59Fe TRACER SELF-DIFFUSION IN AMORPHOUS Fe-Ni-B ALLOYS

The self-diffusion of 59Fe in the amorphous alloys Fe40Ni40B20 and Fe41Ni41B18 was investigated by means of the radiotracer technique in combination with ion-beam sputtering for serial sectioning. For the first time the influence of structural relaxations was studied in detail. It was found that during isothermal annealing in the amorphous state a relaxation-induced decrease of the diffusivity towards a value which is characteristic of the diffusion temperature takes place. This indicates the existence of a well-defined metastable amorphous state which may be attained by thermal annealing.