Two-Fold Enhancement of Curie Temperature in Monolayer CrI3 by High Pressure

In recent years, the discovery of the two-dimensional (2D) intrinsically ferromagnetic monolayer CrI3 has opened up promising avenues for the advancement of spintronic devices. Nevertheless, the relatively low Curie temperature poses a significant challenge for practical applications. Herein, we determine changes in the superexchange interaction of ferromagnetic coupling caused under pressure by using first-principles calculations and Monte Carlo simulations. Based on the superexchange interaction of ferromagnetic coupling, the effect of applying high pressure on the Curie temperature of monolayer CrI3 is investigated. With a pressure coefficient of 2.0%, the Curie temperature is enhanced to 97.3 K, which is nearly double that of the monolayer CrI3 without pressure. In addition, the direction of the easy magnetization axis changes from the out-of-plane to the in-plane one when the pressure coefficient is 1.2%. Meanwhile, the band gap of monolayer CrI3 can be transformed from indirect to direct by applying high pressure. Our work enriches the process of modulating the magnetic and electronic properties of 2D monolayer materials.