# Manipulation of Emergent Collective Excitations via Composition Control in Mixed MPX3 Correlated 2D Antiferromagnets

## TL;DR

Researchers study how adding different elements to a 2D antiferromagnet material affects its magnetic and optical properties.

## Contribution

The study shows substituent introduction is a powerful way to control collective excitations in 2D antiferromagnets.

## Key findings

- SOX emission is strongly suppressed by substituents, with Fe having the strongest effect.
- 2M scattering is more resilient to substitution and less affected by Fe.
- Substituent type and concentration significantly alter magnetic and optical properties.

## Abstract

Transition metal (i.e., Mn, Fe, Cr) and chalcogen (Se) substituents are introduced into single‐crystalline NiPS3, and the evolution of the two emergent quasi‐particle excitations characteristic to the XXZ correlated antiferromagnetism of NiPS3 (i.e., spin orbit entangled exciton (SOX) and two‐magnon scattering (2M )) are investigated as functions of substituent concentration through comprehensive room‐ and low‐temperature photoluminescence (PL) and Raman spectroscopy studies. These findings are further correlated with the magnetic properties of the same set of compounds reported in prior studies. The work revealed that the SOX emission intensities and linewidths are mainly controlled by the magnetic anisotropy and spin orientations, and are strongly suppressed by the introduction of substituents. The suppression depends on the type of substituent, with Fe affecting the SOX emission more than Mn and Cr. The 2 m scattering is linked to short‐range correlations and exhibits greater resiliency against metal atom substitution. While the 2M  peak at low temperature gets suppressed and red‐shifted in frequency with increasing concentrations of all the substituents, Fe induces the weakest suppression compared to all other substituents. Altogether, these findings revealed the introduction of substituents as a powerful route to control the emergent collective excitations in NiPS3 and mixed‐MPX3 materials.

Transition metal and chalcogen substituents are introduced into 2D antiferromagnet, NiPS3, and comprehensive photoluminescence and Raman spectroscopy studies are conducted to investigate how spin orbit entangled exciton and two magnon scattering evolve as functions of substituent concentration. Findings revealed the introduction of substituents as a powerful route to control the emergent collective excitations.