Large pinning forces in Nb-doped Y123 Superconductor with CuO nanoparticles

We have investigated the effect of Niobium and Nano CuO (40 nm) dopingY1-xNbxBa2Cu3O7-∂ compounds with 0.00 ≤ x ≤ 0.05 wt. %, prepared by the conventional solid-state method by means of XRD, SEM, R(T) and magnetic loops (M-H) measurements. The critical current densities, Jc as a function of temperature have been calculated using the critical state model from the hysteresis loops up to 1 kG at the temperature range of 10-60 K. Magnetic flux pinning, Fp of samples was calculated by using Lorentz force. The temperature dependence of the electrical resistivity measurement curves indicated that the sample with x=0.01 wt.% has a high transition temperature, Tc. XRD analysis shows a shorter c axis lattice parameter and higher orthoromthcity than the pure Y-123 and other Nb-doped samples. It was also found from Jc and Fp measurement, that the 0.01 wt.% Nb substation for the Y on YBCO superconductor improves the Jc and Fp.