Analysis of magnetocrystalline anisotropy oscillations in Co/Pd thin films

The oscillations of magnetocrystalline anisotropy (MA) energy with the increasing thickness of a Pd overlayer in Co/Pd systems, obtained within a realistic five-d-band tight-binding model, are analysed thoroughly in order to determine uniquely the basic origin of the oscillations. Several techniques are applied to achieve this goal, including real- and k-space breakdowns of the MA energy. The MA oscillations are shown, in a direct way, to come from pairs of majority-spin quantum-well states, confined in the Pd overlayer, and the corresponding pairs of minority-spin resonances, both occurring near the Fermi level at and in the neighbourhood of the <()over bar> point of the two-dimensional Briilouin zone. The oscillatory behaviour of layer-resolved MA contributions in the Pd overlayer is also explained.