Hamiltonian of the phase separation border and phase transitions of the first kind. II. The simplest disordered phases

Cluster expansion of the Hamiltonian of the phase separating boundary is introduced and the conditions on this expansion are found which guarantee the validity of the results obtained in the first part of this paper. The results are applied to manycomponent models with the block structure of the matrix of nearest neighbours interaction and also to non-finite perturbations of such models, to perturbations of the Potts model at large $N$ and to one of the models of the “gas – rigid crystal” type.