Layer-dependent electronic and magnetic properties for Cr2NO2 and Cr

Using the first-principles calculations, we study the stability, electronic and magnetic properties of monolayer, bilayer and trilayer Cr2NO2 and Cr2CO2. Stability is estimated from the thermal, mechanical and dynamical perspectives. Calculations show that the monolayer, bilayer and trilayer Cr2NO2 and Cr2CO2 are ferromagnetic ground states, and Cr2CO2 are nearly half-metals, and Cr2NO2 are half-metals with an integer total magnetic moment. For the monolayer, bilayer and trilayer Cr2NO2 and Cr2CO2, the Z-axis direction is their easy magnetization axis, and their magnetic anisotropy energies are obviously increased with the increase of layered number, the improvement of magnetic anisotropy energy origins from the enhancement of spin–orbit coupling strength. In addition, we also discuss the origin of gaps for monolayer, bilayer and trilayer half-metallic Cr2NO2.