Intrinsic superconducting properties and vortex dynamics in heavily overdoped Ba(Fe${}_{0.86}$Co${}_{0.14}$)${}_2$As${}_2$ single crystal

In this work we report the influence of intrinsic superconducting parameters on the vortex dynamics in an overdoped Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ (x=0.14) single crystal. We find a superconducting critical temperature of 13.5 K, magnetic penetration depth ${\lambda }_{ab}$(0) = 660 $\pm$ 50 nm, coherence length ${\xi }_{ab}$(0) = 5 nm, and the upper critical field anisotropy ${\gamma }_{T\to Tc}$ $\approx$ 3.7. In fact, the Ginzburg-Landau model may explain the angular dependent $H_{c2}$ for this anisotropic three-dimensional superconductor. The vortex phase diagram, in comparison with the optimally doped compound, presents a narrow collective creep regime. In addition, we found no sign of correlated pinning along the c axis. Our results show that vortex core to defect size ratio and $\lambda$ play an important role in the resulting vortex dynamics in materials with similar intrinsic thermal fluctuations.