The crystallization evolution and the soft magnetic properties of a a Finemet-like nanocomposite
ribbon, Fe73.5S17.5B 5Nb3Cu1, have been investigated by using differential scanning calorimetry (DSC)
and thermomagnetic measurements. The results show that DSC curve exhibits two clearly exothermal peaks,
one at 535 ?C and the other at 670 ?C, which are related to crystallization of the ?-Fe(Si) and the boride
phases, respectively. The crystallization activation energy is evaluated by using two models, the Kissinger
model and the Johnson-Mehl-Avrami (JMA) model, which are consistent with each other. Ultrasoft
magnetic properties are obtained after proper annealing due to the formation of an appropriate volume
fraction of nanostructured ?-Fe(Si) embedded in a residual amorphous matrix to compensate the total
magnetostriction. The influence of the annealing process on the soft magnetic properties of the studied
sample was investigated and is discussed.
