LAUSR

AbstractThe geometries, stabilities, and magnetic properties of Co2Bn (n = 1–10) clusters were systematically investigated by performing spin-polarized density functional theory calculations. We found that doping Bn clusters with Co significantly changed their structures. Co2B2 and Co2B5 had planar and quasi-planar structures, while Co2B3 and Co2B7 had bipyramidal structures. Co2B10 had a tubular structure. In analyses of the dissociation energies and the second-order differences in total energy of the clusters, Co2B3 and Co2B7 were identified as magic-number (i.e., unusually stable) clusters. All of the Co2Bn clusters had nonzero spin magnetic moments except for Co2B10. Among the Co2Bn clusters, Co2B and Co2B7 had the largest spin magnetic moments (3 μB). The 3d orbital of Co was the main contributor to the spin magnetic moments of the Co2Bn clusters. The two Co atoms exhibited ferromagnetic alignment in all of the Co2Bn clusters except for Co2B9. Graphical abstractThe magic-number cluster Co2B7 has bipyramidal structure and the Co2B10 has tubular structure