RESISTIVITY OF AMORPHOUS FE-B ALLOYS - MEASUREMENTS AND IMPLICATIONS

Ribbons of amorphous alloys of composition Fe100-xBx (15<~x<~22) were prepared by rapid quenching from the melt. The temperature dependence of the resistivity is linear for 120T300 K and quadratic for 20T100 K; this behavior is qualitatively consistent with predictions based on recent extensions of the theory of resistivity for liquid transition metals. Within this theoretical framework, an electronic stability criterion for metallic glasses is found not to be satisfied for the Fe-B system. The experimentally determined stable composition regime (x20) agrees with predictions of random-packing models, where the boron atoms occupy voids inherent in such a structure. At the higher temperatures, the temperature coefficient of resistivity is positive and constant as a function of composition within experimental uncertainty. Based on these observations and a published structure factor for Fe84B16, it is suggested that the most probable values for the number of electrons per atom contributing to conduction are: zFe1 and 0zB1. © 1979 The American Physical Society.