MIXING EFFECT OF FE NI MULTILAYERS OF OVERALL FE65NI35 COMPOSITION/

UHV evaporated Fe65Ni35 multilayers were irradiated with 200 keV Kr io ns at doses in the range 1 x 10(15)-5 x 10(16) ions/cm2 in order to fo llow the mixing process as a function of the fluence. The samples were analysed by XRD (glancing angle), RBS and CEMS techniques. Both XRD p atterns and CEM spectra show that a partial bcc to fcc phase transform ation occurs even at the lowest irradiation dose and goes on when the irradiation dose is increased. A remarkable enhancement of the fcc lat tice parameter, due to interstitial inclusions of Kr atoms occurs at 4 x 10(16) Kr2+/cm2 dose. At this dose the analysis of the CEM spectrum exhibits an important component, attributed to the Invar phase, and a vanishing central nonmagnetic component, due to fcc iron rich alloy.