Superconducting properties in heavily overdoped Ba(Fe0.86Co0.14)(2)As-2 single crystals

Abstract

We report the intrinsic superconducting parameters in a heavily overdoped Ba(Fe1-xCox)(2)As-2 (x=0.14) single crystal and their influence in the resulting vortex dynamics. We find a bulk superconducting critical temperature of 9.8 K, magnetic penetration depth lambda(ab) (0)=660 +/- 50 nm, coherence length xi(ab) (0)=6.4 +/- 0.2 nm, and the upper critical field anisotropy gamma(T -> Tc) approximate to 3.7. The vortex phase diagram, in comparison with the optimally doped compound, presents a narrow collective creep regime. The intrinsic pinning energy plays an important role in the resulting vortex dynamics as compared with similar pinning landscape and comparable intrinsic thermal fluctuations. (C) 2014 Elsevier Ltd. All rights reserved.