The structure of Al2O3 implanted with iron at 77 K

Abstract

Implantation of iron in the fluence range of 1 × 1016 to 1 × 1017 ions/cm2 (160 keV) produces an amorphous surface layer in Al2O3 if the substrate temperature is approximately 77 K during implantation. Conversion electron Mössbauer spectroscopy (CEMS) measurements on the implanted 57Fe show a distribution of the iron among the charge states of Fe2+, Fe0, and the unusual Fe4+ state. The Mössbauer parameters indicate that there are two Fe2+ and two Fe4+ states present in amounts that vary with fluence. No Fe3+ was detected. The fine structure of the electron energy loss spectra indicates that the short-range order in amorphous Fe-implanted Al2O3 differs from that in amorphous Al203 created by ..