Electronic Behavior and Optical Properties of New Ferromagnetic Silver-Based Sulfo-spinel: AgV2S4

Abstract

This study reports the intriguing properties of a novel ternary silver-based sulfo-spinel vanadium system (AgV2S4) having a face centered cubic structure (FCC). The magnetic nature, electronic behavior and optical properties of this system are revealed. The calculations were performed with spin-effect and by using generalized gradient approximation (GGA) under Density Functional Theory (DFT). After obtaining the optimized Wyckoff positions for the atoms in the crystal structure of this composition, it was decided that this spinel material has ferromagnetic nature in view of the energy-volume curves obtained for three different magnetic phases and of the calculated cohesive energies. Furthermore, the spin-polarized electronic band structure with the orbital projected density of electronic states was calculated within first principles to investigate its electronic behavior and bonding characteristic in detail. The observed small band gap in minority spin channel is Eg = 0.41 eV, so its electronic band structure imply that this system has half-metallic character. Finally, to evaluate some optical features, frequency dependent complex dielectric functions were calculated. Then, some optical properties were investigated by using the real and imaginary parts of the dielectric function.