Abstract
Two-dimensional (2D) magnetic materials are of great current interest for their promising applications in spintronics. Here we propose the van der Waals (vdW) material to be a 2D Ising ferromagnet (FM), using density functional calculations, crystal field level diagrams, superexchange model analyses, and Monte Carlo simulations. The ground state in the trigonal crystal field gives rise to the 2D Ising FM due to a significant single ion anisotropy (SIA) and enhanced FM superexchange both associated with the and states of ions. We find that a tensile strain on the monolayer further stabilizes the ground state, and its Curie temperature would increase from 70 to 90–110 K under a 2.5%–5% tensile strain. Moreover, we suggest a group of spin-orbital states with a strong SIA which may help to search more 2D Ising magnets.
- Received 12 September 2019
- Accepted 27 February 2020
DOI:https://doi.org/10.1103/PhysRevB.101.100402
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