Neutron irradiation effect on magnetic properties of Cr-, Mo- and Si-doped FeNi-alloys

Sample of FeNi, FeNi: Cr, FeNi: Mo, and FeNi: Si alloys were irradiated by neutron beams in the vicinity of a 2 MW reactor core and their magnetic hysteresis curves, magnetic after effects as well as variations of magnetic permeability with temperature were determined. From these curves Curie temperature shift, spectrum width k, and activation energy for self-diffusion of Fe and Ni atoms were obtained. The presence of Si impurities in the FeNi alloy produces a considerable attenuation in the vacancy supersaturation and the analysis of the spectrum width in this sample indicates that the defect structure due to neutron irradiations is more complex than that due to thermal effect. (author)