Effects of oxygen vacancy on magnetic properties of cobalt-doped zno dilute magnetic semiconductors

摘要

Effects of oxygen vacancy (Vo) on magnetic properties of Co-doped ZnO are investigated by first principle calculations. The calculated formation energies of Vo with different bonding to Co atom indicate that Vo prefers location near Co atom, implying a strong local interaction between the Co atom and O-vacancy. Induced by Vo, the Co-3d and O-2p valence bands upward shift towards the Fermi level, leading to the presence of additional carriers at the Fermi level. The delocalized carriers and the substitutional Co ion play a key role in the occurrence and stability of ferromagnetism of Co-doped ZnO.