Effect of artificial pinning centers on YBCO high temperature superconductor through substitution of graphene nano-platelets

Abstract

Abstract We report the structural modification and superconducting parameters variation of YBa2Cu3O7-δ (YBCO) high temperature superconductor (HTSC) with addition of different wt. % of GnPs (0.0, 0.5, 1.0, 2.0 & 3.0 wt. %) synthesized by standard solid state reaction route. The orthorhombic structures of all the samples with Pmmm space group were confirmed from the XRD analysis through Rietveld refinements. No significant variation is observed in the lattice parameters of the orthorhombic structure of YBCO superconducting matrix with increasing wt. % of GnPs. The Field emission scanning electron microscope (FESEM) analysis shows better connectivity between the grains of GnPs doped samples. From the observed ρ vs. T measurement it is observed that there is no chemical reaction between superconductivity and GnPs, rather addition of GnPs reduced the room temperature resistivity and more importantly enhances the critical temperature ( T C on ). Rather from it, there is an enhancement of critical current density value observed for GnPs substituted TBCO samples. By the application of 0.4 T external magnetic fields, the value of critical current density for 2.0 wt. % GnPs doped sample is maximum and nearly 12 times more than that of pristine YBCO.