The freezing transition of monolayer xenon on single crystal graphite

We have observed the melting of monolayer xenon on a single crystal graphite surface at T = 134 K. Surface imperfections and the small scattering power of a single layer of atoms limit the observable range of fluid correlations to 2000 and 200 Å respectively; the evolution is continuous over 0.4 K. The transverse peak width is four times the longitudinal in the fluid phase. We note that this value is anomalously small for an isotropic fluid but consistent with a hexatic phase. This peak anisotropy remains in the solid phase, as in a quenched hexatic. A full account of these results may be found elsewhere [1]. © 1985.