Structural, electronic and magnetic properties of Fen@C60 and Fen@C80 (n=2-7) endohedral metallofullerene nano-cages: First principles study

We studied the structural, electronic and magnetic properties of small Fen clusters (n=2-7) endohedrally doped in icosahedral C-60 and C-80 fullerenes using first principles calculations based on the density functional theory. It is found that the encapsulated Fe-n clusters inside icosahedral C-80 are energetically favorable while Fe-n@C-60 metallofullerene nano-cages are not. The binding energies of the Fe-n encapsulated in C-60 are positive and increase with the number of iron atoms (n) while those of the Fe-n@C-80 are negative and their absolute values increase up to n=6. The encapsulation does not significantly change the enclosed cluster structure, but the total magnetic moment of the larger clusters reduces due to a stronger Fe-C hybridization. (C) 2011 Elsevier B.V. All rights reserved.