Local structure and magnetism of Co~(3+) in wurtzite Co:ZnO

摘要

The structural and magnetic properties of 30% and 50% Co-doped ZnO have been investigated in order to determine the influence of the presence of Co~(3+) as a potential p-type dopant. For 30% doping, Co~(3+) could be stabilized in the wurtzite lattice of ZnO without phase separation by providing high oxygen partial pressures during growth. At 50% Co concentration, the crystal lattice destabilizes. X-ray absorption spectroscopy and simulations are used to substantiate the valence and local structure of Co~(3+). Integral and element selective magnetometry reveals uncompensated antiferromagnetism of the Co atoms irrespective of being present as Co~(2+) or Co~(3+).