For Fusion energy applications FeCr ferritic martensitic steels are candidate structural materials due to their radiation resistance and good mechanical properties. Thus, the understanding of the neutron irradiation effects on FeCr steels is of paramount importance for the development of radiation resistance materials. The damage induced in the material by fusion neutrons of 14 MeV can be imitated employing self-ion irradiation. Recent polarised neutron reflectivity measurements of Fe+ ion irradiation of Fe-10at%Cr films have shown an increase of the magnetic moment of the FeCr matrix with the increase of the irradiation dose. This effect is attributed to the Cr depletion of the matrix which is in indication of Cr precipitation. With the current proposal the investigation will be extended to Fe+ ion irradiated Fe-15at%Cr films, since Cr is expected to affect these phenomena.