The Mössbauer search for Fe in Si

In this review paper, a series of Mössbauer experiments on Fe in Si, spread over almost thirty years, is discussed. In early Mössbauer experiments, the role of precipitate formation during diffusion was insufficiently realized. Later, an apparent inconsistency was observed between ion implantation experiments by recoil implantation of Coulomb excited atoms and by conventional ion implantation. This inconsistency is removed by recent high-resolution Coulomb excitation recoil implantation studies and by ion implantation experiments at the temperature of liquid helium. These studies lead to an unambiguous identification of interstitial Fe and Co in Si. Finally, the present status of the theoretical predictions on the isomer shift of Fe in Si is reviewed.