Phase transition properties of the spin-1 Blume–Emery–Griffiths model with random transverse crystal field

Abstract

Phase transition properties of a spin-1 Blume–Emery–Griffiths model (BEGM) with random transverse crystal field is studied by the effective field theory for a simple cubic lattice. In T − D x space, we obtain the phase diagrams with the ratio α between the biquadratic interaction and the exchange interaction as well as a tunable parameter l of the transverse crystal field. The tricritical point (TCP) appears at α < 0 , which undergoes a crossover from positive to negative direction of the transverse crystal field when l < 0 . The TCP cannot be observed for α > 0 . The maximum critical temperature increases with the increase of α . The position of the peak value tends to the drift of negative or positive direction for a different magnitude or an imperfect ( ± ) transverse crystal field distribution. In T − α space, the range of ordered phase is magnified when the ratio is changed from α < 0 to α > 0 . The random transverse crystal field obviously affects the TCP.