Influence of Roughness on Magnetic Surface Anisotropy in Ultrathin Films
Journal
Journal of Applied Physics
Journal Volume
72
Journal Issue
2
Pages
596-600
Date Issued
1992
Author(s)
Abstract
A magnetostatic model for shape anisotropy of an ultrathin film with surface roughness is presented. Apart from the usual volume anisotropy, an additional perpendicular surface anisotropy results from the surface roughness. For a continuous film, the shape anisotropy follows the famous 1/t behavior. By considering the correlation between the surfaces, the perpendicular surface anisotropy can be further increased. When the film thickness is less than a certain value, the magnetic layer may become a discontinuous or island-like structure and the shape anisotropy is proportionally lower with decreasing film thickness. With a nonzero quality factor (Q=Kc/2πMs2), a marked kink in the dependence Kefft on the film thickness gradually appears with increasing roughness. Observed results agree qualitatively with predictions based on the present model.
SDGs
Type
journal article