Excess conductivity studies of TI1.XCUXSR1.8YBO.2CACU207-6 superconductor and dimensionality of superconducting fluctuation / Shabani Ismail

Effects of Cu substitutions at Tl-site, respectively, on superconducting and normal state behaviors of Tli^CutSrigYbo^CaC^OT-s (x = 0-0.6) ceramics have been investigated. Temperature-dependent resistance measurements on Tli^Cu^SrisYbo^CaC^Oy-s (x = 0- 0.6) showed optimum superconductivity for x=0.4 with Tc onset of 92.5K and Tc :ero of 77.6K. In addition, superconducting fluctuation was studied in sintered polycrystalline sample of Tli^CutSruYbo^CaC^O?^ (x = 0-0.4) by electrical resistivity measurement.The behavior of excess conductivity with Cu-substitution was investigated. Analysis of excess conductivity based on Aslamazov - Larkin (AL) theory revealed transition from 2D to 3D behavior of superconducting fluctuation in the mean-field region -4< In 8 <-l for samples (x = 0-0.4). The studied also suggest that there is a close correlation between the amounts of Cu-substitution and the behavior of superconducting fluctuation constant (AL) both 2D and 3D fluctuation. Increase the Cu-substitution caused the superconducting fluctuation constant (AL) for 2D generally decrease but for 3D showed no trend. The superconducting fluctuation constant (AL) both 2D and 3D showed optimum value for x = 0.1 with A2D of 0.13 and A3D of 0.21