راحله حاجیلو
حسن صدقی - استاد-دانشگاه ارومیه

We have investigated the effect of Niobium and Nano CuO (۴۰ nm) dopingY۱-xNbxBa۲Cu۳O۷-∂ compounds with ۰.۰۰ ≤ x ≤ ۰.۰۵ wt. %, prepared by the conventional solid-state method by means of XRD, SEM, R(T) and magnetic loops (MH) 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 ۱ kG at the temperature range of ۱۰-۶۰ 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=۰.۰۱ wt.% has a high transition temperature, Tc. XRD analysis shows a shorter c axis lattice parameter and higher orthoromthcity than the pure Y-۱۲۳ and other Nb-doped samples. It was also found from Jc and Fp measurement, that the ۰.۰۱ wt.% Nb substation for the Y on YBCO superconductor improves the Jc and Fp.

high-Tc superconductors, x-ray, Critical current density (Jc), Flux pinning (Fp)