This paper reports a high-resolution synchrotron x-ray scattering study of the freezing transition as a function of temperature and chemical potential of the two-dimensional continuous-symmetry system monolayer xenon on graphite. It is found that for a coverage of 1.1 monolayers the transition is continuous to within the substrate-determined resolution with fluid correlation lengths exceeding 100 atomic spacings. Comparison is made with current theories of solidification in two dimensions.

• Received 2 November 1981

DOI:https://doi.org/10.1103/PhysRevLett.48.104