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

The discovery of two-dimensional monolayer CrI 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 CrI by using first-principles calculations and Monte Carlo simulations. Our theoretical conclusions show that the Curie temperature of CrI (CrI), CrI (CrI) and CrIH (CrIH) 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 3.46 in monolayers CrI and CrI, respectively. We provide more alternative approaches to effectively enhance the Curie temperature of monolayer CrI, which will help both theoretical and experimental researchers to directly predict the change in Curie temperature of CrI and its analogs through structural information.