Numerical study of a two-sublattice Heisenberg ferrimagnetic model: Green's function method

The magnetic properties of a mixed spin Heisenberg ferrimagnetic system on a square lattice are investigated with the aid of the Green's function technique. The magnetization curve exhibits the first-order phase transition for the some negative values of the single-ion anisotropy parameters. When the system is subject to an external magnetic field, one observes the first-order phase transition where the magnetization jumps. We have observed hysteresis loops at all temperatures until the critical temperature. We found that the coercive field makes a minimum at the compensation temperature. The reciprocal susceptibility has hyperbolic behavior at temperatures greater than critical temperature. © 2013 AIP Publishing LLC.