Goodenough-Kanamori-Anderson high-temperature ferromagnetism in tetragonal transition-metal xenes

TL;DR

This paper demonstrates that certain tetragonal transition-metal xenes exhibit stable high-temperature ferromagnetism driven by GKA superexchange rules, with potential applications in spintronics and 2D heterostructures.

Contribution

It identifies stable tetragonal transition-metal xenes with high Curie temperatures and provides an orbitally-resolved analysis of their magnetic interactions, advancing 2D ferromagnetic material design.

Findings

Curie temperature above 300 K in CrC and MnC

Stable planar GKA ferromagnetism in selected tTMXs

Orbitally-resolved analysis elucidates magnetic exchange mechanisms

Abstract

Seminal Goodenough-Kanamori-Anderson (GKA) rules provide the inceptive understanding of the superexchange interaction of two magnetic metal ions bridged with an anion, and suggest fostered ferromagnetic interaction for orthogonal bridging bonds. However, there are no examples of two-dimensional (2D) materials with structure that optimizes the GKA arguments towards enhanced ferromagnetism and its critical temperature. Here we reveal that an ideally planar GKA ferromagnetism is indeed stable in selected tetragonal transition-metal xenes (tTMXs), with Curie temperature above 300~K found in CrC and MnC. We provide the general orbitally-resolved analysis of magnetic interactions that supports the claims and sheds light at the mechanisms dominating the magnetic exchange process in these structures. With recent advent of epitaxially-grown tetragonal 2D materials, our findings earmark tTMXs for facilitated spintronic and magnonic applications, or as a desirable magnetic constituent of functional 2D heterostructures.