Magnetoresistance studies of PbO addition in YBa2Cu3O7-δ superconductor

The effect of PbO addition on the superconducting properties of YBa2Cu3O7-delta(Y-123) polycrystalline phase has been investigated through samples with x wt.% PbO (x = 0 - 4.5) addition prepared using standard solid state reaction method. Electrical transport measurements indicate that samples with x = 1-3 have their current density, at self magnetic field, J(0), increased about 50%. Their magnetic field dependent J(c) (H) has been measured in liquid nitrogen, and the activation energies have been determined using the TAFF model which shows an enhanced flux pinning proprieties. TEM and EDX analyses have shown that Pb reacts with Y-123 phase to form nanometric Pb-rich phase intergrown in Y-123 superconductors matrix. These inhomogeneities may be the origin of strong pinning.