Influence of structural transformations on functional properties of Fe75Ni2Si8B13C2 amorphous alloy

The influence of thermal treatment on functional properties of Fe75Ni2Si8B13C2 amorphous alloy was investigated, showing the change that resulted from thermally induced structural transformations. Thermal history of the sample was found to have a significant effect on magnetic properties. Structural transformations were identified using DSC and thermomagnetic curve and characterized using Mössbauer spectroscopy and X-ray diffraction. Further investigation of magnetic and electrical properties of the alloy showed that structural relaxation prior to crystallization affected both magnetic susceptibility and electrical resistivity of the alloy, leading to an increase in both. This was caused by a confluence of stress relieving and a decrease in number of defects and an increase in free volume in the alloy sample, not only enabling greater mobility of magnetic domain walls, but also decreasing electron density of states at the Fermi level. Annealing at temperatures below crystallization caused an increase in magnetic susceptibility of the alloy at room temperature, however, a shift in Curie temperature was not observed. The alloy also exhibits a wide supercooled liquid region before crystallization, where its functional properties remained relatively constant, exhibiting the low values of both magnetic susceptibility and electrical conductivity.