Magnetism and optical spectral of half-metallic BaX (X = N, P, As)

The generalized gradient approximation (GGA) to the density-functional theory in the pseudopotential planewave-formalism has been used to investigate the electronic structures, magnetic and optical properties of the NiAs-tape BaX (X = N, P and As) compounds. Electronic structures of these compounds that do not contain transition metal or rare earth elements indicate that they are ferromagnetic half-metal, and their magnetic moments mainly originate from the spin polarization of the anion atomic p-orbits and d-orbits of barium atoms. We also calculate the optical properties (dielectric, absorption, and energy loss function) of these compounds, and show that the half-metal characteristic of these compounds gives rise to some features in optical spectrum.