Comparisons of the Magnetic and Half-Metallic Properties of Sb-V-Te Compounds in Low and Rich Vanadium Region

The electronic, magnetic, and half-metallic properties of Sb x V 1-x Te ( x = 0.0625, 0.125, 0.25, 0.75, 0.875, and 0.9375) compounds were investigated by first-principles method using WIEN2k computational program. First, SbTe compound obtained a non-magnetic character. Second, the structural properties of compounds were formed by V-addition. The ferromagnetic phases were obtained as the most energetically stable phases in each ratio. Then according to electronic calculations, compounds formed at the V-low region showed metallic character, while band gaps were observed in minority electrons in the V-rich region. In GGA method, the indirect band gaps around the Fermi energy level were calculated as 1.304 eV for Sb 0.0625 V 0.9375 Te, 1.008 eV for Sb 0.125 V 0.875 Te, and 1.063 eV for Sb 0.25 V 0.75 Te compounds. The band gaps were also investigated by using GGA + U method for U = 1, 2, 3, 4, and 5 eV. As the U values increased, the band gaps decreased in Sb 0.25 V 0.75 Te and Sb 0.125 V 0.875 Te compounds. Although the U values affect the band gaps compared to the GGA, there was no change in the magnetic properties. The total magnetic moments of cells were obtained as 46.0 μ B /cell for Sb 0.0625 V 0.9375 Te, 22.0 μ B /cell for Sb 0.125 V 0.875 Te, and 10.0 μ B /cell for Sb 0.25 V 0.75 Te compounds, respectively. Finally, the elastic stability conditions were provided by the V-rich Sb-V-Te compounds.