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 75) over 3 orders of magnitude of the diffusivity (figure 13), 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.

A.Heesemann, V.Zöllmer, K.Rätzke, F.Faupel: Physical Review Letters, 2000, 84[7], 1467-70

Table 73

Diffusivity of Fe in Co79Nb14B7

 

Temperature (K)

Surface Treatment

D (m2/s)

694

polished

7.07 x 10-20

669

polished

3.82 x 10-20

669

sputtered

2.74 x 10-20

640

polished

5.77 x 10-21

640

sputtered

8.02 x 10-21

603

polished

8.41 x 10-22

603

sputtered

1.28 x 10-21

573

polished

1.28 x 10-22

573

sputtered

1.21 x 10-22

 

Figure 12

Grain-Boundary Diffusivity of Cu in Electroless Films

(Circles: Co0.9W0.02P0.08, squares: Co0.9P0.1)

 

 

Table 74

Interdiffusion in CoTi

 

Temperature (K)

D (m2/s)

1574

5.82 x 10-14

1524

3.97 x 10-14

1473

3.00 x 10-14

1424

1.51 x 10-14

1378

4.97 x 10-15

1323

9.89 x 10-16

1273

1.24 x 10-15

1221

1.62 x 10-16

1172

8.51 x 10-17