Diffusion coefficients of Pb in AgPb determined by surface segregation studies

Abstract

Due to experimental issues, atomic transport kinetics in nanostructures is still rarely quantitatively investigated despite its significant importance for the design of nanostructure fabrication processes and the prediction of nanoobject structure and physical property ageing. Atomic diffusion in nanostructures is expected to be mainly mediated via atomic transport in interfaces. However, in order to fully understand atomic transport in nanostructures, it is necessary to develop experimental methods allowing for the measurement of diffusion coefficients in nanovolumes, in interfaces, and in interface intersections. To date, this type of measurement has been essentially performed in nanocrystalline materials, giving access to diffusion measurements in nanocrystals corresponding to the nanograins, in grain boundaries corresponding to the interfaces between disoriented crystals of same nature, and in triple junctions corresponding to the grain boundary intersections. This chapter presents the current methods and techniques reported in the literature that have been used for such a type of measurement. Some of the original observations concerning atomic transport in nanocrystalline materials are also presented and discussed.