Enhancing grains connectivity and superconductivity in (Cu)_x/CuTl-1223 nano-particles superconductor composites under high pelletize pressure

This study investigates the enhancement of superconducting properties in Cu_0.5Tl_0.5Ba₂Ca₂Cu₃O_10-δ superconductor via inclusion of Cu nano-particles (Cu NPs) and high-pressure pelletization. The (Cu)_x/CuTl-1223 nano-particles superconductor composites were synthesized by solid-state reaction technique and pelletized using a cold isostatic press (CIP). X-ray diffraction analysis confirmed the retention of tetragonal crystal structure and dominant CuTl-1223 phases in the nanocomposites. SEM images showed a decrease in the density of void/pores as well as an improvement in weak-link connections. FTIR spectra indicated no significant changes in the vibrational oxygen modes, confirming that the crystal structure remained intact. Resistivity ( \(\rho\) $\rho$ ) measurements unveiled a remarkable boost in the critical temperature \({T}_{c(0)}\) $T_{c(0)}$ to 110 K and activation energy (U_o) to 0.028 eV at the optimal 1.5 wt.% of copper (Cu) nano-particle concentrations, and decreasing beyond these concentrations at 0.4 GPa. This enhancement of superconducting parameters is attributed to improved weak-link connectivity, reduced porosity, and increased superconducting volume fraction, leading to higher carrier charge concentrations in the (Cu)_x/CuTl-1223 nanocomposites.