Normal incidence X-ray standing wave analysis of thin gold films

Normal incidence X-ray standing wave (NIXSW) analysis has been successfully performed on epitaxial gold films on mica substrates using reflection from the (1 1 1) planes parallel to the surface. We show that NIXSW can be used to monitor the decrease in order within the gold film caused by annealing, and the position of sulfur within a monolayer of methyl thiolate (CH3S-) on the surface. The Au-S layer spacing was found to be 2.54 ± 0.05 Å, in close agreement with previous work on a single crystal system.