Kink contribution to the magnetic anisotropy of nanostructured ultrathin Co/Cu(001) and Fe/Ag(001) films

We have investigated the surface kink contribution to the in-plane magnetic anisotropy of nanostructured ultrathin Co/Cu(001) and Fe/Ag(001) films. We have exploited the ion sculpting technique to induce the formation of nanosized surface ripples misaligned with respect to the high-symmetry crystallographic directions, thus obtaining a controlled distribution of surface steps and kinks departing from the fourfold-symmetric equilibrium one. The imbalance in the densities of the differently oriented kinks thus generated allows to underscore the magnetic anisotropy of atoms at kink sites. We find that atoms at kink sites at the surface of Fe/Ag(001) films give an overall uniaxial contribution to the in-plane magnetic anisotropy with easy axis oriented along the <110> directions, while no sizable kink contribution has been observed in the case of Co/Cu(001) films.