Compensation Temperature of a Mixed Ising Ferrimagnetic Model in the Presence of External Magnetic Fields

The behavior of the compensation temperature of a mixed Ising ferrimagnetic system on a square lattice in which the two interpenetrating square sublattices have spins $\sigma$ ($\pm 1/2$) and spins $S$ ($\pm 1,0$) has been studied with Monte Carlo methods. Our model includes nearest and next-nearest neighbor interactions, a crystal field and an external magnetic field. This model is relevant for understanding bimetallic molecular ferrimagnetic materials. We found that there is a narrow range of parameters of the Hamiltonian for which the model has compensation temperatures and that the compensation point exists only for small values of the external field.