First-order phase transitions in lattice bilayers of Janus-like particles: Monte Carlo simulations

The first-order phase transitions in the lattice model of Janus-like particles confined in slit-like pores are studied. We assume a cubic lattice with molecules that can freely change their orientation on a lattice site. Moreover, the molecules can interact with the pore walls with orientation-dependent forces. The performed calculations are limited to the cases of bilayers. Our emphasis is on the competition between the fluid-wall and fluid-fluid interactions. The oriented structures formed in the systems in which the fluid-wall interactions acting contrary to the fluid-fluid interactions differ from those appearing in the systems with neutral walls or with walls attracting the repulsive parts of fluid molecules.Comment: 12 pages, 11 figure

Critical Binder cumulant for isotropic Ising models on square and triangular lattices

Using Monte Carlo techniques, the critical Binder cumulant U* of isotropic nearest-neighbour Ising models on square and triangular lattices is studied. For rectangular shapes, employing periodic boundary conditions, U* is found to show the same dependence on the aspect ratio for both lattice types. Similarly, applying free boundary conditions for systems with square as well as circular shapes for both lattices, the simulational findings are also consistent with the suggestion that, for isotropic Ising models with short-range interactions, U* depends on the shape and the boundary condition, but not on the lattice structure.Comment: 7 pages, 4 figures, submitted to J. Stat. Mec

Critical Binder cumulant of two-dimensional Ising models

The fourth-order cumulant of the magnetization, the Binder cumulant, is determined at the phase transition of Ising models on square and triangular lattices, using Monte Carlo techniques. Its value at criticality depends sensitively on boundary conditions, details of the clusters used in calculating the cumulant, and symmetry of the interactions or, here, lattice structure. Possibilities to identify generic critical cumulants are discussed.Comment: 6 pages, 4 figures, submitted to Eur. Phys. J.