Magnetism, structure and morphology of thin cobalt films deposited on Cu(1 1 5)

The growth of a cobalt film on a vicinal Cu(1 1 n) surface induces an uniaxial magnetic anisotropy. If the steps are clearly at the origin of this behaviour, the exact mechanism (lower coordination at steps, anisotropic strain) remains obscure. For Co films grown on Cu(1 1 5), a twofold magnetic anisotropy is observed by in situ Kerr effect for thicknesses above 5 monolayers (ML), the easy magnetization axis being always parallel to the step edge. Detailed studies of the morphology by scanning tunneling microscopy and of the structure by Surface EXAFS allow to conclude that the step-induced magnetic anisotropy does not originate from an in-plane anisotropic structural relaxation but is more likely related to the stepped film morphology.