9529453 Marks Past research by the principal investigator has shown that small particles of silver grown on silicon (001) surfaces are not single crystals, but instead a variety of different morphologies including multiple-twinned particles. This project examines in more detail the structure of small particles grown on silicon and germanium surfaces under ultrahigh vacuum conditions. The structure, both internal and surface of these particles, is studied in the size range of 1-20nm. The primary experimental technique is high resolution electron microscopy under ultrahigh vacuum conditions coupled with more conventional surface science probes. A question to be explored is the type of particles in a statistical sense that occur in mixed morphology growth systems. %%% Small particles play an important role in many technologically important processes, for instance heterogeneous catalysis, the initial growth of many thin film systems, and recently in the area of nanophase materials and quantum dots. This program examines aspects of structure and related impurity effects. ***
