Monte Carlo simulations of the Blume–Emery–Griffiths model with S=3/2 and S=5/2

The magnetic properties of the Blume–Emery–Griffiths(BEG) model [1] with fractional large spin(S=3/2 and S=5/2) on two-dimensional square lattice are discussed by making use of the Monte Carlo (MC) simulation for the magnetization 〈Sz〉, sublattice magnetizations 〈Sz(A)〉 and 〈Sz(B)〉, the magnetic specific heat CM and spin structures. The ground state phase diagram of these models has been obtained for exchange parameter J2/J1 and anisotropy parameter D/J1. The temperature dependence of sublattice magnetizations 〈Sz(A)〉 and 〈Sz(B)〉 is investigated for various values of the anisotropy D. The relations between the Curie temperature Tc and the critical temperature Ts at which sublattice magnetizations begin taking different values are also studied. - Highlights: ► The MC simulation for the S=3/2 and 5/2 BEG model on the square lattice. ► The ground state phase diagrams are obtained. ► We investigate the spin structure and the temperature dependences of magnetization. ► The abnormal behaviors of magnetization are explained by sublattice magnetization.