First-principles study of magnetic properties in V-doped ZnO

A comprehensive theoretical study of electronic and magnetic properties of V-doped ZnO in bulk as well as (11 (2) over bar0) thin films has been performed using density functional theory. Vanadium atoms substituted at Zn sites show very little selectivity of site occupancy. More importantly, different geometries with ferromagnetic, ferrimagnetic, and antiferromagnetic configurations are found to be energetically nearly degenerate both in Zn1-xVxO bulk and subsurface layers of the thin film. On the other hand, V atoms couple ferromagnetically when they occupy surface sites of the thin film. The diverse magnetic behaviors in V-doped ZnO account for the many reported conflicting experimental results. (c) 2007 American Institute of Physics.