Magnetism in Two-Dimensional Ilmenenes: Intrinsic Order and Strong Anisotropy

TL;DR

This paper explores the magnetic and electronic properties of two-dimensional ilmenene materials, revealing intrinsic antiferromagnetism, ferromagnetism in certain compositions, and significant anisotropy, with implications for spintronic applications.

Contribution

It provides a theoretical analysis of 2D transition-metal ilmenenes, highlighting their magnetic order, anisotropy, and potential for synthesis and spintronic use.

Findings

Ilmenenes exhibit intrinsic antiferromagnetic coupling.

Late 3d metal ilmenenes can be ferromagnetic or spin compensated.

Magnetocrystalline anisotropy depends on 3d shell filling.

Abstract

Iron ilmenene is a new two-dimensional material that has recently been exfoliated from the naturally-occurring iron titanate found in ilmenite ore, a material that is abundant on earth surface. In this work, we theoretically investigate the structural, electronic and magnetic properties of 2D transition-metal-based ilmenene-like titanates. The study of magnetic order reveals that these ilmenenes usually present intrinsic antiferromagnetic coupling between the 3d magnetic metals decorating both sides of the Ti-O layer. Furthermore, the ilmenenes based on late 3d brass metals, such as CuTiO$_3$ and ZnTiO$_3$, become ferromagnetic and spin compensated, respectively. Our calculations including spin-orbit coupling reveal that the magnetic ilmenenes have large magnetocrystalline anisotropy energies when the 3d shell departs from being either filled or half-filled, with their spin orientation being out-of-plane for elements below half-filling of 3d states and in-plane above. These interesting magnetic properties of ilmenenes make them useful for future spintronic applications because they could be synthesized as already realized in the iron case.