Electronic and magnetic properties of CrI₃ grain boundary

Two dimensional (2D) magnetic materials such as monolayer CrI₃ attracted many attentions owing to their intrinsic ferromagnetism and spintronic applications. As an inevitable line defect, grain boundary can affect many properties of 2D materials. However, the effects of grain boundary in CrI₃ have not been considered much so far. In this paper, we investigated the thermodynamic stabilities, electronic and magnetic properties of 13 CrI₃ grain boundaries by using the first principle calculations. We found that, most zigzag type grain boundaries are more stable than armchair ones, and some of them have much lower formation energy than that of bared edge under different chemical potentials. We also found that, most grain boundaries can increase both the magnetic moments and Curie temperatures at the same time. Furthermore, based on the atomic structure of a stable grain boundary, we proposed more stable CrI₃-CrI₂ lateral heterostructure and graphdiyne-like hybrid system. We proved that, both the heterostructure and hybrid system have the tunable electronic and magnetic properties, which may pave the way for new potential applications.