Abstract:
As regards the magnetic properties of dilute magnetic semiconductors, Co-doped ZnO is still one of the puzzling specimen. We investigated the nature of the magnetic coupling by means of density functional theory, and found it to be localized to the nearest neighbors. Studying different spatial arrangements of the Co atoms, we observe that there is a clustering tendency among them, which is coupled to antiferromagnetic interactions within the cluster. The change in the magnetic properties by Al codoping is also discussed.