Structures, energetics, and magnetic properties of Ni_nB clusters with n=1-8,12

Abstract

We report the results of calculations which were performed to investigate equilibrium structures, electronic and magnetic properties of small Ni_nB clusters with n=1-8,12 within the framework of density functional theory. The calculated results find that doping of boron enhances the binding energy but reduces the magnetic moments of Ni clusters. The boron prefers to maximize the number of Ni-B bonds by selecting the site which increases the coordination of nickel atoms with B, and is seen to induce significant changes in the geometries of the host clusters for n<4. This study also reveals that some of the Ni_nB clusters considered have a substantial higher highest ocupied-lowest unoccupied molecular orbital gap of spin-up electrons as compared to that of spin-down electrons. This may have interesting consequences in the case of the spin-polarized transport, where there will be no conductance for spin-up electrons in such Ni_nB clusters.