Magnetic properties of small Yttrium clusters

The magnetic properties of small YN clusters are studied by using a tight-binding Hubbard Hamiltonian in the unrestricted Hartree-Fock approximation. Several types of cluster geometries are considered in order to see the effects of the size and symmetry of the structures on the magnetic properties. The average magnetic moments 〈M〉 are found to be constant over large domains of variations in the interatomic distance, a fact that can be explained by the existing closed shell electronic configurations at least for one spin direction in all our magnetic solutions. Small energy gains upon the onset of magnetization are obtained, which reveals the low stability of the magnetic solutions. Our results contradict the prediction of a magnetic-nonmagnetic transition at a large cluster size (about 90 atoms) for these kinds of systems.

36.40.Cg Electronic and magnetic properties of clusters; 61.46, w Clusters, nanoparticles, and nanocrystalline materials Approximation theory; Crystal atomic structure; Crystal symmetry; Electronic structure; Magnetic moments; Magnetic properties; Magnetization; Nanostructured materials; Hartree-Fock approximation; Tight-binding Hubbard Hamiltonians; Yttrium
36.40.Cg Electronic and magnetic properties of clusters; 61.46,+w Clusters, nanoparticles, and nanocrystalline materials Approximation theory; Crystal atomic structure; Crystal symmetry; Electronic structure; Magnetic moments; Magnetic properties; Magnetization; Nanostructured materials; Hartree-Fock approximation; Tight-binding Hubbard Hamiltonians; Yttrium

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