The effect of uniaxial crystal-field anisotropy on magnetic properties of the superexchange antiferromagnetic Ising model

TL;DR

This paper provides an exact analysis of how uniaxial crystal-field anisotropy influences the magnetic properties of a superexchange antiferromagnetic Ising model, revealing detailed phase diagrams and thermodynamic behaviors.

Contribution

It introduces an exact solution linking the generalized Fisher model with the standard Ising model, accounting for arbitrary spin values and external fields, expanding understanding of anisotropic magnetic systems.

Findings

Crystal-field anisotropy significantly alters phase diagrams.

External magnetic field impacts ground-state and finite-temperature properties.

Exact thermodynamic quantities are derived for various spin values.

Abstract

The generalized Fisher super-exchange antiferromagnetic model with uniaxial crystal-field anisotropy is exactly investigated using an extended mapping technique. An exact relation between partition function of the studied system and that one of the standard zero-field spin-1/2 Ising model on the corresponding lattice is obtained applying the decoration-iteration transformation. Consequently, exact results for all physical quantities are derived for arbitrary spin values S of decorating atoms. Particular attention is paid to the investigation of the effect of crystal-field anisotropy and external longitudinal magnetic field on magnetic properties of the system under investigation. The most interesting numerical results for ground-state and finite-temperature phase diagrams, thermal dependences of the sublattice magnetization and other thermodynamic quantities are discussed.