Stabilities of AlnCu (n=1-19) Clusters and Magnetic Properties of Three Cu-Doped Al Clusters

By using the Amsterdam Density Functional program, we have studied the geometric features, stabilities and magnetic properties of AlnCu (n = 1-19) clusters. The magnetic structures of Al17Cu2 and Al19Cu clusters are found. Although the high spin ground state of Al12Cu cluster is in accordance with the Hund's rule under spherical Jellium model (SJM), it is difficult to explain why the Al17Cu2 and Al19Cu clusters exhibit larger magnetic moments by the model. A superatom model under equivalent charge distribution is proposed. The magnetic properties of the Cu-doped Al clusters can be explained well by combination of the superatom model with SJM.