Equilibrium Properties of the Spin-1 Ising System with Bilinear, Biquadratic and Odd Interactions

Authors: Cabir TEMİRCİ, Ali KÖKÇE, Mustafa KESKİN

Abstract: The equilibrium properties of the spin-1 Ising system [1] Hamiltonian with arbitrary bilinear (J), biquadratic (K) and odd (L), which is also called dipolar-quadrupolar [2], interactions are studied for zero magnetic field by the lowest approximation of the cluster variation method [3]. The odd interaction is combined with the bilinear and biquadratic exchange interactions by the geometric mean. In this system, phase transition depends on the ratio of the coupling parameter, \alpha =J/K, therefore, changing of the phase transitions with \alpha is investigated extensively and found that for \alpha\le 1 and \alpha\ge 2000 a second-order phase transition occur, and for 1