Study of the magnetocaloric effect and magnetic properties in the spin-3/2 Blume–Capel model

Abstract

In this study, the magnetic properties and the magnetocaloric effect of the spin-3/2 Blume–Capel model were explored through the Mean Field Theory, developed through a variational principle based on the Bogoliubov inequality to derive thermodynamic expressions such as free energy, magnetization and entropy. The analysis focused on magnetization, free energy and phase diagram with the presence of an external field greater than and equal to zero. The magnetocaloric effect was evaluated by observing the magnetic entropy changes due to different variations of the external magnetic field. Results were analyzed for both continuous and first-order phase transitions. To validate the magnetic entropy results, Maxwell’s relations were applied in the regions with continuous magnetization variations, and the Clausius–Clapeyron equation was used in the regions with magnetization discontinuity.