Triple-Point Wetting of Light Molecular Gases on Au(111) Surfaces

Wetting characteristics of Ar, Kr, Xe, ${\mathrm{N}}_2$, ${\mathrm{O}}_2$, methane, and ethane adsorbed on Au(111) have been determined with a high-frequency microbalance. All gases form incompletely wet films below their bulk triple points and completely wet films above. The transitions to complete wetting are continuous, the maximum thicknesses of the layered films below $T_t$ varying as ${(T_t-T)}^{-\frac{1}{3}}$.