DISLOCATIONS, GRAIN-SIZE AND PLANAR FAULTS IN NANOSTRUCTURED COPPER DETERMINED BY HIGH-RESOLUTION X-RAY-DIFFRACTION AND A NEW PROCEDURE OF PEAK PROFILE ANALYSIS

The particle size and the dislocation structure in inert gas condensed nanocrystalline copper were determined by high-resolution X-ray diffr action profile analysis. Well-behaved smooth curves were obtained in t he modified Williamson-Hall plot and the modified Warren-Averbach plot through knowledge of the variation in dislocation contrast with Bragg reflection and the effect of twinning on particle size. The particle size was between 14 and 30 nm, in agreement with TEM results. The root -mean-squared strains were explained by the presence of dislocations, with a dislocation density of about 5 x 10(15) m(-2). The dislocations were found to have screw character probably related to the particle g rowth mechanism. (C) 1998 Acta Metallurgica Inc.