PHYSICAL REVIEW E, cilt.105, sa.5, 2022 (SCI-Expanded)
We study the question of universality in the two-dimensional spin-1 Baxter-Wu model in the presence of a crystal field A. We employ extensive numerical simulations of two types, providing us with complementary results: Wang-Landau sampling at fixed values of A and a parallelized variant of the multicanonical approach performed at constant temperature T. A detailed finite-size scaling analysis in the regime of second-order phase transitions in the (A, T ) phase diagram indicates that the transition belongs to the universality class of the four-state Potts model. Previous controversies with respect to the nature of the transition are discussed and attributed to the presence of strong finite-size effects, especially as one approaches the pentacritical point of the model.