Production and Electron Diffraction Studies of Silver Metal Clusters in the Gas Phase

摘要

Silver is evaporated into an inert gas flowing at pressures between 0.1 and 3 torr and nucleates to form clusters in a size range of 40 to 110 A. This two-phase mixture flows through a two stage molecular beam into a modified electron microscope. Electron diffraction patterns are taken in the cluster beam and analyzed assuming the bulk, face centered cubic unit cell and using a thirteen-beam, multislice, multiple scattering program. Deviations from the bulk structure are seen and are larger for smaller cluster size. Several possible interpretations are discussed. The use of inert molecular gasses as carriers is found to greatly increase cluster production.