SURFACE PRESSURE IN SOLID-ON-SOLID MODELS

Microscopic models of the solid-on-solid type were considered to descr ibe the surface pressure of monolayers an bilayers on top of another l ayer in two and three dimensions. The two interfaces, above and below the film, were studied in simultaneous thermal equilibrium without imp osing a fixed profile for the first fluid or solid. It is shown that t he associated mean field approximation leads to an exact determination of the surface pressure isotherms revealing the possible existence of plateaux, typical of first-order phase transitions.