Ferromagnetic (Ni) nanoparticles–CuTl-1223 superconductor composites

Abstract (Ni)x/CuTl-1223 (x=0, 0.25, 0.75, and 1.0 wt%) nanoparticles–superconductor composites were synthesized by the addition of ferromagnetic nickel (Ni) nanoparticles in appropriate ratio to Cu0.5Tl0.5Ba2Ca2Cu3O10−δ (CuTl-1223) superconducting matrix. Structural, morphological, compositional and superconducting transport properties of these composites were studied by different experimental techniques. It was observed that the addition of Ni nanoparticles had not altered the crystal structure of host CuTl-1223 phase, which is somehow an evidence of the occupancy of these nanoparticles at the grain-boundaries. Suppression of superconducting properties was attributed to pair-breaking due to spin scattering across these ferromagnetic Ni nanoparticles. The enhanced magnetization of ferromagnetic Ni nanoparticles at reduced temperatures plays a significant role to reduce the diamagnetism of (Ni)x/CuTl-1223 composites. Fluctuation induced conductivity (FIC) analysis of resistivity versus temperature data has explained very well the effects of Ni nanoparticles on superconductivity of CuTl-1223 phase.