Study of CuO Nano-particles/CuTl-1223 Superconductor Composite

Synthesis and characterization of (CuO) x /Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10− δ ; {(CuO) x /CuTl-1223} composites with x =0 %, 10 %, 15 % and 20 % have been reported. The fluctuations induced conductivity (FIC) analysis of (CuO) x /CuTl-1223 composite has been carried out using Aslamazov-Larkin (AL) and Lawrence-Doniach (LD) models in the temperature regime well above the critical temperature ( T > T c ). The electrical resistivity versus temperature curves of as-prepared and oxygen post-annealed (CuO) x /CuTl-1223 composite were fitted by using above mentioned models to extract the microscopic parameters such as zero temperature coherence length along c -axis{ ξ c (0)}, inter-layer coupling ( J ), dimensional critical exponent ( λ ) and inter-grain coupling constant ( α ) etc. It has been observed that the cross-over temperature ( T o ) fits very well the two-dimensional (2D) and three-dimensional (3D) AL equations and shifts towards the lower temperature regime with the enhanced weight percentage of CuO nano-particles. The shifting of AL 3D region to higher temperature after oxygen post-annealing indicates the restoration of oxygen and optimization of charge carriers in conducting CuO 2 planes. The gradual decrease in the value of inter-grain coupling constant ( α ) with the increase of CuO nano-particles content reflects an improvement in the inter-grain coupling resulting into an increase in the coherence length ( ξ c ) along the c -axis. Almost all superconductivity parameters have been improved after oxygen post-annealing. The suppression of superconductivity parameters in the composite with x =20 % limits the optimum doping level of CuO nano-particles in (CuO) x /CuTl-1223 composite.