We have investigated the low-temperature structures of xenon overlayers on graphite with coverages ranging from 0.8 to 1.7 (√3 × √3 ) monolayers. We find that below 60 K the full monolayer has an incommensurate structure which appears to correspond to a rectangular striped phase rather than the √3 × √3 commensurate structure inferred from previous electron-diffraction studies. With increasing coverage there is a first-order transition from the monolayer striped phase to a bilayer hexagonal structure close to that of bulk xenon.

• Received 24 July 1985

DOI:https://doi.org/10.1103/PhysRevB.33.3344