Simple Atoms on Metal Surfaces

本研究项目涉及金属表面碱金属原子和稀有气体原子的低能电子衍射（LEED）和氦原子散射（HAS）实验，以及分子动力学模拟。目标是增加我们对表面原子平衡结构的相互作用和性质的理解。方法是利用动态LEED确定相应结构的结构、振动幅值及其温度依赖关系。缺陷（如台阶）对这些覆盖层的影响也将被研究，新的LEED计算技术将为这些系统开发。此外，将进行研究，以了解波纹在不相称层的旋转外延中的作用。这个研究项目涉及研究简单原子如钾或氙吸附在金属表面如银或铜上所形成的结构。它们的结构可以通过电子或氦原子的衍射来确定。当简单原子被吸附在表面上时，形成的结构可能与它们被吸附的表面具有相同的周期性，也可能具有不同的周期性。通过测量这种周期性，我们获得了这些原子如何与表面相互作用的信息。这种吸附原子的基本相互作用是有趣而有用的，其原因多种多样，从学习如何制造更好的计算机芯片到发明一种测量表面张力的仪器。＊＊＊

w:\awards\awards96\*.doc 9629715 Diehl This research program involves low energy electron diffraction (LEED) and helium atom scattering (HAS) experiments, as well as molecular dynamics simulations, of alkali metal atoms and rare gas atoms on metal surfaces. The goal is to increase our understanding of the interactions and properties which give rise to the equilibrium structures of atoms at surfaces. The approach is to determine the structures, the vibrational amplitudes and their temperature dependence in commensurate structures using dynamical LEED. The effects of defects such as steps on these overlayers will also be investigated, and new LEED calculational techniques will be developed for these systems. Additionally, studies will be made in order to understand the role of corrugation in the rotational epitaxy of incommensurate layers . %%% This research program involves the study of the structures which form when simple atoms such as potassium or xenon are adsorbed on metal surfaces such as silver or copper. Their structures will be determined by using the diffraction of electrons or helium atoms. When simple atoms are adsorbed on surfaces, the structures which form may have the same periodicity as the surface on which they are adsorbed, or a different periodicity. By measuring this periodicity, we obtain information on how these atoms interact with the surface. Such fundamental interactions of adsorbed atoms are interesting and useful for reasons as diverse as learning how to build better computer chips to inventing an instrument to measure surface tension. ***