N MXene*

We use DFT calculations to investigate the electronic and magnetic properties of Cr₂N MXene functionalized by oxygen at different coverages. Results show that oxygen adsorption happens at the H3 site. Pristine Cr₂N exhibits metallic and AFM characteristics. FM Cr oxide islands are obtained at 1/8 ML, become the system semiconductor. For ¼ and ½ ML the system is AFM, in both cases the material is half-metal. At 5/8 and ¾ ML coverages the material remains AFM, however, the material becomes semiconductor. For 7/8 ML AFM and FM configurations are degenerated, the AFM case is semiconductor and the FM is half-metal. For a coverage of 1ML the system becomes FM with half-metal characteristics. We show an effective way to tune the electronic properties of Cr₂N modifying the O coverage, laying the foundations to use these materials in the spintronics industry.