  In using the fully relativistic versions of the Embedded Cluster and Screened
Korringa-Kohn-Rostoker methods for semi-infinite systems the magnetic
properties of single adatoms of Fe and Co on Ir(111) and Pt(111) are studied.
It is found that for Pt(111) Fe and Co adatoms are strongly perpendicularly
oriented, while on Ir(111) the orientation of the magnetization is only
out-of-plane for a Co adatom, for an Fe adatom it is in-plane. For comparison
also the so-called band energy parts of the anisotropy energy of a single layer
of Fe and Co on these two substrates are shown. The obtained results are
compared to recent experimental studies using e.g. the spin-polarized STM
technique.
