We investigated the effect of noble gas irradiation (He, Ne, Ar and Xe
) on Fe-Ni multilayers with a very thin modulation and nominal composi
tion in the invar region Fe0.63Ni0.37. The evaluation of the formation
/stability of the Fe-Ni phases formed under irradiation with different
ions and doses was followed by conversion electron Mossbauer spectros
copy. (C) 1997 Elsevier Science B.V.