The Ising type model with arbitrary value of spin is investigated within the two-particle cluster approximation. For this model on hypercubic lattices the expressions for the pair correlation functions in q-space are obtained. For Blume-Emery-Griffiths model (S=1) on a simple cubic lattice with bilinear K, biquadratic K' interactions and single-ion anisotropy D, a projection of the phase diagram on D/K-K'/K plane is constructed. The temperature dependences of <S^z>, <(S^z)^2> and pair correlation functions at q=0 are calculated at various values of parameters D/K and K'/K.Comments: Figs. 26, Refs. 25, Tabs. 0.
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