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Abstract Magnetic van der Waals heterostructures provide a unique platform to study magnetism and spintronics device concepts in the 2D limit. Here, studies of exchange bias from the van der Waals antiferromagnet CrSBr acting on the van der Waals ferromagnet Fe₃GeTe₂(FGT) are reported. The orientation of the exchange bias is along the in‐plane easy axis of CrSBr, perpendicular to the out‐of‐plane anisotropy of the FGT, inducing a strongly tilted magnetic configuration in the FGT. Furthermore, the in‐plane exchange bias provides sufficient symmetry breaking to allow deterministic spin–orbit torque switching of the FGT in CrSBr/FGT/Pt samples at zero applied magnetic field. A minimum thickness of the CrSBr of >10 nm is needed to provide a non‐zero exchange bias at 30 K. 

Abstract CrSBr is an air‐stable two‐dimensional (2D) van der Waals semiconducting magnet with great technological promise, but its atomic‐scale magnetic interactions—crucial information for high‐frequency switching—are poorly understood. An experimental study is presented to determine the CrSBr magnetic exchange Hamiltonian and bulk magnon spectrum. TheA‐type antiferromagnetic order using single crystal neutron diffraction is confirmed here. The magnon dispersions are also measured using inelastic neutron scattering and rigorously fit the excitation modes to a spin wave model. The magnon spectrum is well described by an intra‐plane ferromagnetic Heisenberg exchange model with seven nearest in‐plane exchanges. This fitted exchange Hamiltonian enables theoretical predictions of CrSBr behavior: as one example, the fitted Hamiltonian is used to predict the presence of chiral magnon edge modes with a spin‐orbit enhanced CrSBr heterostructure. 

Abstract Magnetic van der Waals (vdW) materials are a promising platform for producing atomically thin spintronic and optoelectronic devices. The A‐type antiferromagnet CrSBr has emerged as a particularly exciting material due to its high magnetic ordering temperature, semiconducting electrical properties, and enhanced chemical stability compared to other vdW magnets. Exploring mechanisms to tune its magnetic properties will facilitate the development of nanoscale devices based on vdW materials with designer magnetic properties. Here it is investigated how the magnetic properties of CrSBr change under pressure and ligand substitution. Pressure compresses the unit cell, increasing the interlayer exchange energy while lowering the Néel temperature. Ligand substitution, realized synthetically through Cl alloying, anisotropically compresses the unit cell and suppresses the Cr‐halogen covalency, reducing the magnetocrystalline anisotropy energy and decreasing the Néel temperature. A detailed structural analysis combined with first‐principles calculations reveals that alterations in the magnetic properties are intricately related to changes in direct Cr–Cr exchange interactions and the Cr–anion superexchange pathways. Further, it is demonstrated that Cl alloying enables chemical tuning of the interlayer coupling from antiferromagnetic to ferromagnetic, which is unique among known two‐dimensional magnets.