HREM CHARACTERIZATION OF GOLD-CLUSTER STRUCTURES

High-resolution electron microscope (HREM) and computer simulation are used to investigate structural features of gold clusters produced by the inert-gas condensation method. The results indicate that (i) small er clusters have multiple-twinned-like structure while those larger th an 150 Angstrom in diameter show single-crystal structure; (ii) the fo rmer cluster consists of either decahedral or icosahedral form and the atomic planes are not strictly parallel and distances between the pla nes increase towards the cluster edge; and (iii) grain boundaries betw een the clusters have twin structures with both long- and short-range orders.