The isotope effect for Co diffusion in CoxZr1-x glasses, where x ranged from 0.31 to 0.86, was measured by using a radiotracer technique. It was found that the isotope effect was close to zero (table 7) over 3 orders of magnitude of the diffusivity (figure 4), in spite of the existence of large activation volumes. The results strongly suggested that a highly collective diffusion mechanism was a widespread phenomenon in metallic glasses, and diffusion via delocalized thermal effects was expected to occur at certain compositions.

Evidence of Highly Collective Co Diffusion in the Whole Stability Range of Co-Zr Glasses. A.Heesemann, V.Zöllmer, K.Rätzke, F.Faupel: Physical Review Letters, 2000, 84[7], 1467-70

Figure 4

Diffusivity of Co in CoxZr1-x

Table 7

Isotope Effect in CoxZr1-x