Phase transitions in adsorbed layers formed on crystals of square and rectangular surface lattice
Abstract This article gives a survey of phase transitions in adsorbed films on well defined surfaces of square and rectangular symmetry of the lattice. The discussion concentrates on the effects of periodic changes of the adsorbate–substrate potential on the structure and thermodynamic properties of adsorbed films. Different theoretical approaches are briefly reviewed, with an emphasis on those which explicitly take into account final corrugation of the surface potential. Several aspects of statistical mechanical description of phase transitions in surface layers, such as order–disorder, melting, commensurate–incommensurate transitions in monolayer films as well as transitions connected wit…
Application of the Monte Carlo coherent-anomaly method to two-dimensional lattice-gas systems with further-neighbor interactions
A Monte Carlo version of the coherent-anomaly method has been used to determine critical properties of a two-dimensional Ising ferromagnet with nearest- and next-nearest-neighbor interactions and of a series of two-dimensional lattice-gas systems of particles interacting via 6-12 Lennard-Jones potential. It has demonstrated that the method leads to quite accurate determination of critical temperature but is less successful when used to determine the values of critical exponents \ensuremath{\gamma} and \ensuremath{\nu}.
Dynamics of multilayer adsorption: a Monte Carlo simulation
Abstract The growth of an adsorbed film at an initially empty surface which is exposed at time t = 0 to a gas is studied within the framework of a kinetic lattice gas model by Monte Carlo simulation. The model includes an attractive potential V ( z ) between adsorbed particles at distance z from the surface, V(z) = −A z 3 and a nearest-neighbor attractive interaction between the gas atoms. Several choices of the surface potential depth A , corresponding to different sequence of layering transitions, are considered. The Monte Carlo process assumes random evaporation/condensation events of gas atoms in adsorbed layers close to the surface, while surface diffusion is disregarded. For temperatu…
Incommensurate phases in adsorbed monolayers: structure and energy of domain walls
Abstract The properties of incommensurate films of domain-wall structure formed on the (1 0 0) plane of face centered cubic crystals are studied by Monte Carlo simulation. The wall energies, wall structure and the wall–wall interaction are determined for different types of domain walls occurring in films which form the c(2×2) registered structure. The systems characterized by different strength and corrugation of the surface potential and of different misfit between adsorbate and adsorbent are discussed. It is demonstrated that heavy as well as light walls are rather strongly localized. Moreover, it is shown that the incommensurate structure with crossing heavy walls has higher stability th…
Lattice gas models for multilayer adsorption: variation of phase diagrams with the strength of the substrate potential
Abstract The simple cubic lattice gas model with nearest-neighbor attractive interaction is considered for the case where the potential V ( z ), that an adatom at a distance z from the surface experiences due to the substrate, is V ( z ) = − A / z 3 . Exact ground state phase diagrams are obtained for different A , while the behavior at nonzero temperatures is studied both by Monte Carlo simulations and the molecular field approximation. We show that the detailed sequence of the layering transitions in the first few layers depends very strongly on the strength of the substrate potential: for strong potentials individual first-order layering transitions in layers 1, 2, 3, …, while for interm…