In order to treat the orientation of the magnetic field at surfaces properly, the spin-polarized fully relativistic version of the screened Korringa-Kohn-Rostoker method for semi-infinite systems is presented. Magnetic anisotropy energies up to six iron layers on Au(001) are calculated by using the force theorem, predicting a change from a perpendicular to a parallel magnetization for a layer thickness between three and four layers of Fe, in very good agreement with experimental observations. In particular, the magnetic anisotropy energy is discussed in relation to the orbital magnetic moment and to the orientation of the magnetic field when changed continuously.

• Received 13 December 1994

DOI:https://doi.org/10.1103/PhysRevB.51.9552