Abstract
We obtain the low-temperature phases and phase transitions of the coadsorption of two monomer species on a semi-infinite square lattice of odd width M, with first- and second-neighbor interactions. We study the cases for which first-neighbor interactions between two monomers of the same species are repulsive, allowing all other interactions to be attractive or repulsive. Most of the numerical results are found to fit exact closed-form expressions in M, thus allowing exact analytic extrapolations to the infinite two-dimensional case (M=∞).