2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27593The surface free energies, interfacial tensions and correlation lengths of the Andrews-Baxter-Forrester models in regimes III and IV are calculated with fixed boundary conditions. The interfacial tensions are calculated between arbitrary phases and are shown to be additive. The associated critical exponents are given by $2-α_s=μ=ν$ with $ν=(L+1)/4$ in regime III and $4-2α_s=μ=ν$ with $ν=(L+1)/2$ in regime IV. Our results are obtained using general commuting transfer matrix and inversion relation methods that may be applied to other solvable lattice models.21 pages, LaTeX 2e, requires the amsmath packageCondensed Mattertext