Structural Studies of Small Particles and Surfaces

9529453首席研究人员过去的研究表明，生长在硅表面的银小颗粒不是单晶，而是各种不同的形态，包括多孪晶颗粒。这个项目更详细地研究了在超高真空条件下在硅和锗表面生长的小颗粒的结构。在1-20 nm的尺寸范围内研究了这些粒子的内部结构和表面结构。主要的实验技术是超高真空条件下的高分辨率电子显微镜与更传统的表面科学探针相结合。一个需要探索的问题是在统计意义上出现在混合形态生长系统中的粒子类型。小颗粒在许多重要的技术过程中发挥着重要的作用，例如多相催化、许多薄膜系统的初始生长，以及最近在纳米材料和量子点领域的应用。本程序研究结构和相关杂质效应的各个方面。***

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. ***