both field along the uniaxial easy axis, or no field; usually, application of a deposition field results in a uniaxial easy axis parallel to this field direction. We show that the deposition field changes the maximal projection of the atomic orbital magnetic moments onto the easy axis, which corresponds to a deposition field induced shift in the Helmholtz free-energy landscape of the system.