Phase diagrams of the spin-5/2 Blume–Capel model

Abstract

We have used the Curie–Weiss mean-field approximation to study the effects of the random single-ion anisotropy and random magnetic field in the phase diagram and thermodynamic properties of the spin-5/2 Blume–Capel model. The phase diagrams have been presented in the temperature T∕J versus strength random single-ion anisotropy D∕J and strength random magnetic field h∕J planes. The magnetization dependence was plotted as a function of temperature and the strength single-ion anisotropy. These diagrams showed that the different phase transition types, first-or second-order between the ferromagnetic and paramagnetic phases, are dependent on the random parameters. Therefore, within these conditions, the model presents tricritical behavior.