Studies of Physical Adsorption

成立了一个新的材料研究小组，研究物理吸附膜的物理吸附和相变的基本方面。本研究的目的是研究物理吸附膜的结构和动力学，以及这些相的性质和它们之间的转变。研究分为五个主题：(1)石墨上单层氩膜的熔化，(2)二元吸附剂膜的相变，(3)分子筛多孔介质中简单气体的性质，(4)弱结合衬底上单层和多层氦膜的特殊性质，(5)薄膜的解吸和氦原子散射。实验工作包括热容量测量、原位蒸汽压等温线研究、非弹性氦散射、高分辨率低能电子衍射、非弹性氦散射、中子散射、飞行时间解吸测量以及润湿和超流体研究。分子动力学计算机模拟被用于提供薄膜和受限流体的吸附行为和相变的真实模型。相互作用势，原子表面散射，以及吸附质系统的经典和量子跃迁正在使用势能模型和统计力学方法在该计划的理论推力中进行研究。实验、计算模拟和理论的强耦合使孤立的方法无法取得进展。

A new Materials research Group is established to investigate fundamental aspects of physical adsorption and phase transitions in physisorbed films. The goals of the research are to study both the structure and kinetics of physisorbed films, and the nature of these phases and the transitions between them. The research is organized into five topics: (1) melting of monolayer argon films on graphite, (2) phase transitions of films of binary adsorbates, (3) properties of simple gases in a well- characterized zeolite porous medium, (4) unusual properties of monolayer and multilayer helium films on weak-binding substrates, (5) desorption and helium atom scattering of films. Experimental efforts include measurement of heat capacity, in-situ vapor pressure isotherm study, inelastic helium scattering, high- resolution low-energy electron diffraction, inelastic helium scattering, neutron scattering, time-of-flight desorption measurements, and wetting and superfluid studies. Molecular dynamics computer simulation is being used to provide realistic modelling of adsorbate behavior and phase transitions of thin films and confined fluids. Interaction potentials, atom-surface scattering, and classical and quantum transitions of adsorbate systems are being studied in the theoretical thrusts of the program using potential energy models and statistical mechanics approaches. The strong coupling of experiment, computational simulation and theory are making advances not possible by isolated approaches.