Evidence for a magnetic contribution to the electrical resistivity in amorphous ${\mathrm{Fe}}_{80}$${\mathrm{B}}_{20\mathrm{-}\mathrm{x}}$${\mathrm{C}}_{\mathrm{x}}$ alloys

The electrical resistivity ρ as a function of temperature has been measured for amorphous ${\mathrm{Fe}}_{80}$ ${\mathrm{B}}_{20\mathrm{-}\mathrm{x}}$ ${\mathrm{C}}_{\mathrm{x}}$ (0≤x≤10) alloys in the temperature range 4.2–300 K. A detailed quantitative analysis of the resistivity data for the first time establishes that besides a dominant structural contribution ${\rho }_{\mathrm{str}}$, there exists a significant magnetic contribution ${\rho }_{\mathrm{mag}}$ to ρ in such glasses. The values of ${\rho }_{\mathrm{mag}}$ for the investigated glassy alloys reveal that the quenched disorder does not exert any noticeable influence on the coherent scattering of electrons from long-wavelength magnons and that the net contribution to ρ due to the elastic and incoherent components of electron-magnon scattering is negligibly small. Furthermore, the present data analysis permits a straightforward calculation of the Debye temperature ${\Theta }_D$, the structure factor $S_0$(2$k_F$), and 2$k_F$ from ${\rho }_{\mathrm{str}}$; and the values of these quantities so determined, in turn, bring to the limelight various limitations of the extended Ziman theory so far as its application to glasses containing a strong scattering transition metal (e.g., Fe in the present case) is concerned.