Tailoring the properties of the 2D ferromagnet CrSBr by lanthanide doping

The increasing fascination with 2D van der Waals (vdW) magnetic materials arises from their distinctive properties and promising applications in spintronics, magnonics, and quantum information technologies. Among them, CrSBr is a semiconductor that stands out owing to its high Curie temperature (TC similar to 146 K), air stability and tunable electronic and magnetic properties. Here, we present a systematic investigation of the effects of Dy doping (12.5%, 25%, and 50%) on the structural, electronic and magnetic properties of CrSBr monolayer. Our results reveal that Dy incorporation enhances magnetic anisotropy and modulates TC that arise from strong ferromagnetic and weak antiferromagnetic interactions. Additionally, we investigate the properties of DySBr, DySI and DySeI monolayers, which are isostructural to the CrSBr. Our results reveal the feasibility of exfoliating them down to the single layer and the presence of long-range magnetic order at low temperatures, relying on the combination of both weak exchange interactions and large spin-orbit coupling. This work provides insights into tuning the properties of CrSBr through rare earth doping, unlocking new possibilities for advanced applications at the 2D limit.