Very Long Term Stabilization of a 2D Magnet down to the Monolayer for Device Integration

2D materials have recently demonstrated a strong potential for spintronic applications. This has been further reinforced by the discovery of ferromagnetic 2D layers. Nevertheless, the fragility of many 2D magnetic materials to ambient conditions has so far hindered their faster characterization and integration into devices. We report here on a simple large-scale method that allows to stabilize strongly air sensitive materials, such as CrBr3, down to the monolayer limit with ultrathin barriers grown by atomic layer deposition (ALD). We focus on MgO as a passivation layer to additionally serve as tunnel spin injection barrier for spintronic applications. We develop a special removable combined protection–encapsulation stack to better preserve 2D material and MgO barrier qualities during device fabrication. This scheme allows to observe 2D ferromagnet stability over one year of air exposure and to demonstrate CrBr3 successful integration into vertical devices. Overall, these results highlight an efficient way to handle these materials in ambient conditions, unlocking possibilities to fasten their advanced characterization and ease their integration into devices.