Ferromagnetic GdX (X = Cl, Br) Monolayers with Large Perpendicular Magnetic Anisotropy and High Curie Temperature

Abstract

Two-dimensional (2D) ferromagnets with high Curie temperatures (T C ) and large perpendicular magnetic anisotropy (PMA) are rare, but have great potential in the field of spintronics. The present work investigates the electronic and magnetic properties of GdX (X = Cl and Br) monolayers and the two layers of GdCl/GdBr heterojunctions by conducting in-depth theoretical calculations. As expected, both GdCl and GdBr monolayers are ferromagnetic and have large magnetic moments of ∼8 μ B per Gd atom. Besides, they both show large PMA with magnetic anisotropy energies of 0.88 and 0.85 meV/unit cell and ultrahigh T C of 826 and 704 K, respectively. Significantly, they both have topological properties and spin-orbit-induced energy band reversion. In addition, we found two stable stacking configurations for the GdCl/GdBr bilayer heterojunction. The ultrahigh T C and topological properties are maintained in the two stacking configurations. Their easy magnetization axes shift from out-of-plane to in-plane directions as a result of the competition mainly between the Gd p and Gd d orbitals. These properties endow GdCl and GdBr monolayers with great potential for practical applications in the field of spintronic devices at the nanoscale.

Alkali metal-doped two-dimensional Janus Cr2Br3I3 monolayers with the quantum anomalous Hall effect

“…The adsorption energy (E ads ), 15 the cohesive energy (E coh ), 23,39,40 and the formation energy (E form ) 23,41,42 of Li/Na/ K-doped ML Cr 2 Br 3 I 3 were calculated by the following formulas:…”

Intrinsic half-metallicity in two-dimensional Cr2TeX2 (X = I, Br, Cl) monolayers

“…And the similar phenomena also occur in other structures, such as the GdX 2 and GdX (X = Cl, Br) monolayers, in which the MAEs of the GdCl 2 and GdCl monolayers are bigger than those of the GdBr 2 and GdBr ones. 55,56 The large out-of-plane MAE makes the Cr 2 TeI 2 monolayer possessing potential applications in high-density information storage.…”