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arXiv · 0809.1133

Doping dependence of upper critical field and Hall resistivity in LaFeAsO1-xFx

Y. Kohama·Y. Kamihara·S. A. Baily·L. Civale·S. C. Riggs·F. F. Balakirev·T. Atake·M. Jaime·M. Hirano·H. Hosono
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Abstract

The electrical resistivity (Rxx) and Hall resistivity (Rxy) of LaFeAsO1-xFx have been measured over a wide fluorine doping range 0 =< x =< 0.14 using 60 T pulsed magnets. While the superconducting phase diagram (Tc, x) displays the classic dome-shaped structure, we find that the resistive upper critical field (Hc2) increases monotonically with decreasing fluorine concentration, with the largest Hc2 >= 75 T for x = 0.05. This is reminiscent of the composition dependence in high-Tc cuprates and might correlate with opening of a pseudo-gap in the underdoped region. Further, the temperature dependence of Hc2(T) for superconducting samples can be understood in terms of multi-band superconductivity. Rxy data for non-superconducting samples show non-linear field dependence, which is also consistent with a multi-carrier scenario.

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Y. Kohama, Y. Kamihara, S. A. Baily, L. Civale, S. C. Riggs, F. F. Balakirev, T. Atake, M. Jaime, M. Hirano, H. Hosono. 2008-09-06. Doping dependence of upper critical field and Hall resistivity in LaFeAsO1-xFx. https://doi.org/10.1103/physrevb.79.144527

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