Metal Surfaces, Quantum Wells, and Superlattices

研究了纳米晶的结构、生长行为和性质， 选择的金属表面，界面，覆盖层，量子威尔斯， 多层膜和超晶格。 目的是 对科学原理有基本的了解 控制着晶体的形态，化学成分， 金属外延系统的电子性质和量子 结构. 所采用的实验技术包括 （角分辨）同步光电发射，俄歇光谱， 电子衍射，扫描隧道显微镜和 光谱学和掠入射X射线衍射。 样品 将使用标准的真空制备和制造 技术以及分子束外延和查米卡尔蒸汽 证词 这项工作将包括调查散装和 表面能带结构、相干性和散射长度，以及 电子态的空间分布;吸附几何学， 团簇和岛的形成，薄膜生长行为;演化 表面，界面和量子阱状态的函数， 样品结构;掩埋界面原子结构;耦合 以及与超晶格有关的现象 和多层结构。 %%% 由薄层堆叠而成的人造结构可以表现出 有趣和潜在有用的电子性质。 使用 最先进的材料合成技术， 可以制造具有层厚度的层配置 接近原子尺度。 在这样的系统中，电子可以 被夹在中间的波纹困住、反射或折射 层次。 因为这些发生在原子尺度上， 电子性质的改变可以通过以下方式实现： 调整结构。 该研究项目将采用 各种实验技术来解决基本问题 关于各种层的生长和表征 以及原子结构之间的关系 和电子性质。 部分工作将由 在威斯康星州的麦迪逊的同步辐射中心 布鲁克海文国家同步加速器光源 国家实验室。 这项研究涉及以下方面的合作： 这项工作得到了美国国家科学基金会和 能源部。

A study of the structure, growth behavior; and properties of selected metal surface, interfaces, overlayers, quantum wells, multilayers, and superlattices is proposed. 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 to be employed include (angle-resolved) synchrotron photoemission, Auger spectroscopy, electron diffraction, scanning tunneling microscopy and spectroscopy, and grazing-incidence X-ray diffraction. Samples will be prepared and fabricated using standard ultrahigh vacuum techniques as well as molecular beam epitaxy and chamical vapor deposition. The work will include investigation of bulk and surface band structure, coherence and scattering lengths, and spatial distributions of electronic states; adsorption geometry, cluster and island formation, and film growth behavior; evolution of surface, interface, and quantum-well states as a function of sample structure; atomic structure of buried interfaces; coupling between quantum wells; and phenomena pertaining to superlattices and multilayer structures. %%% Artificial structures made of stacks of thin layers can exhibit interesting and potentially useful electronic properties. Using state-of-the-art techniques for materials synthesis, it is now possible to fabricate layer configurations with layer thicknesses approaching the atomic dimension. In such systems, electrons can become trapped, reflected, or refracted by the boudaries between layers. Because these happen on an atomic scale, substantial modifications of the electronic properties can be achieved by tailoring the structure. This research project will employ a variety of experimental techniques to address the basic questions concerning the growth and characterization of various layer configurations, and the relationships between the atomic structure and the electronic properties. Part of the work will be carried out at the Synchrotron Radiation Center at Madison, Wisconsin and the National Synchrotron Light Source at the Brookhaven National Laboratory. This research involves a cooperation between work supported by the National Science Foundation and the Department of Energy.