Measurements were made of the pressure and temperature dependence of 57Co diffusion in structurally relaxed metallic glass. It was found that the results (figure 2) could be described by:

D (m2/s) = 8.4 x 10-9 exp[-1.4(eV)/kT]

It was noted that the pressure dependence was extremely small, and was associated with an activation volume of about 8% of the mean atomic volume. These results ruled out the possibility that diffusion in this alloy composition was mediated by vacancy-like thermal defects; as had been suggested for Zr-rich glasses.

Activation Volume of 57Co Diffusion in Amorphous Co81Zr19 P.Klugkist, K.Rätzke, S.Rehders, P.Troche, F.Faupel: Physical Review Letters, 1998, 80[15], 3288-93