Fe3C nanoparticle formation in Fe implanted HOPG and CVD diamond

We have conducted conversion electron Mossbauer spectroscopy (CEMS) studies of Fe-carbides produced in Fe implanted highly oriented pyrolytic graphite (HOPG) and CVD diamond substrates. The samples were implanted at room temperature with Fe-57 ions with 40 keV and 60 keV, respectively, and corresponding fluences of 1.0.10(16)/cm(2) and 5.10(15)/cm(2). The formation of magnetic structures in the spectra was monitored with CEMS measurement after annealing the samples at temperatures up to 700 degrees C. After the high temperature annealing, the main components in the spectra were sextets whose line shapes displayed strong, asymmetric distortions, consistent with those due the formation of nanoclusters. The hyperfine magnetic fields B-hf = 21.6 T, 20.0 T and 18 (1) T were in good agreement with those observed previously for Fe3C nanoclusters 10-20 nm in size.