Magnetismo en cúmulos de metales de transición 4d

The magnetic properties of rutenio (RuN), rhodio (RhN) and paladium (PdN) clusters are determined as function of the cluster size N (N = 4, 6, 13 and 19). For N = 4 and 6 we take the tetrahedrol end pentagonal pyramid geometric structures respectively. For N = 13 and 19 we consider fcc-like structures. We use a tight-binding Hamiltonian for s, p and d electrons in the unrestricted Hartree-Fock approximation. For the considered cluster, we obtain magnetic moments non-vanishing local, with the exception of Rh4. RuN and RhN present a maximum in the average magnetic moment when the size of the cluster is N = 13 and in all the elements we found that the average magnetic moment decreases strongly at N = 19. As espected, the lacal magnetic moments at the atoms of the surface of the cluster are larger than those at inmer atoms, except for Ru19. We find strong oscillations of the magnetic moment as function of N an are less important in the PdN clusters.

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