Enhancing the Curie temperature of two-dimensional monolayer CrI₃ by introducing I-vacancies and interstitial H-atoms

The discovery of two-dimensional monolayer CrI₃ provides a promising possibility for developing spintronic devices. However, the low Curie temperature is an obstacle for practical applications. Here, based on the consideration of the superexchange interaction of ferromagnetic coupling, we investigate the effect of introducing I-vacancies and interstitial H-atoms on the Curie temperature of monolayer CrI₃ by using first-principles calculations and Monte Carlo simulations. Our theoretical conclusions show that the Curie temperature of Cr₈I₂₃ (CrI_2.875), Cr₈I₂₂ (CrI_2.75) and Cr₈I₂₄H (CrI₃H_0.125) significantly increases to 97.0, 82.5 and 112.4 K, respectively. Moreover, the magnetic moment of the Cr atom increases from 3.10 to 3.45 and 3.46μ_B in monolayers Cr₈I₂₃ and Cr₈I₂₂, respectively. We provide more alternative approaches to effectively enhance the Curie temperature of monolayer CrI₃, which will help both theoretical and experimental researchers to directly predict the change in Curie temperature of CrI₃ and its analogs through structural information.