Evidence for a magnetic contribution to the electrical resistivity in amorphous Fe₈₀B_20-xC_x alloys

Abstract

The electrical resistivity ρ as a function of temperature has been measured for amorphous Fe₈₀B_20-xC_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 ρ_str, there exists a significant magnetic contribution ρ_mag to ρ in such glasses. The values of ρ_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 Θ_D, the structure factor S₀(2k_F), and 2k_F from ρ _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.