Compensation temperatures induced by longitudinal fields in a mixed spin Ising ferrimagnet

We have calculated the free energy of a mixed spin Ising ferrimagnetic model from a mean field approximation of the Hamiltonian. By minimizing the free energy, we obtain the equilibrium magnetizations and the compensation points. A mixed spin-2 and spin-5/2 Ising ferrimagnet with different single-ion anisotropies on a simple cubic lattice (z=6) is studied. We have used a mean field method and found that the anisotropy of the mixture plays an important role as regards the existence and location of compensation points. The existence of a compensation temperature and its dependence on the external field are the main focus of investigation.