Abstract

The molecular properties of water at surfaces have wide importance and, in recent years, surface scientists have used single crystal studies to investigate the structure and self-organisation in thin ice films. Experiments are difficult because the films are easily damaged by conventional probes such as X-rays and electrons, and also because those probes are relatively insensitive to the protons in the water. It remains an important yet challenging topic in surface science. In this talk I will survey some recent advances in the field, mainly with respect to structure at surfaces and the degree of the order than exists. I will also present some helium atom diffraction studies. In some respects helium atoms are an ideal structural probe for water and ice films since there is negligible damage to the surface and the Helium atom is sensitive to the hydrogen atoms in the water. However, the ice is complicated and highly corrugated, hence it is not safe to ignore multiple scattering The talk concludes with a discussion of the possibility of using exact, multiple scattering calculations to model the experiment. I will show how they may be used to study the degree of proton ordering in ice Ih surface.