Effects of irradiation with inert and reactive gas ions on the Fe and Cr thin film structure

High-purity, thin polycrystalline Fe and Cr films, deposited in vacuum (2-3)·10 −6 Pa, were irradiated at room temperature with various inert (Ne + , Ar + , Kr + , Xe + ) and reactive (N + , O + ) gas ions to doses of (2-3)·10 17 cm −2 at energies ranging from 35 to 100 keV. The crystal structures of irradiated films were studied by electron diffraction technique. As in the previously investigated case of Ni films, irradiation with inert gas ions is found to cause no changes in the crystal structure of both Fe and Cr films, while irradition with N + or O + ions gives rise to the phases whose structures correspond to nitrides or oxides of the metals under study. On the strength of these data we suggest that the existing notion about a purely radiation nature of ion-induced phase transformation is erroneous.