Manipulating Magnetism in Layered van der Waals Magnets via Structure–Property Engineering

Selected van der Waals magnets retain magnetic order down to the monolayer limit. Their sensitivity to layer number, local bonding, carrier density, and interfaces provides routes to magnetic control for spintronic and quantum devices. In this review, we focus on the control of magnetism in representative two-dimensional systems and organize the field from the perspective of structure–property relations and matched control strategies. We show that weak interlayer exchange enables magnetic-field switching in few-layer magnets, that spin-layer locking supports electric-field control in bilayer CrI3, that doping-sensitive exchange allows carrier-density tuning in CrI3 and Fe3GeTe2, that stacking-dependent interlayer coupling makes pressure and twist effective structural knobs, that strong magnetoelastic coupling gives strain direct access to magnetic phase boundaries, and that interfacial exchange and proximity effects turn van der Waals heterostructures into active platforms for engineering emergent magnetic states. Representative material families are discussed in this context, including chromium trihalides, phosphorus chalcogenides, Ge- and Te-based layered magnets, transition-metal chalcogenides, MnBi2Te4-family compounds, and oxyhalides. Together, these studies show that the field is evolving from the discovery of intrinsic two-dimensional magnets toward the mechanism-guided design of controllable magnetic phases, magnetic heterostructures, and functional spintronic and quantum devices.