An Unusual Iron Site in Iron-Doped Zinc Oxide

Abstract

Both divalent and trivalent iron have been substituted into the zinc oxide lattice at levels up to about 2.5 atomic percent. Using enriched57Fe, Mössbauer studies indicate that either Fe2+or Fe3+may substitute for Zn2+at its normal lattice site. One spectrum indicative of Fe3+is observed when iron is substituted into zinc oxide under oxidizing conditions. However, two distinct spectra are found for Fe2+when iron is substituted into zinc oxide under reducing conditions. The quadrupole splitting of one of these Fe2+spectra shows an exceptionally high temperature dependence.