Based on first-principles calculations, the evolution of the electronic and magnetic properties of transition metal dihalides MX2 (M= V, Mn, Fe, Co, Ni; X = Cl, Br, I) is analyzed from the bulk to the monolayer limit. A variety of magnetic ground states is obtained as a result of the competition between direct exchange and superexchange. The results predict that FeX2, NiX2, CoCl2 and CoBr2 monolayers are ferromagnetic insulators with sizable magnetocrystalline anisotropies. This makes them ideal candidates for robust ferromagnetism at the single layer level. Our results also highlight the importance of spin-orbit coupling to obtain the correct ground state.
@article{arxiv.1903.01789,
title = {Electronic structure and magnetism of transition metal dihalides: bulk to monolayer},
author = {Antia S. Botana and Michael R. Norman},
journal= {arXiv preprint arXiv:1903.01789},
year = {2019}
}