TEMPERATURE-DEPENDENCE OF THE ELECTRICAL-RESISTIVITY OF AMORPHOUS (FE1-XCOX)(78)SI9.5B12.5 ALLOYS

The temperature dependence of the electrical resistivity of amorphous (Fe1-xCox)(78)Si9.5B12.5 (0 less than or equal to x less than or equal to 1.0) alloys prepared by a single roller quenching apparatus was st udied. The electrical resistivity of the samples was measured by using a usual four-probe method from 4.2 to 300 K. All amorphous alloys inv estigated here are found to exhibit a resistivity minimum at low tempe rature. The temperature of resistivity minimum T-min is found first to increase and then to decrease with increasing Co content x, having a maximum value of 33.5 K at x = 0.9. The electrical resistivity exhibit s a logarithmic temperature dependence at T < T-min, and a T-2 depende nce in the interval T-min < T < 130 K. The resistivity minimum and the - ln T dependence of resistivity below T-min can be explained by the Kondo-like effect. The temperature dependence of the electrical resist ivity above T-min was discussed by the extended Ziman theory. The Deby e temperature B, calculated from the temperature coefficient of electr ical resistivity above T-min is found to be 450+/-70 K. (C) 1997 Ameri can Institute of Physics.