The average hyperfine fields of amorphous Fe70Co20Zr10
Fe80Co10Zn10and Fe86Co4-Zr10 alloys at different temperature were measured by the Mossbauer technique. According to Bloch’s T3/2 relation
spin-wave exitations of above amorphous alloys were studied and their B3/2 values were found to be 0.40±0.02
0.45±0.02 and 0.88±0.04
respectively. Comparing the B3/2 values of crystals
a-Fe-(Co
Ni)-ME
a-Fe-(Cr
Mn
W)-ME and a-Fe-B or TM-Zr Invar alloys
the obvious difference among them was observed. Above results can be explained well by the exchange coupling fluctuation and the disorder of spatial arrangement. In this work
the difference between the stiffness coefficients obtained from the inelastic neutron scattering and the magnetization measurements for amorphous Invar alloys was also explained.