Metallic and Magnetic Quantum Structures

研究了金属表面、界面、量子阱和超晶格的结构、生长行为和性能。目的是获得对控制金属外延系统和量子结构的晶体形式，化学成分和电子特性的科学原理的基本理解。实验技术包括角度分辨同步加速器光电发射、俄歇光谱、电子衍射和扫描隧道显微镜。这项工作将包括研究(1)体和表面带结构、相干和散射长度以及电子态的空间分布；(2)薄膜生长的物理和化学；(3)各种量子构型的结构-性质关系；(4)二维表面合金中的近藤效应；(5)含磁性材料系统中的自旋效应。由薄层堆叠而成的人工结构可以表现出有趣的和潜在有用的电子特性。利用最先进的材料合成技术，现在可以制造具有原子层精度的层构型。这种系统中的电子可以被层之间的边界捕获、反射或折射，从而产生新的特性，为各种电子应用提供了机会。本研究计划将采用多种实验技术，研究原子层形成的基本物理和化学，并确定原子结构与电子性质之间的关系。部分工作将在同步辐射中心进行，这是一个由国家科学基金会资助的国家设施。＊＊＊

w:\awards\awards96\*.doc 9531809 Chiang The structure, growth behaviors, and properties of selected metal surfaces, interfaces, quantum wells, and superlattices are being investigated. The purpose is to obtain a fundamental understanding of the scientific principles that govern the crystalline form, chemical composition, and electronic properties of metal epitaxial systems and quantum structures. The experimental techniques include angle-resolved synchrotron photoemission, Auger spectroscopy, electron diffraction, and scanning tunneling microscopy. The work will include investigations of (1) the bulk and surface band structure, coherence and scattering lengths, and spatial distributions of electronic states, (2) the physics and chemistry of film growth, (3) the structure-property relationships for various quantum configurations, (4) Kondo effects in two dimensional surface alloys, and (5) spin effects in systems containing magnetic materials. %%% Artificial structures made of stacks of thin layers can exhibit interesting and potentially useful electronic properties. Using state-of-the-art techniques of materials synthesis, it is now possible to fabricate layer configurations with atomic layer precision. Electrons in such systems can become trapped, reflected, or refracted by the boundaries between layers, resulting in new properties, which offer opportunities for various electronic applications. This research project will employ a variety of experimental techniques to investigate the basic physics and chemistry of atomic layer formation, and to determine the relationships between the atomic structure and the electronic properties. Part of the work will be carried out at the Synchrotron Radiation Center, a national facility funded by the National Science Foundation. ***