Magnetic properties of finite Fe chains at fcc Cu(001) and Cu(111) surfaces

We present a systematic study of the magnetic moments and magnetocrystalline anisotropy of finite monoatomic Fe-n (1less than or equal tonless than or equal to9) chains deposited along the (1 (1) over bar0) direction on top of fcc Cu(001) and Cu(111) surfaces as well as embedded into the uppermost three surface layers and into a perfect copper bulk host. The calculations are performed fully relativistically using the embedding technique within the Koninga-Kohn-Rostoker method. We focused our investigations on the effect of the interaction between the Fe atoms as well as between the Fe and host atoms on the magnetic properties of the chains. We found that the calculated spin and orbital moments in the Fe chains are systematically larger than in the corresponding monolayer. Exploring the magnetic anisotropy properties of these systems we obtained a strong out-of-plane easy axis for wires deposited both on the Cu(001) and Cu(111) surfaces, while for the embedded chains the orientation of the easy axis depends on the distance from the surface. We also found remarkable anisotropies for two different in-plane magnetic orientations: namely, for the one parallel and the other perpendicular to the chains.