Boundary diffusion of 99Mo in annealed Fe76Mo8Cu1B15, Fe40Ni40B20 and Fe80B20 alloys

Diffusion characteristics of 99Mo in three amorphous alloys were measured using a serial sectioning method combined with Ar+ ion beam sputtering technique. The study was carried out in the temperature interval 548–648 K. It was found that diffusion is controlled by two diffusion mechanisms and that the faster one is sensitive to thermal pre-treatment of the alloy. It was concluded that the slower diffusion mechanism is due to volume diffusion in the rest of the amorphous phase, the faster one can be ascribed to diffusion in interface between the crystallites and the rest of the amorphous phase.