MAGNETIC-ANISOTROPY OF FEXCO1-X, MULTILAYERS ON CU(001) - REORIENTATION TRANSITION OF MAGNETIC-MOMENTS DUE TO DIFFERENT INTERLAYER COUPLING

The magnetic anisotropy energies of FexCo1-x multilayers on Cu(001) ha ve been determined by means of ab initio calculations using the fully relativistic, spin-polarized screened Korringa-Kohn-Rostoker method wi thin the local spin density approximation. By utilizing the coherent p otential approximation the Fe/Co system was treated within a mean-fiel d approach as a (uniform) randomly disordered alloy. The type of magne tic interlayer coupling-either ferromagnetic or antiferromagnetic-that is energetically more favorable is found to depend on both the film t hickness and alloy composition. It seems therefore that the type of ma gnetic interlayer coupling is also responsible for the reorientation t ransition mainly because of the strong enhancement of the band energy contribution to the magnetocrystalline anisotropy energy in the case o f antiferromagnetic coupling.