Abstract
The microstructure of nanocrystalline Pd was investigated by small-angle neutron scattering. The strong scattering signal is interpreted as originating from crystallites embedded in a matrix formed by incoherent interfaces. From the scattering curves size distributions were determined, which yield an average radius of 2.6 nm. The volume fraction of the crystallites was found to be about 0.3, and the atomic density in the matrix about one-half that of Pd crystals. Structural parameters varied from sample to sample. An appreciable volume fraction of voids or interconnected channels may exist in some of the specimens.