Where Are the Extra d Electrons in Transition-Metal Substituted Fe Pnictides?

Abstract

Transition-metal substitution in Fe pnictides leading to superconductivity is usually interpreted in terms of carrier doping to the system. We report on a density functional calculation of the local substitute electron density and demonstrate that substitutions like Co and Ni for Fe do not carrier dope but rather are isovalent to Fe. We find that the extra d electrons for Co and Ni are almost totally located within the muffin-tin sphere of the substituted site. We suggest that Co and Ni act more like random scatterers scrambling momentum space and washing out parts of the Fermi surface.

4 pages, 5 figures

References in corpus (7)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO
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Cited by in corpus (7)

• High-temperature superconductivity in iron-based materials
• On the multi-orbital band structure and itinerant magnetism of iron-based superconductors
• Magnetoelastic Coupling in the Phase Diagram of Ba1-xKxFe2As2
• Electron-Hole Asymmetry in Superconductivity of Pnictides Originated from the Observed Rigid Chemical Potential Shift
• Upper critical field anisotropy in BaFe2-xCoxAs2 single crystals synthesized without flux
• Spatial Inhomogeneity in RFeAsO1-xFx (R =Pr, Nd) Determined from Rare Earth Crystal Field Excitations
• Revealing the degree of magnetic frustration by non-magnetic impurities