Studies of Physical Adsorption

物理吸附是指分子与表面弱结合的状态（结合能小于十分之一电子伏特）。在物理吸附薄膜中观察到的许多现象引起了不同科学家群体的注意，因为它们以不同于体系统的方式揭示了物质的基本行为。这个节目提出了对当前感兴趣的一系列问题的多方面攻击。一个广泛关注的领域是电影结构；有趣的问题包括二维相的性质（相称的、不相称的、取向有序的）和这些相之间的过渡，薄膜在变成三维和湿润过渡时的生长。一个密切相关的问题涉及到这些薄膜的动力学性质。这两个问题都将通过热力学和散射技术来解决，这是在散装系统中使用的传统探针。另一个研究的基本领域是气体分子与表面的结合；这也是通过散射来研究的。伴随这些实验的将是关于同样问题的理论研究。包括应用统计力学来描述与薄膜有序相关的集体现象。计算机模拟是一种特别强大的工具，可以解释和预测这些特性，也可以测试关于力定律的理论假设。要考虑的系统包括单原子和多原子吸附物质。虽然流行的石墨衬底将得到一些关注，但氧化镁和其他衬底将得到更大的重视。用弹性和非弹性散射探针研究固体和单层薄膜的“复合”体系。

Physical adsorption refers to the state when molecules are weakly bound to surfaces (binding energies less then one-tenth of an electron volt). The many phenomena observed in physisorbed films have attracted the attention of a diverse group of scientists because they reveal fundamental behavior of matter in a different way from bulk systems. This program presents a multi-facetted attack on a set of problems of current interest. One broad area of focus is film structure; interesting questions include the nature of two dimensional phases (commensurate, incommensurate, orientationally ordered) and transitions between such phases, the growth of films as they become three dimensional and wetting transitions. A closely related problem involves the dynamical properties of these films. Both of these will be addressed by thermodynamic and scattering techniques, traditional probes used in bulk systems. Another fundamental area of investigation is the binding of gas molecules to surfaces; this also is to be studied by scattering. Accompanying these experiments will be theoretical studies concerned with the same issues. Included are the application of statistical mechanics to describe the collective phenomena associated with film ordering. Computer simulation is a particularly powerful tool to explain and predict these properties, as well as test theoretical hypotheses about the force laws. The systems to be considered include both monatomic and polyatomic adsorbate species. While the popular graphite substrate will receive some attention, magnesium oxide and other substrates will get somewhat greater emphasis. The "compound" system of solid and monolayer film will be studied by both elastic and inelastic scattering probes.