Electrical Resistance and Crystallization Characteristics of Fe/Sub 80/B/Sub 20/a

Abstract

The electrical resistance of amorphous Fe80B20 has been measured as a function of time at various temperatures during an isothermal crystallization process. The results fit a universal curve when ∆R/∆R1 is plotted against t/t1. The value of t, as a function of annealing temperature fits the Johnson-Mehl-Avra:ni equation with n = 3 changing to 1.4 for t/t1 > 1.4. The resistance of a series of partially crystallized samples was measured between 4.2 and 300 K. dR/dT at 300 K and dR/dlogT below the resistance minimum were both found to be linear funtions of ∆R/∆R1. That is, both the above quantities were found to be strictly proportional to the amount of crystalline phase present. This may pose some difficulty for the structural tunneling model of the low temperature resistance minimum in metallic glasses.