Angular Dependence of Fluctuation Conductivity in BaFe1.9Co0.1As2 Single Crystal
© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Fluctuation conductivity of electron-doped BaFe1.9Co0.1As2 single crystal is investigated by measurement of electrical resistivity under magnetic fields up to 13 T at different angles of θ = 0̊, 45̊ and 90̊ near mean-field transition temperature, where θ is the angle between the applied magnetic field and the axis perpendicular to the ab plane. The mean-field transition temperature is determined using the peak of dR/dT curves. Using the Aslamazov–Larkin theory, four main regions are identified corresponding to 3D, 2D, 1D, and SW regions, respectively, for each angle at different magnetic fields. The 1D region is a sign of conducting charge strips that are believed that these 1D conducting strips might be responsible for the occurrence of high-temperature superconductivity. Anisotropy increases as it approaches Tc, suggesting unconventional superconductivity that might be due to multiband effects in crystal. Results show that the zero-temperature coherence length in the c-direction ξ(0), the effective distance between the conducting layers d, and the channel cross section s decrease with increase in the magnetic field.