Step-induced in-plane orbital anisotropy in FeNi films on Cu(111) probed by magnetic circular x-ray dichroism - art. no. 184405

The effects of nanostructured magnetic Fe65Ni35 films deposited on a vicina l Cu(111) single-crystal surface on the magnetic anisotropy have been studi ed using magnetic circular x-ray dichroism (MCXD) at the Fe L-2.3 edges. In the one-dimensional (1D) limit a large dipolar out-of-plane anisotropy is evidenced with in-plane isotropic magnetic moments. After the 1D coalescenc e the orbital moment shows a more complex behavior depending on the in-plan e direction of saturation. We show that MCXD is strongly sensitive to in-pl ane orbital anisotropy for the 1D stripes. We demonstrate the importance of the step induced in-plane anisotropy by measuring the orbital magnetic mom ent dependence as a function of the in-plane azimuth angle. In the submonol ayer regime an in-plane magnetic anisotropy is observed related to the step decoration growth mode. In the thickness range of 2-4 equivalent monolayer s, 2D coalescence induces a strong in-plane magnetic anisotropy of the magn etic orbital moment. The microscopic origin of the strong in-plane variatio n of M-L has been attributed to magnetocrystalline effects. Strained films give rise to an in-plane magnetic anisotropy energy up to 2 meV/at.. which is larger than those measured out of the plane (0-1 meV/at.).