First-principles investigation of electronic properties of NiTeO4 using DFT and DFT+U frameworks

Abstract

 Nickel-based compounds such as materials synthesized from NiO-TeO₂ have been an active area of research in part due to interesting structure-dependent properties including electric and magnetic orders. Among these materials is NiTeO₄. To characterize its properties, we applied first-principles density functional theory (DFT) and DFT+U (Hubbard parameter U = 6.2 eV) to calculate and compare the predictions on Fermi energy, band structure, band gap, and density of states of primitive cell NiTeO₄. Band structure calculations using DFT show no gap between the valence and conduction bands, while DFT+U calculations give a band gap of 0.0008 eV, hinting at the semi-metallic nature of NiTeO₄. Density of states calculations using DFT identify more states available for electron occupancy right above the Fermi level compared to DFT+U calculations.