FMR STUDY OF CRYSTALLIZATION IN THE METGLAS 2826 AMORPHOUS ALLOY

The ferromagnetic resonance technique was used to study the annealing behavior of the metallic glass Fe//4//0Ni//4//0P//1//4B//6 (Metglas 2826). The peak-to-peak FMR linewidth, DELTA H//p//p, was measured at room temperature and 9. 5 GHz for several times of isothermal annealing in the temperature range 350-375 degree C. After an initial decrease, attributed to structural relaxation, the linewidth increases with annealing time for all temperatures investigated. The activation energy for crystallization, E//c, is estimated from the times to DELTA H//p//p equals 20 to 80 mT as (412 plus or minus 23) kJ/mol. The results suggest that, for sufficiently long annealing times, there is a well-defined relation between DELTA H and the volume fraction of the transformed phase.