Monolayer Physics

这是一个低温物理项目，研究氦在固体表面的吸附。用热力学和中子散射技术研究了吸附在固体表面的薄膜中的准二维物质的各种相。3He和4He的液体混合物在0.2K以下测量以寻找二维相分离，而D2-Ne的固体混合物在2K到20K之间被测量以寻找和研究混合、凝固和二维共晶点。开发了新的吸附表面来探索二维氢的凝固点的变化，这可能导致新的超流体。含氢固体薄膜和/或含氢液体薄膜上的中子散射测量补充了热力学测量，得到了固体的结构和液体的流动性。相对较厚的均匀薄膜的快速冻结探索了控制液体过冷的参数。这个低温物理项目研究气体、液体和固体薄膜，这些薄膜由原子和/或分子润湿固体表面形成，厚度为一到几个原子或分子层。测量结果提供了关于原子迁移率、不同组分的混合和分解、制造新的表面以产生可移动薄膜、某些流体对表面的润湿以及纯和混合液膜中的过冷的信息。热力学测量是由华盛顿大学的研究生和本科生通过内部设计和建造的实验进行的，而中子散射测量是在萨克莱和格勒诺布尔与外国科学家合作进行的。研究生参加国际实验。这项工作培训学生在制冷、现代数据采集方法、高真空技术、非常小样本的测量(纳米技术)和表面分析工具方面。***

9876763VilchesThis is a low temperature physics project dealing with helium adsorbed on solid surfaces. Various phases of quasi two-dimensional (2-d) matter, as occurring in films adsorbed on solid surfaces, are studied with thermodynamic and neutron scattering techniques. Liquid mixtures of 3He and 4He are measured below 0.2K to search for 2-d phase separation, and solid mixtures of D2-Ne are investigated between 2K and 20K to search for and study mixing, solidification, and 2-d eutectic points. New adsorbing surfaces are developed to explore changes in the freezing point of 2-d H2 which may lead to a new superfluid. Neutron scattering measurements on solid films containing deuterium and/or liquid films with deuterium hydride complement the thermodynamic measurements yielding the structure of solids and the mobility of liquids. The fast freezing of relatively thick uniform films explores the parameters which control the supercooling of liquids.%%%This low temperature physics project studies gaseous, liquid, and solid films, one to a few atomic or molecular layers thick, formed by atoms and/or molecules which wet solid surfaces. Results of measurements yield information on atomic mobilities, mixing and unmixing of different components, fabrication of new surfaces to produce mobile films, wetting of surfaces by certain fluids, and supercooling in pure and mixture liquid films. Thermodynamic measurements are carried out by graduate and undergraduate students at the University of Washington with experiments designed and built in house, while neutron scattering measurements are done at Saclay and Grenoble in collaboration with foreign scientists. Graduate students participate in the international experiments. This work trains students in refrigeration, modern data acquisition methods, high vacuum technology, measurements on very small samples (nanotechnology), and surface analysis tools. ***