Diffusion in a Pd-Cu-Si metallic glass

Abstract
The diffusivities (D) of a Pd77.5Cu6Si16.5 glass above the glass transition agree within a factor of 3 with diffusivities (Dη) evaluated from viscosity data using the Stokes‐Einstein relationship. Below the glass transition, however, the measured D is critically related to the state of structure and can be many orders of magnitude higher than Dη. The time constant for structural relaxation is suggested to be at least three orders of magnitude longer than that for diffusion processes.