Magneto-Optical Sensing of the Pressure Driven Magnetic Ground States in Bulk CrSBr

Abstract

Competition between exchange interactions and magnetocrystalline anisotropy may bring new magnetic states that are of great current interest. An applied hydrostatic pressure can further be used to tune their balance. In this work, we investigate the magnetization process of a biaxial antiferromagnet in an external magnetic field applied along the easy axis. We find that the single metamagnetic transition of the Ising type observed in this material under ambient pressure transforms under hydrostatic pressure into two transitions, a first-order spin-flop transition followed by a second-order transition toward a polarized ferromagnetic state near saturation. This reversible tuning into a new magnetic phase is obtained in layered bulk CrSBr at low temperature by varying the interlayer distance using high hydrostatic pressure, which efficiently acts on the interlayer magnetic exchange and is probed by magneto-optical spectroscopy.

CrSBr: An Air-Stable, Two-Dimensional Magnetic Semiconductor

“…40 A microscopic spin model shows that CrSBr sits close to the phase boundary between a spin-flip and spin-flop regime such that extrinsic effects (e.g., strain) may explain the conflicting data. 41 The proximity of CrSBr to the spin-flip/spin-flop phase boundary again highlights that competing magnetic interactions may contribute to the complex magnetic behavior below T N .…”

Charge Transfer and Asymmetric Coupling of MoSe2 Valleys to the Magnetic Order of CrSBr

“…Recently, van der Waals (vdW) magnetic materials have attracted increasing attention because of their unique magnetic properties and possible applications in spintronics. − Several studies were performed in heterostructures using magnetic materials and monolayer transition metal dichalcogenides (TMDs). − ,− These heterostructures employ magnetic proximity effects to modify the physical properties of the ML TMD adjacent to the magnetic material and therefore offer new opportunities for engineering magnetic heterostructures . Actually, recent studies evidenced an enhanced valley splitting of WSe 2 and WS 2 monolayers on the ferromagnetic (FM) material EuS, , a giant zero-field valley splitting of MoSe 2 /CrBr 3 , asymmetric magnetic proximity interactions in MoSe 2 /CrBr 3 , and an anomalous temperature dependence of the MoSe 2 /MnPSe 3 excitonic peak below the Néel temperature ( T N ) .…”

“…The layered magnetic material CrSBr is a vdW direct gap semiconductor with A-type AFM and Neél temperature of 132 K in its bulk form. − In addition, CrSBr presents another phase transition around the temperature of T = 40 K ,, which is not well understood but might be related to crystal defects or spin-freezing effects . The CrSBr crystal consists of layers with rectangular unit cells in the plane ( â – b̂ ) which are stacked along the ĉ axis to produce an orthorhombic structure [Figure (b)].…”

“…Changes in the static magnetic configuration induced by applying a magnetic field, for instance, directly impact the exciton energy. The electronic band structure, and consequently the energy of excitons in CrSBr, are sensitive to the interlayer magnetic exchange interaction which can be used to probe its magnetic properties. ,,, …”

“…In Figure (d), the PL spectrum of CrSBr at 3.6 K is displayed in the left part. Several PL peaks are observed below 1.4 eV and associated with excitons, ,,, defects, and strong exciton–photon coupling…”