Impurity-defect complexes in ion-implanted aluminum

The formation of impurity-defect complexes in ion-implanted aluminium has been studied in the temperature interval 100-400K. Radioactive 119In isotopes have been implanted. Moessbauer spectra have been measured for the 24 keV γ-radiation emitted after the decay to 119Sn. The spectra could be analysed satisfactorily with two lines, one which is known to be due to substitutional Sn. A second line, which has a higher isomer shift and lower Debye temperature, is tentatively assigned to vacancy-associated Sn, formed by trapping of thermally mobile (multi-) vacancies. Comparison to similar DPAC experiments suggests that cubic Sn-V4 complexes are formed. Some indication for an athermal formation of impurity defects below 175K is obtained. (Auth.)