After implanting the 71Ge radiotracer into Mg-1.8wt%Al alloy, tracer diffusion coefficients were measured by using both serial sectioning and residual activity techniques at 448 to 848K. Anomalously high diffusivities were observed at high temperatures, where volume diffusion usually predominated. A contribution of high-diffusivity paths to the total diffusion flux was suggested to be a possible explanation for both phenomena. A simple microstructural model was proposed, based upon the high fraction of twin boundaries which was confirmed by electron microscopy.

Anomalous Diffusion in Presence of Twin Boundaries. V.Rothová, J.Buršík: Journal of Physics and Chemistry of Solids, 2007, 68[5-6], 785-90