Ti2VGe Heuslerene: theoretical prediction of a novel 2D material

Abstract

The possibility of a new graphene-like slice of the Heusler compounds, named Heuslerene, is predicted. Calculations for the 2D and 3D structures of the Ti₂VGe are performed via density functional theory (DFT) and a full-potential linearized augmented plane-waves plus local orbitals (FP-LAPW+lo) method. The exchange correlation potential has been approximated by the generalized gradient approximation (GGA) and local density approximation (LDA), for the mechanical calculations and GGA+U+mBJ scheme for the electronic and optical parts. Stability of the Ti₂VGe Heuslerene nano-sheet is explored from various points of view, and ended up with the result that it is completely stable not only statically, but also from the dynamic standpoint. Magnetic calculations predict it would be a ferromagnetic (FM) half-metal with a magnetic momentum of 1.0 μ_B and an energy gap of 1.12 eV in the down spin. Its optical parameters, such as the real and imaginary parts of the dielectric function, the absorption coefficient, the energy loss function spectra, and the refractive index, are investigated and the results show, in general, a red-shift in all these parameters compared to those of the bulk form. Also, it exhibits metallic and semiconducting behaviors in reply to in-plane and perpendicular incident light beams, respectively.