The pressure dependence and isotope effect of Co diffusion in metallic glasses were measured by using a radiotracer technique. Both the pressure dependence and the isotope effect were found to be very small, and were usually below the limit of detection. The results were interpreted in terms of a highly cooperative mechanism in which the mass dependence was diluted due to the participation of about 10 atoms in the elementary diffusion process. Such a mechanism did not require an activation volume for defect formation and was expected to involve a very small migration volume (in agreement with the almost zero pressure dependence).

K.Ratzke, A.Heesemann, F.Faupel: Journal of Non-Crystalline Solids, 1996, 205-207[2], 607-11