The activation energy of crystallization of amorphous Fe40Ni40P14B6

The isothermal crystallization of Fe₄₀Ni₄₀P₁₄B₆ (Metglas 2826) has been studied by transmission electron microscopy, using static observations of partially crystallized ribbons at room temperature and in situ dynamic registration of the crystallization process at elevated temperatures. At all temperatures crystallization takes place by the nucleation and growth of individual crystals. Analysis of the transformation kinetics allowed to determine the nucleation rates and the activation energy for crystal growth. The growth velocity of the crystal phase was found to be controlled by the diffusion coefficient of phosphorus in this alloy withD ₀=2.5×10^10±1cm{swu2}/s andQ=(3.4±0.15)eV.