AN UNUSUAL IRON SITE IN IRON-DOPED ZINC-OXIDE

Both divalent and trivalent iron have been substituted into the zinc o xide lattice at levels up to about 2.5 atomic percent. Using enriched Fe-57, Mossbauer studies indicate that either Fe2+ or Fe3+ may substit ute for Zn2+ at its normal lattice site. One spectrum indicative of Fe 3+ is observed when iron is substituted into zinc oxide under oxidizin g conditions. However, two distinct spectra are found for Fe2+ when ir on is substituted into zinc oxide under reducing conditions. The quadr upole splitting of one of these Fe2+ spectra shows an exceptionally hi gh temperature dependence. (C) 1996 Academic Press,Inc.