Silver (Ag) nano-sized particles were prepared using the Sol–gel technique and then mixed with a (Cu0.5Tl0.5)Ba2Ca2Cu3O10-δ superconductor to produce (Ag)x/CuTl-1223; x \(\sim\) 2.0 wt.% nano-particles superconducting composites. The synthesized samples were pelletized at both low hydraulic pressure (100 MPa) and high pressure (0.4 GPa) using a cold isostatic press (CIP). The structure, morphology, composition, vibrational modes of oxygen, and superconducting properties of prepared nanocomposites were analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and four-probe resistivity measurements, respectively. XRD analysis confirmed that the major phase is CuTl-1223 tetragonal matrix, and no pronounced change was observed in the lattice parameters with the application of high pressure. EDX reveals the presence of Ag nanoparticles in the samples. SEM micrographs indicate that high pressure compresses inter-grain regions and reduces voids, enhancing connectivity and improving electrical transport properties. Resistivity measurements show that the critical temperature Tc (0) and activation energy (Uo) of CuTl-1223 superconductor increases with the inclusion of nanoparticles up to 2.0 wt.% and are further enhanced under high pressure using CIP. The improved superconducting properties are attributed to the conducting nature of Ag NPs that fills the inter-grain voids and facilitates the conduction process across the grains. Additionally, high pelletization pressure reduces the porosity by forcing the grains close together, thereby increasing the superconducting volume fraction and further boots superconductivity.
