Structure, valence, and magnetism of Co-doped ZnO at the coalescence limit (invited)

Zn0.8Co0.2O epitaxial films have been grown by reactive magnetron sputtering and investigated with regard to the local structural properties, valence, and magnetism using x-ray absorption spectroscopy and both linear as well as magnetic circular dichroism. Samples were found to be phase pure and paramagnetic even at the coalescence of the Co doping and a small magnetic polarization of the Zn can be inferred. The changes of structure, valence, and magnetism upon increasing the oxygen content in the sputter gas are researched as well. (C) 2014 AIP Publishing LLC.