AC susceptibility investigation of YBCO superconductor added by carbon nanotubes

We report in this investigation the preparation as well as characterization of bulk YBa2Cu3O7-delta superconductor produced by solid state reaction route and added by various amount (x) of CNTs (x = 0.0, 0.1 and 1.0 wt%). The analysis of X-ray diffraction (XRD) indicated the achievement of orthorhombic structure of YBCO phase for various sintered samples. No relevant variations in the lattice parameters is observed with CNTs inclusion. The analysis of microstructure revealed a dispersion of CNTs into YBCO and presence of lattice defects for CNTs added samples. We evaluated the impacts of CNTs on intergranular traits of YBCO using AC susceptibility measurements. Various superconducting parameter including critical temperature (T-c), inter-granular critical current density (J(c inter) ), grain volume fraction (f(g)), grains susceptibility (chi(g)) and matrix susceptibility (chi(m)) were estimated and deeply discussed. The obtained results confirm that the CNTs addition has a beneficial role on the inter-granular properties of YBCO system. Also, the critical current density J(cm) . was determined and its value has been shown to be greatly enhanced with the addition of CNTs in the existence of the applied magnetic field. (C) 2019 Elsevier B.V. All rights reserved.