Details

Autor(en) / Beteiligte

• Hess, C
• Kondrat, A
• Narduzzo, A
• Hamann-Borrero, J. E
• Klingeler, R
• Werner, J
• Behr, G
• Büchner, B

Titel

The intrinsic electronic phase diagram of iron-oxypnictide superconductors

Ist Teil von

• Europhysics letters, 2009-07, Vol.87 (1), p.17005-p1-6

Ort / Verlag

IOP Publishing

Erscheinungsjahr

2009

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We present the first comprehensive derivation of the intrinsic electronic phase diagram of the iron-oxypnictide superconductors in the normal state based on the analysis of the electrical resistivity ρ of both LaFeAsO$_{1- x}$Fx and SmFeAsO$_{1- x}$Fx for a wide range of doping. Our data give clear-cut evidence for unusual normal-state properties in these new materials. In particular, the emergence of superconductivity at low doping levels is accompanied by distinct anomalous transport behavior in ρ of the normal state which is reminiscent of the spin-density wave (SDW) signature in the parent material. At higher doping levels ρ of LaFeAsO$_{1-x}$Fx shows a clear transition from this pseudogap-like behavior to Fermi-liquid–like behavior, mimicking the phase diagram of the cuprates. Moreover, our data reveal a correlation between the strength of the anomalous features and the stability of the superconducting phase. The pseudogap-like features become stronger in SmFeAsO$_{1-x}$Fx where superconductivity is enhanced and vanish when superconductivity is reduced in the doping region with Fermi-liquid–like behavior.