An insight into the structures, stabilities and magnetic properties of Fe2Bn (n = 1–10) clusters

Abstract

The geometries, stabilities, magnetic and electronic properties of Fe2Bn clusters, up to n = 10, have been systematically investigated by spin-polarized density functional theory calculations. For the small size clusters (n < 6), the most stable Fe2B2 has a distorted tetrahedron geometry, while Fe2B3 and Fe2B4 prefer the bipyramidal structure. The lowest-energy isomers of Fe2B5 prefer the planar structure. When n = 6, all the lowest-energy isomers of Fe2Bn have bipyramid-shaped structure. Fe2B6 and Fe2B7 were confirmed as the magic number clusters, which are more stable than the neighbour sizes. All the Fe2Bn clusters have non-zero spin moments except for Fe2B4, which were remarkable different from the FeBn clusters. The relationship between the spin moment of Fe2Bn and electronic structure was discussed. We also found that the spin polarization at frontier orbitals of Fe2B6 is similar to that of bipolar magnetic semiconductors, while that of Fe2B7 similar to a half semiconductor.