Strongly enhanced orbital moments and anisotropies of adatoms on the Ag(001) surface

We present ob initio calculations for orbital moments and anisotropy energi es of 3d and 5d adatoms on the Ag(001) surface, based on density functional theory, including Brooks' orbital polarization (OP) term, and applying a f ully relativistic Korringa-Kohn-Rostoker-Green's function method. In genera l, we find unusually large orbital moments and anisotropy energies, e.g., i n the 3d series. 2.57 mu (B) and +74 meV for Co, and, in the 5d series, 1.7 8 mu (B) and +42 meV for Os. These magnetic properties are determined mainl y by the OP and even exist without spin-orbit coupling.