Impact of Dimensionality on the Magnetocaloric Effect in Two-dimensional Magnets

TL;DR

This paper investigates how reducing dimensionality to two dimensions affects the magnetocaloric effect in ferromagnetic materials, revealing benefits and challenges for energy-efficient cooling applications.

Contribution

It provides a systematic atomistic simulation study of 2D versus 3D ferromagnets, highlighting key properties influencing magnetocaloric performance and proposing GdSi$_2$ as a promising 2D magnetocaloric material.

Findings

2D features enhance magnetic susceptibility and transition sharpness.

Higher lattice heat capacity in 2D can limit temperature change.

GdSi$_2$ identified as a potential magnetocaloric material near hydrogen liquefaction temperature.

Abstract

Magnetocaloric materials, which exploit reversible temperature changes induced by magnetic field variations, are promising for advancing energy-efficient cooling technologies. The potential integration of two-dimensional materials into magnetocaloric systems represents an emerging opportunity to enhance the magnetocaloric cooling efficiency. In this study, we use atomistic spin dynamics simulations based on first-principles parameters to systematically evaluate how magnetocaloric properties transition from three-dimensional (3D) to two-dimensional (2D) ferromagnetic materials. We find that 2D features such as reduced Curie temperature, sharper magnetic transition, and higher magnetic susceptibility are beneficial for magnetocaloric applications, while the relatively higher lattice heat capacity in 2D can compromise achievable adiabatic temperature changes. We further propose GdSi$_2$ as a promising 2D magnetocaloric material near hydrogen liquefaction temperature. Our analysis offers valuable theoretical insights into the magnetocaloric effect in 2D ferromagnets and demonstrates that 2D ferromagnets hold promise for cooling and thermal management applications in compact and miniaturized nanodevices.