Ni participation in the magnetism of Fe-Ni-Si-B amorphous alloys

/sup 61/Ni Moessbauer measurements at 4.2 K have been performed on (Fe/sub x/Ni/sub 1-//sub x/)/sub 77/Si/sub 10//sub 13/ amorphous alloys with x = 0.0, 0.1, and 0.9. Ni atoms in Ni/sub 77/Si/sub 10/B/sub 13/ bear no magnetic moment, whereas in (Fe/sub 0.1/Ni/sub 0.9/)/sub 77/Si/sub 10/B/sub 13/ and (Fe/sub 0.9/Ni/sub 0.1/)/sub 77/Si/sub 10/B/sub 13/ their moments are, respectively 0.38..mu../sub B/ and 0.65..mu../sub B/. Our results, together with the literature data, show that Ni atoms in Fe-Ni-M (M denotes a metalloid) amorphous alloys do carry a magnetic moment.