Mixed-bond spin-1 Ising model with nonlinear interactions for the Fe-Mn alloys

TL;DR

This paper models the magnetic properties of Fe-Mn alloys using a mixed-bond spin-1 Ising model with nonlinear interactions, introducing a new ferromagnetic coupling dependence and a probability distribution for binary alloys, achieving good agreement with experimental data.

Contribution

It introduces a novel nonlinear dependence of ferromagnetic coupling on Mn concentration and a new probability distribution for mixed-bond alloys within the Ising model framework.

Findings

Good agreement with experimental data for Mn concentration q>0.11

New nonlinear ferromagnetic coupling dependence on Mn concentration

Effective field theory accurately models magnetic properties

Abstract

In this letter, we apply the mixed-bond spin-1 Ising model to the study of the magnetic properties of Fe-Mn alloys in the $\alpha$ phase by employing the effective field theory (EFT). Here, we suggest a new approach to the ferromagnetic coupling between nearest neighbours Fe-Fe that depends on the ratio between the Mn-Mn coupling and Fe-Mn coupling and of second power of the Mn concentration $q$ in contrast with linear dependence proposed in the other papers. Also, we propose a new probability distribution for binary alloys with mixed-bonds based on the distribution for ternary alloys and we obtain a very good agreement for all considered values of $q$ in $T-q$ plane, in particular for $q>0.11$.