Vibrational states of hexagonal ZnO doped with Co

Vibrational density of states of 12.5% cobalt doped bulk hexagonal ZnO has been studied using the density functional theory method. It has been shown that introduction of cobalt into ZnO leads to appearance of additional vibrational modes with their frequencies dependent on the relative positions of cobalt atoms. The magnetic and vibrational properties have been studied in highly Co-doped ZnO samples that are characterized by a high possibility of metal clusters formation.