Radiogenic Sn impurity defects in germanium

Sn impurity defect structures in germanium have been investigated by Moessbauer emission spectroscopy on the 24 keV γ-radiation of 119Sn. The defects have been created by ion implantation of radioactive 119In+ and 119Sb+ which both populate the Moessbauer level of 119Sn in their decays. From the Moessbauer parameters (hyperfine structure and Debye-Waller factor) determined, the Sn atoms are concluded to be incorporated in a number of different defect structures. For both implantations of 119In and 119Sb, large substitutional fractions are found. An interstitial fraction, which is attributed to non-bonding interstitial sites of the Sn atoms, is identified. Three further defect structures, each found for either 119In is identified. Three further defect structures, each found for either 119In or 119Sb implantations only, are attributed to different Sn-vacancy complexes. For 119In implantations, one complex is proposed to be a (substitutional) Sn-vacancy pair characterized by a dangling bond at the Sn atom. For 119Sb implantations, more than one vacancy is associated to the impurity atoms, which is proposed to result in a structurally different defect. A third impurity-vacancy defect type found for 119In implantations is modelled to consist of interstitial Sn atoms in the center of a divacancy. The three vacancy complexes anneal at different annealing temperatures. (Auth.)