Swift heavy ion induced formation of alpha-FeSi2

Irradiation experiments of thin Fe-57 layers on Si with heavy ions in the 1 00 MeV range were performed at RT. The energy loss of the ions in the Fe la yer which is dominated by electronic effects was varied between 32 and 47 k eV/mn. The formation of iron silicide phases was studied by conversion elec tron Mossbauer spectroscopy (CEMS) which delivered very clear phase assignm ents due to the high content of Fe-57 Mossbauer probe nuclei. The exclusive formation of the high temperature alpha-FeSi2 phase was observed in all ir radiations with increasing formation efficiency for increasing energy loss. The occurrence of this phase which is thermodynamically stable above 960 d egrees C may indicate high temperature conditions along the ion tracks. (C) 1998 Elsevier Science B.V. All rights reserved.