Monte Carlo Simulation of an Antiferromagnetic Disordered Blume–Capel Model

The Blume–Capel model provides a framework for studying tricritical behavior and first- and second-order phase transitions in spin systems where vacancies are allowed. In this project, we investigate an antiferromagnetic Blume–Capel model on a triangular lattice, in which disorder is introduced through a gaussian random crystal field. We aim to understand how antiferromagnetic coupling influences thermodynamic observables and the nature of the phase transitions. We perform Markov Chain Monte Carlo simulations and compute the sublattice resolved magnetization, energy, magnetic susceptibility, specific heat, and the Edwards–Anderson order parameter as functions of temperature and disorder strength. By varying the degree of disorder, we study how this affects the phase diagram and the critical behavior in the vicinity of the phase transition.