Crystallization and magnetic properties of Fe/sub 84/B/sub 9/Nb/sub 7/ amorphous ribbons

The amorphous Fe/sub 84/B/sub 9/Nb/sub 7/ and its nanocrystallization have been studied by X-ray, Mossbauer spectroscopy and magnetic moment measurements. The average hyperfine field H/sub hf/(T) of the amorphous state shows a temperature dependence of [H/sub hf/(T)-H/sub hf/(0)]/H/sub hf/(0)=-0.52 (T/T/sub C/)/sup 3/2/-0.34 (T/T/sub C/)/sup 5/2/ for T/T/sub C/<0.7 indicative of spin-wave excitation. The quadrupole splitting just above the Curie temperature T/sub C/ is 0.41 mm/s, whereas the average quadrupole shift below T/sub C/ is zero. The Curie and crystallization temperatures are determined to be T/sub C/=330 K and T/sub x/=750 K respectively, for a heating rate of 5 K/min. The occupied area of the nanocrystalline phase at the optimum annealing temperature is about 73%.