Sulfur doped FeSe: A first-principles study of its electronic and superconducting properties

Abstract

The self-consistent first-principles calculations, based on density functional theory (DFT) approach and the Green’s-function-based Korringa-Kohn-Rostoker Atomic Sphere Approximation (KKR-ASA) method within coherent potential approximation (CPA), are performed to investigate the electronic and superconducting properties of FeSe1-xSx (x = 0.0, 0.05) alloys. The spin-unpolarized calculations show a significant effect on the electronic structure for the substitution of S in FeSe. The outcome for electronic and superconducting properties have been examined in terms of changes in the density of states, band structure, Fermi surface, bare Sommerfeld constant, Hopfield parameters, and the superconducting transition temperature (Tc) of FeSe and FeSe0.95S0.05 alloys, respectively. All calculated results in terms of Tc compare well with the available experimental data. It hopes that the studied properties of these alloys would give the possibility to understand the new physics of iron-based superconductors experimentally.