Anomalies in the antiferromagnetic phase of metamagnets

Motivated by recent experiments on the metamagnet FeBr2, anomalies of the magnetization and the specific heat in the antiferromagnetic phase of related spin models are studied systematically using Monte Carlo simulations. In particular, the dependence of the anomalous behavior on competing intralayer interactions, the spin value and the Ising-like anisotropy of the Hamiltonian is investigated. Results are compared to experimental findings on FeBr2.