Temperature dependence of the resistivity of amorphous Fe-Co-Zr alloys

The electronic contribution to the resistivity, rho, and its temperature dependence were investigated for amorphous FexCo1-xZr2 (0 less than or equal to x less than or equal to 1) alloys in the temperature range 80-300 K. As Fe-rich compositions may exhibit spin-fluctuation effects, transport properties were not studied at temperatures <80 K where these effects must be taken into consideration. The compositional and structural integrity of the samples was verified by means of X-ray diffractometry, electron-microprobe analysis and differential scanning calorimetry. It was observed that rho(T) for these glasses which contain a number of d electrons at the Fermi energy level, E-F, had a temperature dependence of the form: A + B exp(-T/Delta). The characteristic temperature, Delta, was found to be related to the Debye temperature, theta(D), and the parameter B to be consistent with the electronic specific heat coefficient, gamma. The glasses had negative temperature coefficients of the resistivity, alpha, which increased as the iron content increased. (C) 1999 Elsevier Science B.V. All rights reserved.