Magnetic properties and phase diagrams of the mixed spin-( 1/2 , 3/2 ) Ising–Heisenberg model in the mean field approximation

Abstract

In this paper, the effects of the longitudinal D z and the transverse D x crystal fields on the mixed spin-( 1/2 , 3/2 ) Ising–Heisenberg model have been studied. The thermodynamic properties of the model are obtained by using a new approach of the mean field approx- imation (MFA). The thermal variations of the order-parameters and the total magnetic susceptibility of the model are carefully investigated to obtain the phase diagrams on the (D x /J, k B T /J) planes for z = 3 and on the (D z /J, k B T /J) planes for z = 3, 4 and 6. The existence of compensation temperatures between the sublattice magnetizations, T comp,M , and the two components of the quadrupole moments, T comp,Q , are observed. Our results are compared with other existing works in the literature and reliable agreements are found.