Applications of image processing techniques to the structural characterization of small metallic particles

Abstract

Digital image processing techniques have become one of the main tools on image characterization in transmission electron microscopy. Applications of these techniques in the field of small metallic particles are widely known. The results presented in this communication explore some of the structural characteristics of decahedral gold particles. The work is based on HREM images of these type of particles obtained along five-fold axis.Small gold particles have been prepared by evaporation onto a vacuum cleaved NaCl surface. Lattice resolution images and microdiffraction patterns from individual particles have been obtained. Some of the images have been digitized with a scanning microdensitometer and computer processed.Fig. 1 shows a HREM image of a decahedral gold particle obtained under diffraction conditions close to a five-fold zone axis. This image has been digitized and a computed “microdiffraction” pattern has been obtained from each of the five segments.