# Dependence of the magnetic interactions in MoS$_2$ monolayer on Mn-doping configurations

## TL;DR

This study uses DFT+U calculations to analyze how different Mn doping configurations in MoS$_2$ monolayers influence magnetic interactions, revealing that dopant arrangement critically affects ferromagnetism.

## Contribution

It provides new insights into how Mn dopant configurations affect magnetic properties in MoS$_2$, highlighting the importance of dopant ordering for ferromagnetism.

## Key findings

- Ferromagnetic interactions are strongest at second nearest neighbor Mn sites.
- Clustering of Mn reduces ferromagnetic exchange energies.
- Ordered Mn dopants enhance potential ferromagnetism.

## Abstract

Understanding the magnetic properties of the various Mn doping configurations that can be encountered in $2H$-MoS$_2$ monolayer could be beneficial for its use in spintronics. Using density functional theory plus Hubbard U (DFT$+$U) approach, we study how a single isolated, double- and triple-substitution configurations of Mn atoms within a MoS$_2$ monolayer could contribute to its total magnetization. We find that the doping-configuration plays a critical role in stabilizing a ferromagnetic state in a Mn-doped MoS$_2$ monolayer. Indeed, the Mn-Mn magnetic interaction is found to be ferromagntic and strong for Mn in equidistant substitution positions where the separation average range of 6-11 {\AA}. The strongest ferromagnetic interaction is found when substitutions are in second nearest neighbors Mo-sites of the armchair chain. Clustering is energetically favorable but it strongly reduces the ferromagnetic exchange energies. Our results suggest that ordering the Mn dopants on MoS$_2$ monolayer is needed to increase its potential ferromagnetism.