Investigation and Comparing the Effects of CNTs and Ag Nanoparticles Doping on YBCO Superconductor Properties

In this work, we investigate and compare doping effects of Ag nanoparticles and carbon nanotubes (CNTs) on the properties of Y₁Ba₂Cu₃ O _7?δ (YBCO) high-temperature superconductor. The YBCO samples were prepared using sol-gel method and characterized by resistivity versus temperature (ρ–T), the electrical field versus current density (E–J), x-ray diffraction (XRD) and scanning electron microscope (SEM) analysis. The results show that the orthorhombic phase of superconductivity was formed for all the prepared samples. Also, we found that the crystalline size of the YBCO samples decreases from 62 to 33 nm by adding CNTs and Ag nanoparticles to the compound. The pinning energy, critical current density and critical temperature of the samples increase by adding CNTs and Ag nanoparticles to YBCO compound, but CNTs play a more effective role than Ag nanoparticles in this compound.