Wetting phenomena in the (3 × 1) phase of a model for H on Fe(110)

Interfaces between the three physically distinct, but equivalent domains in the (3 × 1) phase of a lattice gas model for the adsorbate system H/Fe(110) and its Ising analog are studied. In the ground state two types of wetting transitions are found where a light or a heavy domain wall decomposes into two heavy or two light walls separated by the third domain. These transitions give rise to wetting lines in the phase diagram which are located using Monte Carlo techniques.