WETTING PHENOMENA AT DOMAIN BOUNDARIES.

Interfaces between the three physically distinct, but equivalent domains in the (3 multiplied by 1) phase of lattice gas models for the adsorbate systems O/Pd(110) and H/Fe(110) are studied. At the wetting transition, the interface or wall between two domains decomposes into two walls of a different type separated by a macroscopically thick region of the third domain. Using mainly Monte Carlo techniques, the characteristic walls are identified and wetting transition lines are determined for phase diagrams in the coverage-temperature plane.