The Ordered Structures Formed by Janus-like Particles on a Triangular Lattice.

Abstract

The formation of ordered structures by Janus-like particles, composed of two parts (A and B), with orientation-dependent interactions on a triangular lattice was studied using Monte Carlo methods. The assumed lattice model allows each particle to take on one of the six orientations. The interaction between the A parts of neighboring particles was assumed to be attractive, while the AB and BB interactions were assumed to be repulsive. Moreover, it was assumed that the interaction between a pair of neighboring particles depended on the degrees to which their AA, AB, and BB parts face each other. It was shown that several ordered phases of different densities and structures may appear, depending on the magnitudes of AB and BB interactions. In particular, we found several structures composed of small clusters consisting of three (OT), four (OR), and seven (S) particles, surrounded by empty sites, the lamellar phases (OL, OL1, and OL3), the structures with hexagonal symmetry (R3×3 and K), as well as the structures with more complex symmetry (R5×5 and LAD). Several phase diagrams were evaluated, which demonstrated that the stability regions of different ordered phases are primarily determined by the strengths of repulsive AB and BB interactions.