Tuning Magnetism in Atomically Thin CrI₃ by Hydrostatic Pressure

Atomically thin CrI₃ has recently been discovered as a two-dimensional magnetic semiconductor. Remarkably, while monolayer CrI₃ is ferromagnetic, antiferromagnetic inter-layer coupling is favored in few-layer CrI₃. Because the interlayer exchange coupling is relatively weak, it is expected to be sensitive to external perturbations. Indeed, control of the interlayer magnetic order in atomically thin CrI₃ by an electric field and electrostatic doping has recently been demonstrated. Here we report an experimental study of the magnetic order in few-layer CrI₃ under hydrostatic pressure. We utilized the giant tunneling magnetoresistance observed in CrI₃ spin-filter devices to probe the interlayer magnetic order. We found that the magnetic properties of atomically thin CrI₃ can be tuned by applying a moderate pressure.