Phase Transitions in Two-Dimensional Potts Models on the Hexagonal Lattice

Phase transitions in 2D Potts models with the number of spin states q = 4 and 5 have been studied by computer simulation. Systems with linear sizes L = 21–180 have been considered. As follows from numerical data, the 2D Potts model on the hexagonal lattice demonstrates a first-order phase transition for the number of spin states q = 5 and a second-order phase transition for q = 4.