Diffusion of boron in nanocrystalline iron A new type of diffusion kinetics: Type C′

Abstract

Measurements of the diffusivity of boron in nanocrystalline iron are presented. It is shown that boron diffuses slower in the grain boundaries than in the lattice. The diffusion data are analysed in terms of a new type of diffusion kinetics, type C′. In type C′ kinetics, the diffuser is confined to the grain boundaries by a large segregation factor. Therefore, even though the lattice diffusion is faster than the grain-boundary diffusion, the grain-boundary diffusion coefficient is readily accessible.