Above room-temperature two-dimensional ferromagnetic half-metals in Mn-based Janus magnets

TL;DR

This paper predicts stable 2D Mn-based Janus monolayers that are ferromagnetic half-metals with high Curie temperatures and strong in-plane magnetic anisotropy, promising for advanced spintronic devices.

Contribution

It introduces new stable 2D MnXY Janus monolayers with high Curie temperatures and intrinsic half-metallicity, expanding the materials options for spintronics.

Findings

Curie temperatures up to 418 K.

Large spin band gaps from 2.5 to 3.2 eV.

Strong in-plane magnetic anisotropy.

Abstract

Two-dimensional (2D) ferromagnets and their heterostructures offer fertile grounds for designing fascinating functionalities in ultra-thin spintronic devices. Here, by first-principles calculations, we report the discovery of energetically and thermodynamically stable 2D ferromagnets with very strong inplane magnetic anisotropy in MnXY (X = S, and Se; Y = Cl, Br and I) monolayers. Remarkably, we find that the Curie temperatures of the ferromagnetic MnSBr, MnSI, MnSeCl, and MnSeI monolayers are as high as 271, 273, 231 and 418 K, respectively. In addition, we demonstrate that these ferromagnetic monolayers are intrinsic half-metals with large spin band gaps ranging from 2.5 eV to 3.2 eV. When spin-orbit coupling is considered in these ferromagnetic monolayers, the nature of their half-metal is almost unaffected. Finally, the strong inplane magnetic anisotropy of MnSY (Y = Br, I) and MnSeY (Y = Cl, I) monolayers originate mainly from halogen and chalcogen atoms, respectively. Our work shows 2D Janus Mn-based ferromagnetic half-metals may have appealing functionalities in high-performance spintronic applications.