Bethe approach study of the mixed spin-1/2 and spin-5/2 Ising system in the presence of an applied magnetic field

TL;DR

This study analyzes the phase transitions of a mixed spin-1/2 and spin-5/2 Ising model on a Bethe lattice under magnetic field using recursion relations, revealing primarily second-order transitions.

Contribution

It provides a detailed phase diagram and transition analysis for the mixed-spin Ising model with magnetic field, using the Bethe lattice approach.

Findings

Ground-state phase diagram constructed.

Model exhibits only second-order phase transitions.

Temperature phase diagrams analyzed for various coordination numbers.

Abstract

The mixed spin-1/2 and spin-5/2 Ising model is investigated on the Bethe lattice in the presence of a magnetic field $h$ via the recursion relations method. A ground-state phase diagram is constructed which may be needful to explore important regions of the temperature phase diagrams of a model. The order-parameters, the corresponding response functions and internal energy are thoroughly investigated in order to typify the nature of the phase transition and to get the corresponding temperatures. So, in the absence of the magnetic field, the temperature phase diagrams are displayed in the case of an equal crystal-field on the $(k_{\textrm{B}}T/|J|, \,D/|J|)$ plane when $q=3,4$, $5$ and $6$. The model only exhibits the second-order phase transition for appropriate values of physical parameters of a model.