Evidence for interdot coupling in an array of micrometric Fe dots

The magnetization reversal of both the continuous and patterned Fe films, grown in ultra high vacuum byatomicallycontrolled evaporation through a mask, was studied using magneto-optic Kerr magnetometry. The hysteresis loopsrecorded from continuous Fe film as a function of the direction of the applied field, evidence a well-defined uniaxialanisotropy, induced during the film deposition. The patterned area shows a magnetic anisotropy completely differentfrom that of the continuous film and related to the lattice symmetry. Scanning electron microscopy images of thepatterned area allows us to exclude effects related to deviations from circularityof the shape of the single dots. The closerelationship between the anisotropydirections and the pattern lattice axes indicates that the new anisotropyoriginatesfrom the interdot dipolar coupling interaction.r 2003 Elsevier B.V. All rights reserved.