Abstract
Utilizing the radiotracers and , we have investigated the isotope effect of Co diffusion in melt-spun amorphous between 626 and 642 K. The ion-beam sputtering technique was employed for serial sectioning. For comparison, measurements were also carried out in fcc Co at 1049 K. The resulting isotope effect E≡(/-1)/[(/-1]=0.74±0.05 in polycrystalline Co is typical of diffusion via monovacancies in densely packed structures. In contrast, the extremely small value of E=0.1±0.01 obtained in amorphous allows us to rule out a defect-mediated single-atomic-jump mechanism and is consistent with a diffusion mechanism involving about ten atomic masses.
- Received 30 September 1991
DOI:https://doi.org/10.1103/PhysRevB.46.120
©1992 American Physical Society