Tuning electronic and magnetic properties of endohedral Co@B80 and exohedral Co-B80 metallofullerenes by positioning Co atom

We have performed a systematical study of the structural configurations, electronic and magnetic properties of the single Co-doped endohedral Co@B-80 and exohedral Co-B-80 metallofullerene complexes using spin-polarized density functional calculations. Our calculations revealed that there are four stable configurations of the Co-doped metallofullerenes depending on different positions of the doping Co atoms as follows. In the case of the exohedral Co-B-80 metallofullerene complexes, Co atom energetically prefers standing near the centers of pentagon (pentagon-out) and hexagon (hexagon-out) on the surface of B-80. In the case of the endohedral Co@B-80 metallofullerene complexes, the encapsulated Co atom energetically prefers standing near the centers of pentagon (pentagon-in) and hexagon (hexagon-in) on the inner surface of the hollow cage of B-80. Electronically, the energy gaps of the hexagon-near adsorbed metallofullerenes have been greatly modified compared with that of B-80. At the same time, the magnetic moments of both of the exohedral Co-B-80 metallofullerenes are one third of that of the isolated Co atom. The tunable electronic and magnetic properties of the Co-doped B-80 metallofullerenes clearly showed that this new type of metallofullerenes may be a promising candidate for molecular devices, especially single molecular spin electronic devices. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3431522]