Phase Transitions and Critical Phenomena in the 2D Potts Impurity Model on a Square Lattice

摘要

Phase transitions and critical behavior in the 2D dilute Potts model with number q = 4 of spin states on a square lattice are investigated by computer simulation. Systems with linear sizes L x L = N, l = 10-160 with spin concentrations p = 1.00, 0.95, 0.80 are considered. It is shown that the introduction of magnetic impurities plays a stabilizing role in the realization of a second-order phase transition in the Potts model under investigation. Based on the finite-size scaling theory, statistical critical indices of heat capacity alpha, susceptibility gamma, magnetization beta, and correlation radius index nu are calculated for the range of concentrations p considered here.