Shape effect on the magnetic anisotropy of an array of epitaxial (10/spl middot/0) Co dots

The competition between the magnetocrystalline and shape anisotropies was studied by using a submicron-size epitaxial (10/spl middot/0) Co rectangular dots array. The measured torque curves exhibit the magnetic anisotropy with a four-fold symmetry, indicating a clear magnetic easy-axis reorientation. The results were successfully interpreted by taking into account the first order magnetocrystalline, shape and non-negligible second order magnetocrystalline anisotropies.