CONTINUOUS WETTING TRANSITIONS IN ADSORBED XE FILMS

A continuous wetting transition, long observed in model calculations b ut yet to be found experimentally, is predicted for Xe adsorbed on NaF as well as for Xe adsorbed on Cs and Rb substrates plated with one or more layers of a variety of other materials, including gold, copper, and MgO. The analysis is based on the Dzyaloshinskii-Lifshitz-Pitaevsk ii dielectric formalism together with the simple, but accurate, scheme for calculating surface tension differences introduced for the helium on cesium problem. Critical exponents are given, and the crossover fr om first order to continuous wetting as a function of plating material thickness is discussed.