Toward intrinsic ultra-high-temperature ferromagnetism in a CrAuTe2/graphene heterosystem

Abstract

Exploring intrinsic two-dimensional (2D) ferromagnetic (FM) materials with high Curie temperatures (T_C) and large magnetic anisotropy energies (MAE) is one of the effective solutions to develop materials for high-performance spintronic applications. Using density functional theory calculations and high-throughput computations, we predict an intrinsic bimetallic FM monolayer, CrAuTe₂, which has a large MAE and high T_C. The results show that the value of the MAE can reach about 1.5 meV per Cr, and Monte Carlo simulations show that the T_C of monolayer CrAuTe₂ is about 840 K. Further analysis indicates that the joint effects of spin–orbit coupling (SOC) interaction and magnetic dipole–dipole interaction result in high in-plane magnetic anisotropy. In addition, this monolayer has good dynamic, thermal, and mechanical stabilities, which were confirmed by ab initio molecular dynamics simulations, phonon spectra, and elastic constants, respectively. In order to propose a practical synthesis approach, we built a CrAuTe₂/graphene van der Waals heterostructure, and found that the heterostructure does not affect the magnetic properties of monolayer CrAuTe₂. These findings appear promising for the future applications in nano-spintronics.