Electronic and magnetic properties of van der Waals ferromagnetic semiconductor VI3

Magnetic van der Waals materials with intrinsic magnetic properties provide the ideal platform for exploring magnetism in the low-dimensional limit. In this work, we investigate the electronic and magnetic properties of the ${\mathrm{VI}}_{3}$ material, a new member of the ferromagnetic van der Waals materials. First-principles results confirm the Mott-insulator state as its electronic ground state. The half-metallic state as reported in the literature is a metastable state, with a total energy 0.2--0.3 eV per ${\mathrm{VI}}_{3}$ higher than the Mott-insulator state. Magnetocrystalline anisotropy calculations confirm an out-of-plane magnetic easy axis of the ${\mathrm{VI}}_{3}$ monolayer. We predict the interlayer exchange coupling of the ${\mathrm{VI}}_{3}$ bilayer to be determined by the interlayer stacking order, ferromagnetic at the most stable and antiferromagnetic at the metastable stacking orders, respectively, reminiscent of the ${\mathrm{CrI}}_{3}$ material.