Maiorano, A.Martín Mayor, VíctorRuiz Lorenzo, J. J.Tarancón, A.2023-06-202023-06-202007-08-311098-012110.1103/PhysRevB.76.064435https://hdl.handle.net/20.500.14352/52131© 2007 American Physical Society. This work has been partially supported by MEC Contracts Nos. BFM2003-08532, FISES2004-01399, FIS2004- 05073, and FIS2006-08533, by the European Commission Contract No. HPRN-CT-2002-00307, and by UCM-BCSH. We are grateful to T. Jörg and L. A. Fernández for interesting discussions.We perform intensive numerical simulations of the three-dimensional site-diluted Ising antiferromagnet in a magnetic field at high values of the external applied field. Even if data for small lattice sizes are compatible with second-order criticality, the critical behavior of the system shows a crossover from second-order to first-order behavior for large system sizes, where signals of latent heat appear. We propose “apparent” critical exponents for the dependence of some observables on the lattice size for a generic disordered first-order phase transition.engjournal articlehttp://dx.doi.org/10.1103/PhysRevB.76.064435https://journals.aps.orgopen access53Critical-behavior3 dimensionsMonte-CarloPhase-transitionsRandom-systemsModelUniversality.Física-Modelos matemáticos