Structure transformation and elements redistribution at heating of Fe73.5Nb3Cu1Si13.5B9 amorphous alloy

The evolution of structure and elements redistribution in rapidly quenched Finemet-type Fe73.5Nb3Cu1Si13.5B9 alloy at heat treatments were investigated by differential scanning calorimetry (DSC), thermomagnetic analysis, Moessbauer spectroscopy (MS), and X-ray diffraction methods. The effect of the structural relaxation on the Curie point of amorphous phase (TcA) has been studied using DSC and magnetic measurements. Using both heating and isothermal DSC scanning modes, we found that TcA value increases with the treatment temperature, as well as with the increase of the treatment duration. MS analysis shows that the pre-crystallization process results in the changes of fine structure of amorphous phase spectra, which are caused by the components redistribution during the relaxation process, resulting in the Cu-rich clusters formation and subsequence appearance of nanocrystals