Evaluation of Activation Energy Spectra for Structural Relaxation in Amorphous Fe-Ni-B-Si Alloys by AES Model

Structural relaxation processes have been investigated for Fe60Ni20B10Si10 and Fe50Ni30B10Si10 amorphous alloys by differential scanning calorimetry. The activation energy spectra P(E) for the processes were estimated on the basis of AES (Activation Energy Spectra) model. The spectra (P(E) ) were asymmetric in shape. The P(E) in both the amorphous alloys shifted to the higher side of E with increasing temperature as a result of the contribution of relaxation centers activated at higher temperatures. The activation energies for relaxation over the annealing temperatures investigated were distributed in a range from 164.1 kJ/mol (1.7 eV) to 202.7 kJ/mol (2.1 eV). This explains well that the P(E) results from the relaxation centers in which the short-range rearrangements of metal-metal pairs could take place.