MAGNETIC-PROPERTIES OF TRANSITION-METAL ATOMS ADSORBED ON GRAPHITE

Within an extra-orbital tight-binding approach for the electronic stru cture and a Born-Mayer term for the repulsion, we study the stable pos ition of transition metal atoms on graphite. The hopping integrals bet ween the adatom and the graphite atom are obtained through atomistic c alculations. The energy levels are chosen so as to satisfy Friedel's s creening rule and give rise to the occurrence of high peaks in the den sity of states at the Fermi energy. The Hartree-Fock approximation has been used for the determination of the corresponding spin-polarized e lectronic structure. Recent photoemission experiments on vanadium clus ters adsorbed on graphite displayed satellite peaks in core level XPS spectra which have been tentatively related to a possible onset of mag netism. This interpretation is discussed and compared with a usual sat ellite peak effect due to a core hole potential within an impurity And erson model.