TEMPERATURE-DEPENDENCE OF THE MOSSBAUER-SPECTRA OF AMORPHOUS AND NANOCRYSTALLIZED FE86ZR7CU1B6

Mossbauer measurements have been performed on amorphous and nanocrystalline alloy ribbons of nominal composition Fe86Zr7Cu1B6. The nanocrystalline samples were obtained by annealing the as-quenched alloy at different temperatures in the range between 650 and 870 K. Mossbauer spectra of the as-quenched amorphous sample have been recorded at 77 K, room temperature and above the Curie temperature (approximate to 330 K) at 360 K. We have also performed Mossbauer measurements at room temperature in the nanocrystalline alloys to characterize the phases that appear after the annealing and their relative concentration. The as-quenched sample spectra reveal the existence of two inequivalent sites for Fe. Such a feature is also observed in the remaining amorphous phase of the annealed samples. In the first steps of crystallization, alpha-Fe precipitates and its concentration increases with the annealing temperature. The experimental results suggest that the composition of the whole amorphous phase does not suffer large changes during crystallization.