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arXiv · 1101.6027

Anisotropic Phase Diagram and Superconducting Fluctuations in SmFeAsO0.85F0.15

U. Welp·C. Chaparro·A. E. Koshelev·W. K. Kwok·A. Rydh·N. D. Zhigadlo·J. Karpinski·S. Weyeneth
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Abstract

We report on the specific heat determination of the anisotropic phase diagram of single crystals of optimally doped SmFeAsO1-xFx. In zero-field, the optimally doped compound displays a clear cusp-like anomaly in C/T with ΔC/Tc = 24 mJ/molK2 at Tc = 49.5 K. In magnetic fields applied along the c-axis, we find pronounced superconducting fluctuations induced broadening and suppression of the specific heat anomaly which can be described using three-dimensional lowest-Landau-level scaling with an upper critical field slope of -3.5 T/K and an anisotropy of Γ = 8. The small value of ΔC/Tc yields a Sommerfeld coefficient γ ~ 8 mJ/molK2 indicating that SmFeAsO1-xFx is characterized by a modest density of states and strong coupling.

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U. Welp, C. Chaparro, A. E. Koshelev, W. K. Kwok, A. Rydh, N. D. Zhigadlo, J. Karpinski, S. Weyeneth. 2011-01-31. Anisotropic Phase Diagram and Superconducting Fluctuations in SmFeAsO0.85F0.15. https://doi.org/10.1103/physrevb.83.100513

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