Van der Waals CrSBr alloys with tunable magnetic and optical properties

TL;DR

This study investigates CrSBr alloys with Cl, revealing how halogen mixing tunes magnetic and optical properties, including exciton energies and magnon frequencies, with potential applications in spintronics.

Contribution

It demonstrates the tunability of magnetic and optical properties in CrSBr alloys through halogen mixing, combining experimental Raman and magneto-optical data.

Findings

Exciton energies change weakly with composition.

Large variations in saturation magnetic fields observed.

Magnon energies can be tuned via alloy composition.

Abstract

Van der Waals magnets are attracting a lot of attention for their potential integration in spintronic and magnonic technologies. CrSBr is an A-type antiferromagnet that shows a coupling between its electronic band structure and magnetic properties. This property is appealing for applications and it also offers the possibility to investigate magnetic ground states and GHz magnons using visible optics techniques. Using Raman scattering and (magneto)-optical experiments, we describe the magnetic and optical properties of alloys of CrSBr$_{(1-x)}$Cl$_x$ with $x<0.46$. Similar to CrSBr, these alloys are direct band gap semiconductors with a coupling of their electronic and magnetic properties. Exciton energies evolve weakly with composition and we describe the large changes in the saturation magnetic fields and their implications on the magnetic properties. We show that both the interlayer magnetic exchange and electronic interactions are modified by the halogen mixing, offering the possibility to tune magnon energies with alloy composition.