Critical properties of antiferromagnetic Ising model on a square lattice with next-nearest-neighbor interactions

The critical properties of antiferromagnetic Ising model on a square lattice with competing nearest- and next-nearest-neighbor interactions are investigated by the replica Monte Carlo method. The static critical exponents of heat capacity, order parameter magnetization, susceptibility, correlation radius and critical Fisher exponents are calculated using the finite-size scaling theory. The analysis of the data was carried out both with the account, and without any account of the leading correction-to-scaling term. It is found that the model studied displays a second-order phase transition. A new universality class of the critical behavior is shown to be formed by the given model.