Structural, electronic and magnetic properties of Mn, Co, Ni in Gen for (n=1–13)

The structural, electronic and magnetic properties of TMGen (TM=Mn, Co, Ni; n  =1–13) have been investigated using spin polarized density functional theory. The transition metal (TM) atom prefers to occupy surface positions for n<9n<9 and endohedral positions for n≥9n≥9. The critical size of the cluster to form endohedral complexes is at n=9, 10 and 11 for Mn, Co and Ni respectively. The binding energy of TMGen clusters increases with increase in cluster size. The Ni doped Gen clusters have shown higher stability as compared to Mn and Co doped Gen clusters. The HOMO–LUMO gap for spin up and down electronic states of Gen clusters is found to change significantly on TM doping. The magnetic moment in TMGen is introduced due to the presence of TM. The magnetic moment is mainly localized at the TM site and neighbouring Ge atoms. The magnetic moment is quenched in NiGen clusters for all n except for n=2, 4 and 8.