Predicted hexagonal titanium nitride monolayer as an intrinsic ferromagnetic semiconductor

Abstract

Two-dimensional (2D) magnetic semiconductors have great promising for energy-efficient ultracompact spintronics due to the low-dimensional ferromagnetic and semiconducting behavior. Here, we predict hexagonal titanium nitride monolayer (h-TiN) to be a ferromagnetic semiconductor by investigating stability, magnetism, and carrier transport of h-TiN using the first-principles calculations. The thermodynamical stability of h-TiN is revealed by phonon dispersion, molecular dynamics simulation and formation energy. The energy band structure shows that h-TiN is a ferromagnetic semiconductor with medium magnetic anisotropy, the magnetic moment of 1μB and the band gaps of 1.33 and 4.42 eV for spin-up and -down channels, respectively. The Curie temperature of h-TiN is estimated to be about 205 K by mean-field theory and not enhanced by the compressive and tensile strains. Higher carrier mobility, in-plane stiffness and conductivity indicate that h-TiN has favorable transport performance. The ferromagnetic semiconducting behavior is robust against the external strains, indicating that h-TiN could be a rare candidate for nanoscale spintronic devices.