Open AccessStudy on the electronic structures of Iridium-doped SmOFeAs under the strongly correlated electrons effects
Author(s) -
Pan Min,
Hui Zheng,
Yong Zhao
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.217401
Subject(s) - doping , iridium , atomic orbital , coulomb , fermi level , x ray photoelectron spectroscopy , condensed matter physics , electron , tetrahedron , density functional theory , photoemission spectroscopy , materials science , electronic structure , angle resolved photoemission spectroscopy , superconductivity , fermi energy , electronic correlation , atomic physics , physics , quantum mechanics , nuclear magnetic resonance , crystallography , chemistry , biochemistry , catalysis
Based on the consideration of strong correlation of electrons, we have used density functional theory generalized gradient approximation method SGGA+U to calculate SmFeAsO and Ir doping effects on the lattices and electronic properties. It is found that iridium doping at the Fe site enhances the interaction between FeAs and SmO layers and results in a modification of the FeAs4 tetrahedron. The electronic density of states (DOS) of SmOFe1-xIrxAs is studied by comparing the calculations with the X-ray photoemission spectroscopy experiments (XPS). It is revealed that the Fe 3d and As 4p hybridization orbits dominate the electric properties for SmOFe1-xIrxAs. Ir doping makes the five orbitals of Fe3d all filled. Superconductivity is sensitive to the peak position shifting away from Fermi level. Our VASP SGGA+U calculation provides a better agreement with the experimental results when we use an on-site coulomb energy of U on Fe 3d shell, which is sharply contrasted to the GGA process.