On the metallic behavior of Co clusters Article uri icon

abstract

  • The role of structure in the nonmetal-metal transition of Co clusters is investigated by performing calculations for different symmetries: hexahedral, octahedral and decahedral. This transition occurs when the density of states at the Fermi level exceeds l/kBT and the discrete energy levels begin to form a quasi-continuous band. The electronic structure is calculated including spd orbitals and spillover effects in a Hubbard Hamiltonian solved within the unrestricted Hartree-Fock approximation. We find that in small clusters (N ≤ 40) the metallic behavior is strongly related to the geometrical structure of the cluster. We compare our results with those coming out of a simple Friedel%27s model. © 1999 Elsevier Science Ltd. All rights reserved.
  • The role of structure in the nonmetal-metal transition of Co clusters is investigated by performing calculations for different symmetries: hexahedral, octahedral and decahedral. This transition occurs when the density of states at the Fermi level exceeds l/kBT and the discrete energy levels begin to form a quasi-continuous band. The electronic structure is calculated including spd orbitals and spillover effects in a Hubbard Hamiltonian solved within the unrestricted Hartree-Fock approximation. We find that in small clusters (N ≤ 40) the metallic behavior is strongly related to the geometrical structure of the cluster. We compare our results with those coming out of a simple Friedel's model. © 1999 Elsevier Science Ltd. All rights reserved.

publication date

  • 1999-01-01