Excess conductivity analysis for Tl0.8Hg0.2Ba2Ca2Cu3O9−δ substituted by Sm and Yb

A series of superconducting samples of type Tl0.8Hg0.2Ba2Ca2−xRxCu3O9−δ, where R=Sm and Yb with 0≤x≤0.150≤x≤0.15, were prepared in a sealed quartz tube via a solid-state reaction technique. The electrical resistivity ρ(T)ρ(T) was measured as a function of temperature using the conventional dc four-probe technique. The fluctuation conductivity Δσ, above the superconducting transition temperature TcTc, was analyzed as a function of temperature using the Aslamazov and Larkin model. It exhibits five different fluctuation regions namely critical (cr), three-dimensional (3D), two-dimensional (2D), one-dimensional (1D) and short-wave (sw). The zero-temperature coherence length, the effective layer thickness of the two dimensional system, the wire cross-sectional area for one dimensional systems and the inter-layer coupling strength were estimated as a function of the substitution-content xx. Furthermore, the thermodynamics critical field, lower critical magnetic field, upper critical magnetic field, critical current density and Fermi energy are calculated from the Ginzburg number.