Fluctuating magnetism of Co- and Cu-doped NaFeAs

Abstract

We report an x-ray emission spectroscopy (XES) study of the local fluctuating magnetic moment (${\mu }_{bare}$) in $\mathrm{NaF}{\mathrm{e}}_{1-\mathrm{x}}\mathrm{C}{\mathrm{o}}_{\mathrm{x}}\mathrm{As}$ and $\mathrm{NaF}{\mathrm{e}}_{1-\mathrm{x}}\mathrm{C}{\mathrm{u}}_{\mathrm{x}}\mathrm{As}$. In NaFeAs, the reduced height of the As ions induces a local magnetic moment higher than $\mathrm{B}{\mathrm{a}}_2\mathrm{A}{\mathrm{s}}_2$, despite lower T${}_N$ and ordered magnetic moment. As NaFeAs is doped with Co ${\mu }_{bare}$ is slightly reduced, whereas Cu doping leaves it unaffected, indicating a different doping mechanism: based on electron counting for Co whereas impurity scattering dominates in the case of Cu. Finally, we observe an increase of ${\mu }_{bare}$ with temperature in all samples as observed in electron- and hole-doped $\mathrm{BaF}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$. Since both Co and Cu doping display superconductivity, our findings demonstrate that the formation of Cooper pairs is not connected with the complete loss of fluctuating paramagnetic moments.

17 pages, 4 figures, 1 table

References in corpus (27)

• Strong electronic correlations from Hund's coupling
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Where Are the Extra d Electrons in Transition-Metal Substituted Fe Pnictides?
• Dichotomy between large local and small ordered magnetic moment in Iron-based superconductors
• Dependence of carrier doping on the impurity potential in transition-metal-substituted FeAs-based superconductors
• Observation of an Orbital Selective Electron-Mode Coupling in Fe-Based High-$T_c$ Superconductors
• Electron-Hole Asymmetry in Superconductivity of Pnictides Originated from the Observed Rigid Chemical Potential Shift
• ARPES studies of the electronic structure of LaOFe(P,As)
• Extraordinary quasiparticle scattering and bandwidth-control by dopants in iron-based superconductors
• Spin-state transition in the Fe-pnictides
• Anisotropic but nodeless superconducting gap in the presence of spin density wave in iron-pnictide superconductor NaFe1-xCoxAs
• A novel non-Fermi-liquid state in the iron-pnictide FeCrAs
• Structural origin of the anomalous temperature dependence of the local magnetic moments in the CaFe${}_2$As${}_2$ family of materials
• The magnetic moment enigma in Fe-based high temperature superconductors
• Anisotropic neutron spin resonance in underdoped superconducting NaFe1-xCoxAs
• Coexistence of different electronic phases in the K0.8Fe1.6Se2 superconductor: a bulk-sensitive hard x-rays spectroscopy study
• Effect of nematic order on the low-energy spin fluctuations in detwinned BaFe${}_{1.935}$Ni${}_{0.065}$As${}_2$
• Local and collective magnetism of EuFe${}_2$As${}_2$
• Intra-layer doping effects on the high-energy magnetic correlations in NaFeAs
• The anomaly Cu doping effects on LiFeAs superconductors
• NaFe${}_{0.56}$Cu${}_{0.44}$As: A pnictide insulating phase induced by on-site Coulomb interaction
• Temperature dependence of iron local magnetic moment in phase-separated superconducting chalcogenide
• Presence of magnetic excitations in SmFeAsO
• Phase diagram and neutron spin resonance of superconducting NaFe${}_{1-x}$Cu${}_x$As
• Orbital-selective Mott phase of Cu-substituted iron-based Superconductors

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