EXAFS studies on nanocrystalline tungsten

Abstract

Abstract Nanocrystalline materials are polycrystals with typical diameters of the crystallites in the order of 5 to 15 nm, so that about 30 vol.% of the material consists of grain boundaries. EXAFS studies indicate a disordered atomic arrangement in this grain boundary component. An enhanced intensity reduction of the EXAFS oscillations of nanocrystalline Was compared with nanocrystalline Cu suggests the atomic structure of the grain boundaries in nanocrystalline b.c.c. metals differs structurally from those in nanocrystalline f.c.c. metals.