AN ANOMALY IN THE TEMPERATURE-DEPENDENCE OF THE RESISTIVITY OF AMORPHOUS METALLIC FEXGE1-X ALLOYS AT LOW-TEMPERATURES

The anomalous decrease in the resistivity observed in the amorphous CrxSi1-x, CrxGe1-x, and FexGe1-x systems as T decreases below about 30 K, and the subsequent increase in the resistivity as the temperature decreases below about 4 K are investigated in amorphous FexGe1-x films of nominal thickness 500 Angstrom and 2000 Angstrom for 0.189 less than or equal to x less than or equal to 0.297. In this first detailed study the results of both resistivity and magnetoresistance measurements (0.1 less than or equal to T less than or equal to 6 K and 0 less than or equal to B less than or equal to 4 T; 5 less than or equal to T less than or equal to 100 K and 0 less than or equal to B less than or equal to 8.5 T) are reported, and interpreted in terms of electron-electron interactions, weak localization, and spin fluctuations.