The local magnetism of Fe impurity in Nb n and Nb nMo m clusters

Abstract

The local magnetic properties of impurity Fe in small Nb n and Nb n Mo m clusters have been studied by using a linear combination of atomic orbitals approach with the density functional formalism, and the Kohn–Sham equation is solved self-consistently with the discrete variational method (DVM). For Nb n Fe ( n=6–18) clusters with O h symmetry, it is found that the local moment of impurity Fe is a monotonous decent function of cluster size and converges to zero as number of atoms exceeds 15, when extrapolating from a finite cluster to an infinite system, we can obtain that a single Fe atom in Nb bulk would be non-magnetic. Mo and Nb have different roles on the local moments of impurity Fe: Mo enhances the moment whereas Nb suppresses the moment. In order to see the general trends of the local moments for Fe impurity in all the 4d series clusters, the calculations and discussions are also performed on 13-atom clusters with I h symmetry.