Abstract
We present first-principles results for Sc-doped ZnO thin films. Neighboring Sc atoms in the surface and/or subsurface layers are found to be coupled ferromagnetically, where only two of the possible configurations induce spin polarization. In the first configuration, the polarization is carried by the Sc d states as expected for transition metal doping. However, there is a second configuration which is energetically favorable. It is governed by polarized hybrid states of the Zn s, O p, and Sc d orbitals. Such highly delocalized states can be an important ingredient for understanding the magnetism of doped ZnO thin films. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4721807]