Metal insulator transition in FeWN2: DFT and DFT+U study

We have studied the electronic and magnetic properties of layered ternary transition metal nitrides, FeWN2. We found that the density functional theory (DFT) based approaches within the generalized gradient approximation frameworks fail to predict the correct ground state configuration. While the DFT plus on-site repulsion U method (DFT+U) predict the AF ordering which it's in good agreement with experiment. We found that the metal-insulator transition is accompanied by a magnetic phase transition which occurred at the same time, a ferromagnetic-metallic to antiferromagnetic-insulating transition where Ueff=3eV. It is shown also that magnetism and correlation effects are important in band-gap formation in this compound. Our calculated results by DFT-mBJ show the same trend of the band gap. The fully spin polarized DOS at the Fermi level in FM phase makes from FeWN2 a promising candidate material for spintronic applications.