Structure and magnetic properties of cobalt doped Sin (n=2-14) clusters

The structure and magnetic properties of cobalt doped Sin (n=2-14) clusters have been systematically studied using density functional theory (DFT). For each cluster size, extensive search of the lowest-energy structure has been conducted by considering a number of structural isomers. The equilibrium site of the Co atom in the ground-state structures of SinCo clusters gradually moves from convex, surface, to interior sites as the number of Si atom increases from 2 to 14. Starting from Si10Co, Co atom is fully encapsulated by the Si outer cages. The magnetic moment of Co atom in SinCo clusters is completely quenched at n=7, due to charge transfer and strong hybridization between 4s and 3d states of Co and 3s and 3p states of Si.