The correlation between structural relaxation process and the change in magnetic permeability of the Fe73.5Cu1Nb3Si15.5B7 amorphous alloy under the thermal influence

Abstract

Fast cooling of 106 K/s, according to the melt-spinning method, led to the Fe73.5Cu1Nb3Si15.5B7 amorphous alloy formation. X-ray diffraction analysis method (XRD) showed that the obtained alloy is in amorphous state. The differential scanning calorimetry method (DSC) has defined the temperature interval of the crystallization process to be from 510ºC to 540ºC. The same temperature interval has also been confirmed by measuring electrical resistivity dependence over temperature. The heating of alloy sample in the temperature interval from 25ºC to 600ºC, leads to structural changes in the alloy under the thermal influence. Structural relaxation and crystallization processes have been investigated by thermoelectromotive force measurement (TEMF) of thermocouple amorphous alloy - copper. Based on the change in temperature coefficient of TEMF thermocouple annealed at various temperatures, relative changes in electron state density near Fermi level have been determined. It has been shown that the changes in normalized magnetic permeability in correlation with appropriate structural changes, which cause changes in electron state density near Fermi level.

Keywords

• thermoelectromotive force
• electron state density near Fermi level
• electrical resistivity
• magnetic permeability