Structures, energetics and magnetic properties of (NiSn) n clusters with n = 1–6

Abstract

We report the results of calculations which were performed to investigate equilibrium structures, electronic and magnetic properties of stoichiometric (NiSn) n clusters with n = 1-6 within the framework of density functional theory. The calculated results show that the structural arrangement of (NiSn) n clusters is dominated by the Ni-Sn and Ni-Ni interactions. We find that these binary clusters show significant variation in the geometries as compared to that of the host nickel clusters. The preference for tetrahedron unit of Ni 3 Sn is seen in the lowest-energy configuration of these clusters. The multi-centre bonding between Ni atoms play an important role in stabilizing the stoichiometric Ni-Sn clusters. Doping of Sn atoms enhances the binding energy and reduces the ionization potential of nickel clusters. These binary clusters prefer the lowest spin state. For (NiSn) 6 the magnetic moment is 0 μB. The complete quenching of the cluster magnetic moment appears to be due to the antiferromagnetic alignment of atomic spins as revealed by the spin density plots.