Magnetocaloric effect in $\mathrm{Cu}_{3}$-type compounds using the Heisenberg antiferromagnetic model in a triangular ring

TL;DR

This paper provides a theoretical analysis of the magnetocaloric effect in Cu3-type antiferromagnetic compounds modeled by the Heisenberg model on a triangular lattice, highlighting temperature-dependent magnetic properties and potential cooling applications.

Contribution

It introduces a detailed numerical study of the magnetocaloric effect in Cu3-like systems considering various magnetic interactions and field orientations, extending understanding of their thermodynamic behavior.

Findings

Magnetization exhibits a 1/3 plateau at zero temperature.

Significant magnetocaloric effect observed near 1K temperature.

Similar behavior of the effect for magnetic fields parallel and perpendicular to the triangle plane.

Abstract

In this work we present a theoretical investigation into an antiferromagnetically coupled spin system, specifically ${\rm Cu}_{3}-X$ ($\mathrm{X=As,Sb}$), which exhibits an isosceles triangular configuration or slightly distorted equilateral triangular configuration, as previously identified in reference {[}Phys. Rev. Lett. \textbf{96}, 107202 (2006){]}. This system can be effectively represented by the Heisenberg model on a triangular structure, taking into account the exchange interaction, the Dzyaloshinskii-Moriya interaction, g-factors and external magnetic field, as delineated in the aforementioned reference. By using numerical approach we explore both zero-temperature and finite-temperature behaviors of a ${\rm Cu}_{3}$-like antiferromagnetically coupled spin system. At zero temperature, the system displays a 1/3 quasi-plateau magnetization, when the magnetic field is varied. Moreover, we place particular emphasis on magnetic properties including magnetization, magnetic susceptibility, entropy, and specific heat at finite temperatures. Furthermore, we investigate the magnetocaloric effect as a function of an externally imposed magnetic field, oriented both parallel and perpendicular to the plane of the triangular structure. Interestingly, these configurations demonstrate remarkably similar behavior for both orientations of the magnetic field. Our investigation also includes an analysis of the adiabatic curve, the Gr\"uneisen parameter, and the variation in entropy when applied or removed the magnetic field. The magnetocaloric effect is found to be more prominent in low the temperature region, typically at $T\sim1$K, for both parallel and perpendicular magnetic fields at $\sim4.5$T and $\sim5$T, respectively.