Isothermal crystallization of iron-based amorphous alloys in a high magnetic field

Isothermal crystallization of soft magnetic Fe-Si-B amorphous alloys under high magnetic fields was investigated by magnetization measurements. The increase of magnetization due to the precipitation of ferromagnetic α-Fe(Si) from the paramagnetic amorphous matrix was observed as a function of time. The magnetic field dependence of the time evolution of the crystallization was also examined. The relaxation time increases under high applied magnetic fields indicating that the suppression of the precipitated crystal growth rate occurs. Moreover, by normalizing the relaxation time of the crystallization, the time evolutions of the crystallized fraction converge to a universal sigmoidal curve regardless of the applied magnetic field strength. These behaviors indicate that the magnetic field influences the growth rate rather than the elementary processes of crystallization.