Ab initio study of 5d-shells Ir substitution for Fe-based SmOFe1−xIrxAs

The lattice and electronic properties for 5d-shells Ir substituted Fe-based superconductor SmOFe1−xIrxAs (x=0,0.2,0.25,0.3) are investigated based on the density functional theory (DFT) with a spin generalized gradient approximation SGGA+U method. The electronic density of states (DOS) of SmOFe1−xIrxAs is studied and well compared with the results of experimental X-ray photoemission spectroscopy (XPS). The calculation indicated that iridium substitution at the Fe site induced a modification of the FeAs4 tetrahedron and suppressed the magnetic ordering corresponding to the Fe-3d, which may be the main cause of inducing superconductivity in Ir-doped SmOFeAs system.