Thermal evolution of high dose Fe implanted Si(100) at 623 K: a CEMS study

Hyperfine interactions associated to the phases produced by 623 K Fe implantation into Si(100) and by subsequent thermal treatments at temperatures up to 1273 K have been studied by conversion electron Moessbauer spectroscopy. The results suggest that in the as implanted sample the short range order around the 57Fe probes is β-FeSi2-like. This phase orders with a thermal treatment at 773 K. A preferential orientation of the electric field gradient was detected from the relative height of the quadrupole interaction components. It was found that the transition to the high temperature phase α-FeSi2 occurred at least 50 K below the reported value. (orig.)