# Electronic structure and magnetism of transition metal dihalides: bulk to monolayer

## TL;DR

This study uses first-principles calculations to explore how the electronic and magnetic properties of transition metal dihalides change from bulk to monolayer, revealing potential ferromagnetic insulators suitable for 2D spintronics.

## Contribution

It provides a comprehensive analysis of the evolution of electronic and magnetic states in MX$_2$ monolayers, identifying new ferromagnetic insulators with significant anisotropy.

## Key findings

- FeX$_2$, NiX$_2$, CoCl$_2$, CoBr$_2$ monolayers are ferromagnetic insulators
- Magnetocrystalline anisotropies are sizable in these monolayers
- Spin-orbit coupling is crucial for accurate ground state prediction

## Abstract

Based on first-principles calculations, the evolution of the electronic and magnetic properties of transition metal dihalides MX$_2$ (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 FeX$_2$, NiX$_2$, CoCl$_2$ and CoBr$_2$ 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.