Studies of Weakly Adsorbed Layers

该项目是一项合作研究，采用实验和理论方法研究表面作用力及其对薄膜结构和动力学的影响的基本问题。需要解决的关键问题包括何时以及为什么许多吸附系统显示出低配位的吸附位置，以及现有理论是否足以描述简单气体的超弱吸附。这些研究将扩展该小组之前的研究，为理解弱吸附现象奠定了部分经验和理论基础。将采用的技术包括低能电子衍射、氦原子散射、计算机模拟和最新的理论方法。这些研究的重要性在于，它们将提供对吸附现象的基本了解，这些现象将适用于许多不同的领域，包括纳米图案化、自组装单分子膜、涂层技术、摩擦学和芯片制造。学生和博士后学者将接受适用于上述技术的基本方法的培训。表面科学作为一门对许多技术具有基本兴趣和潜在应用的学科具有重要意义。这个项目解决了这一领域的一些基本科学问题。将探索的主要问题包括只有一个分子厚的薄膜的结构。这项研究的一个重点是确定单个分子相对于下面的支撑面的位置。第二个主要话题是这些薄膜与表面的结合有多强以及它们的动力学。在某些情况下，这样的薄膜在高温下会结合到表面上，但在低温下不会。在其他情况下，观察到的情况正好相反。这些现象以及其他许多现象将用不同的实验、理论和计算方法来探索。主要的实验技术是电子束和原子束的表面散射。将使用最先进的建模方法进行理论和仿真，其中一些方法将作为研究的一部分得到进一步改进。这项研究将从所应用的技术组合中受益。学生将接受适用于工业企业的基本方法的培训，如涂层、润滑剂和计算机芯片的开发和制造。

This project is a collaborative study employing both experimental and theoretical methods to study fundamental questions about forces at surfaces and their implications for the structure and dynamics of thin films. Key problems to be addressed include when and why many adsorption systems exhibit low-coordination adsorption sites, and whether the existing theory adequately describes the ultra-weak adsorption of simple gases. These studies will extend the groups' previous research, which has established a partial empirical and theoretical base for understanding weak adsorption phenomena. The techniques to be employed are low-energy electron diffraction, He-atom scattering, computer simulations and state-of-the-art theoretical methods. The importance of these studies is that they will provide a fundamental understanding of adsorption phenomena that will be applicable to many different fields, including nano-patterning, self-assembled monolayers, coatings technology, tribology and chip fabrication. Students and postdoctoral scholars will be trained in fundamental methods, which are applicable to the aforementioned technologies.Surface science is of importance as a subject of both fundamental interest and potential application to many technologies. This project addresses a number of basic scientific questions in this area. Principal problems that will be explored include the structure of films that are just one molecule thick. A focus of this research is the determination of where individual molecules sit in relation to the underlying supporting surface. A second major topic is the question of how strongly these films are bound to the surface as well as their dynamics. In some cases, such films are bound to the surface at high temperature, but not at low temperature. In other cases, the reverse situation is observed to be the case. These phenomena, and many others, will be explored with diverse experimental, theoretical and computational methods. The principal experimental techniques are electron and atom beam scattering from surfaces. Theory and simulation are to be carried out, using state-of-the-art modeling methods, some of which will be further improved as part of the research. The research will benefit from the combination of techniques being applied. Students will be trained in fundamental methods which are applicable to industrial concerns such as the development and fabrication of coatings, lubricants, and computer chips.