Lattice locations and properties of Fe in Co/Fe co-implanted ZnO

The lattice locations and electronic configurations of Fe in Co/ Fe implanted ZnO (to (5-6) × 10 Fe/cm ) have been studied by Fe Mössbauer emission spectroscopy. The spectra acquired upon room temperature implantation show ~20 of the probe atoms as Fe on perturbed Zn sites and the remaining fraction as Fe in damage sites of interstitial character. After annealing at 773 K, ~20 remain on crystalline sites, while the damage fraction has partly disappeared and instead a ~30 fraction occurs as high-spin Fe , presumably in precipitates. This suggests that precipitation of Co/Fe in ZnO likely takes place at relatively low temperatures, thus explaining some of the discrepancies in the literature regarding magnetic properties of 3d metal-doped ZnO. © 2012 American Institute of Physics.