Crystallization, magnetization and scaling: Study of magnetic relaxation in amorphous Fe₈₃B₁₂Si₅

We have investigated the crystallization of amorphous Fe₈₃B₁₂Si₅ by measuring the time evolution of the magnetization for isotherms 634 K ≤ T ≤ 666 K. The rate of growth of the crystalline phase increases with increasing temperature but all growth curves collapse to a universal function when the time is scaled by a factor τ(T). The shape of the universal curve, which is consistent with the Kolmogorov-Johnson-Mehl-Avrami model for nucleation and growth, suggests a diffusion-controlled growth mechanism for this amorphous system.