Magnetic surface anisotropy of transition metals

Abstract
A model calculation is presented for the computation of the magnetic surface anisotropy Ks for transition metals. Special reference is made to Ni. It is demonstrated that the changes at the surface in the effective atomic potential of the different d orbitals are very important in determining Ks. Furthermore it is shown that one must include all d orbitals in the calculations. The problem is studied by successively treating the weak-hopping limit, the one-layer problem, and the surface of a semi-infinite crystal. The sign and the order of magnitude of the magnetic surface anisotropy which we find for Ni agree with the experimental results on Ni alloys. A comparison is made to earlier work on the subject.