Surface Crystallography by Low-Energy Ion Scattering

本研究的目的是利用低能离子散射(LEIS)和扫描隧道显微镜(STM)技术来确定各种薄膜电子材料的表面结构。要研究的系统包括：银(001)表面的铁磁性铁和镍的单层薄膜，硅(111)表面的铜-氯异质外延薄膜，金原子与镓-砷(110)的化学相互作用，以及金催化的硅表面的氧化。这两项互补的技术将被用来构建这些系统及其支撑的衬底的准确原子分辨率模型。提出了一种新的计算固体表面低能粒子散射角分布的数学算法。离子散射装置将进行改装，以允许对散射离子和中性粒子进行飞行时间探测。这将有助于在阿秒时间尺度上研究离子与表面之间的电荷交换机制。

The objectives of this research are to determine the structures of the surfaces of various thin-film electronic materials using the techniques of low-energy ion scattering (LEIS) and scanning tunneling microscopy (STM). Systems to be studied include: monolayer films of ferromagnetic iron and nickel on silver(001) surfaces, thin heteroepitaxial films of copper-chlorine on silicon(111), the chemical interaction of gold atoms with gallium-arsenic(110), and the gold-catalyzed oxidation of silicon surfaces. The two complementary techniques will be employed to construct accurate atomic resolution models of these systems and the substrates on which they are supported. A new mathematical algorithm will be developed for calculating the angular distributions of low-energy particles scattered from solid surfaces. The ion scattering apparatus will be modified to permit time-of-flight detection of scattered ions and neutrals. This will facilitate study of charge exchange mechanisms on an attosecond time scale between ions and surfaces.