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The morphology of supported Bi particles is studied using the technique of profile imaging at atomic resolution. These particles show a crystallized Bi core surrounded by an amorphous (or liquid) material. For small supported particles (diameter of the Bi core, about 6-9 nm) observed by high-resolution electron microscopy at room temperature, the lattice fringe orientation changes very rapidly during the observation. This fluctuating evolution is attributed to atomic rearrangements of the particle induced by the microscope electron beam. During this evolution, a decrease in the size of the crystallized Bi core is sometimes observed for the smaller particles.

Small bismuth clusters with a narrow size distribution (two to ten atoms) were produced by the inert-gas condensation technique and deposited at room temperature on an amorphous carbon film. We have shown that the growth process involves the formation of large particles (diameter from 1·5 to 20 nm). The larger particles have been characterized by high-resolution transmission electron microscopy. These particles are formed with a single-crystal core edged by an amorphous shell. Cluster images in the [2201], [0001] and [0110] directions are presented and compared with simulated images of bismuth single crystal.