LOCAL FE MOMENTS IN ALPHA-PHASE AND GAMMA-PHASE FE-RICH FE-NI ALLOYS

We have used photoemission measurements of the Fe-3s core level to inv estigate the Fe local moments in two Fe-Ni alloys containing 70% and 7 2.5% Fe in both the gamma- and alpha-phases. Previous magnetization me asurements indicate that in this composition range the average total m oments of alloys in the gamma-phase are considerably lower than in the alpha-phase. However, our photoemission measurements suggest that the local moment on the Fe site is approximately the same in both phases. Furthermore, a determination of the spin-splitting suggests that at r oom temperature the Fe local moments in the alloys are smaller than in pure Fe.