FMR study of crystallization in the amorphous alloy Co 69Fe 4Ni 1Mo 2B 12Si 12 (Metglas 2705M)

Abstract

The ferromagnetic resonance technique was used to study the annealing behavior of the metallic glass Co 69Fe 4Ni 1Mo 2B 12Si 12 (Metglas 2705M). The peak-to-peak FMR linewidth, Δ H pp, was measured at room temperature and 9.5 GHz for three isothermal annealing times in the temperature range 727–767 K. The transformed fraction, as derived from FMR data, satisfies the Johnson–Mehl–Avrami equation with the exponent n between 1.04 and 1.06. The activation energy for crystallization is estimated from the times to Δ H pp=55–65 mT to be 86 kJ mol −1.