Metallic Cu Nanoparticles Added to Cu0.5Tl0.5Ba2Ca2Cu3O10−δ Superconductor

Abstract

Metallic copper (Cu) nanoparticles were added in appropriate ratios into the Cu0.5Tl0.5Ba2Ca2Cu3O10−δ (CuTl-1223) superconducting phase to obtain (Cu) x /CuTl-1223 (x = 0 ∼ 4.0 wt%) nanoparticle-superconductor composites. Structural, morphological, compositional, and superconducting transport properties were investigated by using different experimental characterization techniques. The crystal structure of the host CuTl-1223 phase remained unaltered (i.e. tetragonal) after addition of Cu nanoparticles, which gave a clue about the occupancy of these nanoparticles at the inter-crystallite sites. Grain morphology and inter-grain connectivity were improved after addition of these Cu nanoparticles being metallic in nature were supposed to be the best candidate for improvement of inter-grain connectivity and superconducting properties. Calculation of the superconducting volume fraction showed the dominance of the CuTl-1223 phase along with the presence of some other superconducting phases and unknown impurities. The optimum content level of Cu nanoparticles in the CuTl-1223 phase for maximum improvement of superconducting properties was 1.0 wt%.